Re: [avr-gcc-list] basic UART problem / example

[Parthasaradhi Nayani]

Hello,

A lot about serial port programming has been discussed
in the avrfreaks forum. This is the best place to get
answers.

Nayani P


--- Przemek Urbanski [EMAIL PROTECTED] wrote:

 Hey,
 
 I am new to avr programming. I can not get my
 at90s8515 talk to rs232. I
 wrote basic interrupt driven program for at90s8515
 talking via UART to
 rs232 on my PC. Compiled using CodeVisionAVR. It
 worked fine.
 
 Now I am using:
 
 avr-gcc (GCC) 3.4.4
 binutils 2.15
 avr-libc 1.2.3
 
 on linux (Fedora Core 3)
 
 Could you please send me, or point me any UART
 examples, which works compiled with avr-gcc?
 
 Thnx AVR freaks :
 P
 
 
 

--
 Zobacz projekt nowej strony glownej portalu
 INTERIA.PL
  http://link.interia.pl/f188f 
 
 
 
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Re: [avr-gcc-list] PEN on atmega128

[Parthasaradhi Nayani]

--- Torsten Mohr [EMAIL PROTECTED] wrote:

 
 i wonder if anybody ever successfully used an
 ATMega128?  I always
 assumed that.

We have been using ATMega128 without any problems for
more than a year. We use the SPI bus to program the
chip with AVRISP. On some occations used JTAG
programmer. 
 
 Has anything changed in the specs?
 
 Does anybody else experience problems with this
 chip?
 
 Regarding PEN, as it is not on the programming
 connector i think
 it just has to be either low or high, but can not be
 changed during
 programming, right?

Though I dont have the schematics right now, AFAIK,
ISP uses RESET, MISO,MOSI and the SS pins only. PEN is
to be left un-connected.


 
 I found out that after disconnecting the power i can
 do exactly one
 step of either:
 
 - erase
 - program
 - verify
 
 Now i got the problem that the program does not do
 what i
 expect it to do:
 
 
 int main(void) {
   volatile unsigned int i;
   volatile unsigned char p = 0;
 
   WDTCR = 0x1f;
   WDTCR = 0x00;
 
   DDRD = 0xFF;
   PORTD = 0x0f;
 
   DDRB = 0xFF;
   PORTB = 0x0f;
 
   do {
 PORTB = p++;
 
 //while (PINB  0x01);
 
 //for(i = 0; i  100; i++);
 
   } while(1);
 
   return 0;
 }
 
 Is there an obvious error in it?  I can't see the
 pattern 0x0f on Port D
 and all pins on Port B are near 0 V.

To test this program, set optimization to 0 in make
file (O = 0).

 
 There is no external crystal soldered on the board,
 it should start and
 run anyway, right?

Yes it will work if you enable the internal osc of the
chip.

regards
Nayani P




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[avr-gcc-list] bootloader help

[Parthasaradhi Nayani]

Hello all,

Perhaps there is ready documentation on bootloader,
but I have not been able to get what I wanted. How
does one declare a programme to be bootloader program?
that is the code must be loaded in the bootsection
when I program the chip using avrisp. How does one set
the starting address of this code? this is needed as
there are different boot loader program sizes. I want
to laod programme in the boot section which will test
a port bit and jump to  if not low. From  I
want to laod a sample program which may pulse an LED.
How can I do this? Thank you all.

Regards
Nayani P




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Re: [avr-gcc-list] output current for ATMega128 on output pins

[Parthasaradhi Nayani]

Torsten,

AVR data sheets talk about 25 mA current per pin., but
there is some limitation on the total current drawn.
If you are planing to drive some LEDs (4/5) I think
you can drive them directly from the port pins. You
may consider sinking current to switch the LED ON
rather than on sourcing current.

Regards
Nayani P

--- Torsten Mohr [EMAIL PROTECTED] wrote:

 Hi,
 

 how much current i can output on a
 port.
 
 I'd like to drive some LEDs.




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Re: [avr-gcc-list] bootloader: replace bootloader with a new bootloader

[Parthasaradhi Nayani]

Hello,

This is something many wish, but unfortunately not
possible.

Nayani P


--- Torsten Mohr [EMAIL PROTECTED] wrote:

 Hi,
 
 i wonder if it is possible to replace a bootloader
 in an ATMega128
 with a new version.
 
 Is this possible in a secure way so that a power
 failure or communication
 failure does not leave the system in an inconsistent
 state?  So to say that
 it is possible to re-start the re-programming again
 after a failure?
 
 What design options need to be considered to do
 this?
 
 
 Best regards,
 Torsten.
 
 
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Re: [avr-gcc-list] memory layout for bootloader

[Parthasaradhi Nayani]

Hello,

if you want to place other functions in the bootloader
memory add the attribute to these functions as well.

Ideally one must set the address of .text to boot
address, as bootloader is a completely independent
program. I tested by putting the .text in the
bootloader section and it worked fine.

  Or are there some disadvantages in this way?

I found one disadvantage or rather I am looking for a
solution.

If one creates a complete program including the main
function and put .text in the bootloader memory, the
startup code, the interrupt vector table and ofcourse
the cleanup code are also added to the binary/hex
image. If one is not using any interrupts in the
bootloader, why waste this memory? similarly why
occupy some more memory for cleanup as this may never
be used?
I found this to be a disadvantage.

How does one avoid putting interrupt table and cleanup
code in the bootloader section? (this is what I am
looking for)
 
 I guess i use 0x1E000, as 0xF000 seems to be based
 on 16 bits
 per address, is that correct?

The data sheets talk about word address so you need to
get the byte address by shifting the bootloader
address , mentioned in the docs, left by 1

 
 I assume that the ATMega128 can execute program in
 all its 128kB,
 is that correct?

Yes.

 Can i really DISABLE SPI programming by fuse bit
 SPIEN?

Never tired this.

Regards
Nayani P





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Re: [avr-gcc-list] double precision bit representation

[Parthasaradhi Nayani]

Hello,

Currently avr-gcc supports only float and not double.
The byte pattern given in your query results in a
float value of -1.135254

Nayani P


--- Kitts [EMAIL PROTECTED] wrote:

 Hi all,
 
 I would like to know how a variable declared as
 double is represented with 
 avr-libc. What is the maximum and minimum values
 that it can represent and 
 with what resolution? I am performing floating point
 math which fails in 
 certain occasion where i think it shouldn't. Hence
 my query...
 
 For an example i have a double variable called
 TempDouble which is placed 
 at the following address in SRAM with each of the
 byte having the given 
 value. How do i interpret this value in decimal?
 
 Ram Address:  $0B6F   $0B70   $0B71   $0B72
 Value:00  50  91  3F
 
 Thanks in Advance.
 -- 
 Cheers!
 Kitts
 
 
 
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Re: [avr-gcc-list] simple USART (RS232) example for ATmega48

[Parthasaradhi Nayani]

--- [EMAIL PROTECTED] wrote:

 Hi all,
 
 i'm looking for a simple c (AVR-GCC) example program
 demonstrating the use of the 
 USART0 (as RS232) of my ATmega48.

Hello,

Here are some program snippets. The following
functions are written for Mega8. Please change the
name of registers if need be.


 
void USART_Init(void)
   { 
UBRRH = 0x00;
UBRRL= 47;  // 9600 baud rate for external
7.6 MHz crystal

UCSRB=0x98; 
UCSRC=0x86; 
   }

// send one byte converted to ASCII
 void sendbyte(unsigned char dat) //function to send
0x38 as '3' and '8' onto serial port
   {
unsigned char ftmp;

ftmp = (dat  4);
ftmp += (ftmp  9 ? 0x37 : 0x30);

sendchar(ftmp);  // transmit the character to
hyperterminal

ftmp=dat  0x0f;
ftmp += (ftmp  9 ? 0x37 : 0x30);
sendchar(ftmp);
   }

// send one ASCII character to serial port
  void sendchar(unsigned char dat)
  {
   UDR=dat;
   while(!(UCSRA  0x40));
UCSRA|= 0x40;
  }

// send a string to serial port
  void USART_TRANS(unsigned char *ptr)  
   {   
   while(*ptr)
{
 UDR=*ptr++;
 while (!(UCSRA  0x40));   //Wait for transmission
complete 
   UCSRA = 0x40;  
}
   } 

HTH

Nayani P





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RE: [avr-chat] Re: [avr-gcc-list] AVR ISP Error

[Parthasaradhi Nayani]

Hello everybody,

There is no switch in the ISP unit. One has to open the covers and there is a provision on the PCB to solder a two pin jumper (taken out of berg connector). Once the soldering is done, plug in the jumper and power up the unit and after a short while the jumper can be removed. Now the unit ready to program. 

Note: the power to the ISP is drawn from the target board and through the ISP programming connector. While the ISP unit is being upgraded, the MISO,MOSI and other pins must not be connected to the target board. Therefore use only power and ground pins of this ISP connector to power up the ISP unit. I do agree that this is a bit of a long procedure, but thats the system is designed.


Nayani
Jim Brooks [EMAIL PROTECTED] wrote:
There is no button in the AVRISP. In the docs somewhere it says to power theAVRISP( the led comes on, cycles colors and settles on green I think). Youshould not connect it to your target as this usually mungs communicationswith the micro's in the ISP. Once the AVRISP is idle(green status led),clock OK to program it.This is a real pain and your lucky. In my experience, a lot of the time, theISP will mung code in it's secondary MCU and become dead. Atmel has anappnote on recovering but I have yet to be successful.This message will happen every time you update studio, a choice I think abig mistake. The funcinality should have been left in AVRStudio and the ISPcode left frozen.Hope this helps.Let us know how you make out.Jim-Original Message-From:
 [EMAIL PROTECTED][mailto:[EMAIL PROTECTED] Behalf OfDaniel MayoSent: Thursday, August 25, 2005 6:23 AMTo: AVR GCC List; AVR ChatSubject: [avr-chat] Re: [avr-gcc-list] AVR ISP ErrorWhere is the 'program' button on the AVRISP?Andi Suhandi wrote:To Upgrade the firmware you have to:1. Turn off the STK2. Press "Program" Button on STK3. Turn on the power STK ("Program" button still pressed)4. Run the "Upgrade.exe" program in directory C:\Program Files\Atmel\AVRTools\STK500 Press "Start Upgrade" button5.Then you can release "Program Button"6. Wait till upgrade doneI hope it will helpAndi- Original Message -From: "Daniel Mayo" <[EMAIL PROTECTED]>To: "AVR GCC List" ; "AVR
 Chat"Sent: Thursday, August 25, 2005 3:17 AMSubject: [avr-gcc-list] AVR ISP ErrorI just got two new AVR ISPs from Digikey and am getting this error whenI try to connect to them via AVR Studio 4.11 Build 401 which seems to bethe latest at atmel.com"An AVRISP with firmware version 2.01 has been detected. The firmwarecorresponding to this installation of AVR Studio is 2.00. Press OK tolaunch the upgrade program to perform a downgrade, or Cancel withoutdowngrading. NOTE! Correct operation is not guaranteed if a downgradeis not performed."If I press Cancel it seems as though everything works.If I press Ok, AVR Studio launches the Atmel STK500/AVRISP Upgradeprogram but after doing something to the AVRISP so that the LED goes outit then reports that
 no programmer could be found, and thus no update isperformed, and then AVR Studio can't detect the AVRISP until I close AVRStudio AND cycle power to the AVRISP.How do I get rid of either the first warning or the error updating sothat I can resolve this?I have looked online at atmel.com and avrfreaks.com, with no luck.___AVR-GCC-list mailing listAVR-GCC-list@nongnu.orghttp://lists.nongnu.org/mailman/listinfo/avr-gcc-list___AVR-chat mailing listAVR-chat@nongnu.orghttp://lists.nongnu.org/mailman/listinfo/avr-chat___AVR-GCC-list mailing
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Re: [avr-gcc-list] Small program for UART not working

[Parthasaradhi Nayani]

Hello,

Some questions, which may lead to solving the problem.

1. Are ysing external crystal? if yes, did you set bit
to external crystal. If you aare using internal 4M
clock, then please refer the doc on possible baud
rates and their errors. If internal clock is used I
suggest you use lower baud rate (less than 115200) and
which has the least error.

2. One way to check if received data is correct or
not, switch ON some specific LEDs for a particular
byte received. example switch ON LED1 if received byte
is A, switch on LED2 if received byte is B etc. Since
you are shorting the TX and RX lines and if the
controller transmits A continously and if the same is
received or not can be verified. I hope this will
atleast give you some pointer to the actual problem.

Regards
Nayani




--- Gary Bi [EMAIL PROTECTED] wrote:

 Hi David and Ian,
 
 Thanks for the help. I checked the fuses for mega101
 mode, it did set to ON. I uncheck it in AVR studio
 and
 program it, but this did not make improvement to the
 issue.
 
 I shorted the PIN2 and PIN3 at the end of cable (the
 end plugs to PC RS232), I still can see the data was
 received through the loopback, demonstrated through
 LEDs on STK board. The RS232 cable is good, since I
 short the other end, I can see the chars typed
 displayed on the termial.
 
 I'm suspecting the baud rate was not set accurately
 in
 Atmega128L, so cause the reception of PC side is not
 synchronized. For example, if I set to 115200, but
 not
 accurate, the number could be set as 115000, so I
 have
 some errors in PC terminal.
 
 I tried to calculate the baud rate on scope, I found
 I
 can't get a exactly number, I can only get an
 estimate. Do you know if there's way to set the baud
 rate accurately?
 
 Thanks,
 Gary
 
 
 
 
 --- David Brown [EMAIL PROTECTED] wrote:
 
  Hi,
  
  Since you can see the data on your scope, and
  loopback works fine when
  shorting RX and TX pins, there seems to be nothing
  wrong with the
  microcontroller.  The things I would now check are
  the baud rate (using the
  scope), the RS-232 line drivers, the TX-RX
  orientation (I've fixed many
  communications problems by swapping the TX and RX
  lines !), the cable
  between the board and the PC (including the ground
  line), and the PC serial
  port.  It can be worth shorting the TX and RX pins
  at the board end of the
  cable and testing loop-back from the PC side using
  TTP.
  
  mvh.,
  
  David
  
  
  
   Hi David,
  
   Thanks for the info. I downloaded Tera Term Pro
  and
   installed it in my PC, it's a defenitely a
 better
   terminal simulation. Unfortunately I got the
 same
   result.
  
   My problem are:
  
   1. Atmel128L has successfully sent out
 characters
  in
   TX, but I can not receive it correctly in PC
  termimal.
   When monitoring the TX pin in scope, I can see
  char
   'B' has been sent out continuouly.
   /* UART Transmit Complete Interrupt Function */
   SIGNAL(SIG_UART0_TRANS){
   outp('B',UDR0);
   }
   When I short TX and RX pin together in Atmel STK
   board, I can see the 'B' was displayed correctly
   (demonstrated using LEDs, PIN7-0 is for Bit7-0).
   /* UART Receive Complete Interrupt Function */
   SIGNAL(SIG_UART0_RECV){
   RxChar = inp(UDR0);
   outp(RxChar, PORTB);
   }
   What I receivd in TTP teminal is 0xA2 instead of
   character 'B' (0x42).
  
   2. I did not set baud rate in the codes for
 Atmel,
  in
   TTP, I will need to set the baud rate to 57600,
  8-N-1
   to get the RX working, so if I type 'C', I can
 see
  the
   LEDs is demonstrated 'C' correctly. If the set
 the
   baud rate to 9600, 115200, etc. I can not get
 the
  Rx
   working. This is very strange.
   So I have to comment out the two lines for baud:
   //outp(0x0, UBRR0H);
   //outp( (u08)UART_BAUD_SELECT, UBRR0L);
  
   The MCU is running at 7.3728Mhz, I set the baud
   parameter to 0x2F according to the datasheet.
   #define UART_BAUD_SELECT 0x2F //9600 baud
  
   There's typo in my previous email, what I want
 to
  say
   is: I can see the character 'B' is sending out,
 I
  just
   did not receive it correctly in PC.
  
   3. Do you think it's possible it's related to a
  defect
   MCU (ATMEGA128L)? I'm trying to buy a new
  MCU(order
   ATMEGA128-16AI (16Mhz), but not sure if it will
  work
   with 7.3728MHz crystal on STK or not.
  
   Thanks,
   Gary
  
  
 

==
   #include avr/io.h
   #include avr/interrupt.h
   #include avr/signal.h
   #include avr/pgmspace.h
  
   #define outp(a,b) b=a
   #define inp(a) a
   typedef unsigned char  u08;
   typedef unsigned short u16;
   #define UART_BAUD_SELECT 0x2F //9600 baud
  
   #define PRG_RDB( addr )   __LPM((unsigned
   short)(addr))
   #define BV(bit) (1  (bit))
  
   /* UART global variables */
  
   volatile u08   RxChar;
   volatile int i = 0;
  
   /* UART Transmit Complete Interrupt Function */
   SIGNAL(SIG_UART0_TRANS)
   {
outp(0x43,UDR0);
   }
  
  
   /* UART Receive 

Re: [avr-gcc-list] Global variables and ISRs ???

[Parthasaradhi Nayani]

Hello Vincent,

To be able to modify/access a variable in interrupt,
declare it as volatile. Secondly, to test your code,
turn off optimization (s=0) in your make file. There
is a problem in your code also - you are not making
flag=0 after you send back the character. HTH.

Nayani


--- Vincent Trouilliez
[EMAIL PROTECTED] wrote:

 Hi gents,
 
 
 After the highly technical thread that just ended
 today, I would like to
 pick your brains on something much lower flying so
 to speak, sorry for
 that ! ;-)
 
 
 Problem : on my ATmega32, after several experiments
 (only just started
 using it, learning...), I am suffering a big
 problem. It seems that when
 I declare a variable as global, then modify it
 within an interrupt
 routine, the 'main' function can't see that the
 variable has been
 modified, as if it weren't a global variable...
 hmmm.
 
 The concrete case at hand, was that I tried to
 implement a buffer for
 incoming data on the UART. The ISR would fill the
 buffer and update the
 buffer pointer accordingly. The program in 'main'
 was checking to see if
 the pointer was non-zero and if yes, would send
 characters back to the
 serial port for me to see/check.
 I proved that all was working fine, interrupts etc,
 but somehow, 'main'
 would always see the buffer pointer as zero (hence
 would never react),
 as if the ISR didn't update it. 
 
 I simplified the program as much as I could, and the
 problem is still
 there. Could anyone have a look at the code below ??
 
 It receives characters on the serial port, toggle sa
 LED to prove that
 the ISR did get serviced, and sets flag to try and
 communicate with the
 'main' function which fails. 'main' never sees
 the flag as
 set :-/ Any help welcome, because I started
 scratching my head an
 hour ago, and now I don't have many hair left to
 pull !! ;-)
 
 
 Regards,
 
 
 --
 Vince, extremely annoyed...
 
 
 
 #include avr/io.h
 #include avr/interrupt.h
 #include avr/signal.h
 
 
 unsigned char flag, bin;  //global variables
 
 
 void ioinit (void){
 
   DDRD = 0x20;//PD5 as output for the LED
   PORTD = 0x00;   //turn LED off at boot.
   //set up USART
   UBRRH = 0x00;
   UBRRL = 12; //Baud Rate = 9600
   UCSRA = 0x02;   //mode asynchrone, fast clock
   UCSRC = 0X86;   //asynchronous, no parity, one stop
 bit, 8 data bits
   UCSRB = 0x98;   //transmitter and receiver enabled,
 interrupts on
 receiver
   flag = 0;   
   sei();
 }
 
 SIGNAL (SIG_UART_RECV){
 
   bin = UDR; //read incoming character to clear
 interrupt
   PORTD = ~PORTD; //toggle LED to prove ISR was
 serviced  
   flag = 1; //tell 'main' about the event
 }
 
 
 int main (void){
 
   ioinit ();
   while(1){
   if (flag){
   UDR = 'A';  //print a character to prove that the
 flag was set.
   }
   }
 }
 
 
 
 
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Re: [avr-gcc-list] Syntax : how to specifiy a binary constant ?

[Parthasaradhi Nayani]

Hello,

GCC 3.4.3 must work for

foo = 0b;
 OR
foo = 0B;

Are you getting compilation errors?

Nayani


--- Vincent wrote:
 
 I tried for example 
 
 foo = 0b;
 
 or 
 
 foo = b;
 
 but neither worked...
 
 
 I am using gcc-avr 3.4.3 and avr-libc 1.2.3
 
 
 Regards,
 
 
 --
 Vince


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Re: [avr-gcc-list] very simple program

[Parthasaradhi Nayani]

Hello,

In order to set the bit, you need to logical OR the
bit.

DDRB |= _BV (PB0);

to clear it

DDRB = ~_BV(PB0);


Nayani

  4: undefined reference to `__stack'
 

 
  #include avr/io.h
 
  int
  main(void){
   while (1) {
 DDRB = _BV(PB0);
 };
  }
 




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[avr-gcc-list] startup file

[Parthasaradhi Nayani]

Hello all,

I have written a very simple bootloader and it is
working OK. I would like to eliminate the intial
interrupt vectors to get more flash space. To achieve
this I would like to assemble the crtx file. I am not
sure if this is the right approach, and therefore
seeking your suggestions. Not withstanding the above
need I would like to get a copy of the source and also
would like to know the steps involved in assembling
this file. Thank you.

Regards
Nayani



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Re: [avr-gcc-list] startup file

[Parthasaradhi Nayani]

Hello Bernd Trog,

--- Bernd Trog [EMAIL PROTECTED] wrote:

 
 Have you tried to remove *(.vectors) from the
 linker script?

Thanks for the reply. I was not sure if one could
remove vector table from being linked. I am under the
impression that vector table is a part and parcel of
the startup file! Can you please post the exact linker
script to eliminate vector table? Thank you very much.

Regards
Nayani






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Re: [avr-gcc-list] (Newbie)2.Delay function not working as required

[Parthasaradhi Nayani]

Hello,  What is the code for delayms function? If you have a doubt that  optimisation is causing a problem, you could disable  optimisation, recompile and check the output (delay time).Regards  Nayani  Sumeet Pal Singh [EMAIL PROTECTED] wrote:  Hi  We tried to put delay in our program but it is not that reliable,  When we do  for(char i=0x00;i100;i++)  delayms(100);The output which we get is not 100*100ms but something unexpected. The  variable i is not used anywhere else in program. Is it that the  optimisation is causing problem, if yes please tell how to remive it.Thanks  Sumeet  ___AVR-GCC-list mailing
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[avr-gcc-list] sprintf problem

[Parthasaradhi Nayani]

Hello all,  In one of my projects (ATMega128 based) I am using floating point  numbers and sprintf to write a formatted record to a buffer. Tthe  buffer contents is then sent to a mini printer. The first two records  print properly and thereafter I am getting garbage from sprintf!! The  optimisation was set to 0. When I change the optimisation to s, then  correct data is being printed!! Moreover there is a difference in the  way _delay_loop_2 and _delay_loop_1 delays are generated with different  optimisations. I would like to know the reason why this is happening  (specially with sprintf) to avoid any pitfalls in my coding. Thanks in  advance.Nayani P
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Re: [avr-gcc-list] Makefile Changes

[Parthasaradhi Nayani]

Hello Sumeet,If you do not make changes to the source, then why compile again? If you do make changes, WinAvr will compile.RegardsNayaniSumeet Pal Singh [EMAIL PROTECTED] wrote:Can someone suggest some way(part of code of Makefile to change) to make avr-gcc to compile irrespective of whether the source file has been modified on not. I am not good in shell scripting. ThanksSumeet 
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[avr-gcc-list] Is this what we get for trying to help?

[Parthasaradhi Nayani]

Dear all,I have been following this list for more than a year to learn GCC  better and offer suggestions as and when felt that I was capable of  offering a comment to any of the posts. Though I was not posting any  replies in the recent past, I had been folowing the topics. I had  posted some questions earlier and they appeared in this list but  surprisingly my replies to this list are not appearing ant threfore, I  have included the personal mail id of Mr. Joerg Wunsch.Recently I saw a post and replied to it and got the following reply  from the sender. I sent my reply with an intension of helping the  student, but please see the mail I received. I copy paste the contents  for your perusal.  hello ,   1 . i want to tell you that the connections can be changed ifu get the working code .   2 . i want to tell you that the program
 can be modifiedaccording to our own needs .   3 . Dont try to become oversmart . People other than you have theexperience of writing a code .   4 . Avoid sending your stupid replies in case you dont have theanswer to what the user asked for .   5 . The only conclusion is that you are idiot .Have fun with your own replies you idiot  Ankur Handa  On Fri, 13 Oct 2006, Parthasaradhi Nayani wrote: Hello, How can you use working code of one board (whose connections may be   different from yours) on your board? All you need to know is the   initialisation sequence and writing commands/data. Is you LCD connected in 8   bit mode or 4 bit mode? Check the following link
 for example code. www.lampex.com Best wishes   Nayani P   Ankur [EMAIL PROTECTED] wrote:   Hello everyone ,   I am new to this mailing list . I need a favour from you . If   anyone has a working code for LCD interfaced to ATmega8 , can   you send it to me . I am really in a great need of this . Whatever   i wrote is not working properly . Thanks in advance   Ankur Handa   ___   AVR-GCC-list mailing list   AVR-GCC-list@nongnu.org   http://lists.nongnu.org/mailman/listinfo/avr-gcc-list  Thank you all.Regards  Nayani P 
	
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Re: [avr-gcc-list] Is this what we get for trying to help?

[Parthasaradhi Nayani]

Dear Mr. David,Thanks a lot for the mail and from now on I will remember to "reply all" rather than just "reply". Your words about the student are very apt and as you rightly said SMS-speak must be out. Thanks once again.RegardsNayaniDavid Brown [EMAIL PROTECTED] wrote: Hi Nayani,The reason your replies don't appear on the list is that this mailing list is set up so that replies are sent to the poster, not the list.  I can't remember why it is setup this way, but I remember there was a discussion about it a long time ago.  The list moderators and organisers had good reasons for having the list this way - and if Joerg and the others find the list faster or easier this way, then fair enough.  The trick for most email clients is to click "Reply All" rather than just "Reply",
 and adjust the addresses as desired.Regarding the obnoxious student - you just have to ignore such people. It's an unfortunate fact of mailing list (or Usenet) life.  On a moderated list like this, they are less of a problem, but there seem to be steadily more students (and, more depressingly, "professionals") who think others should do their work for them, and have no respect or manners.  Keep your flame-proof underwear on when posting, and filter out any posts where "you" is spelt "u", or where the poster can't find the shift key (there is nothing wrong with spelling mistakes or grammatical errors - but SMS-speak is right out).Best regards,DavidParthasaradhi Nayani wrote: Dear all,  I have been following this list for more than a year to learn GCC better  and offer suggestions as and when felt that I was capable of offering a  comment to any of the posts. Though I
 was not posting any replies in the  recent past, I had been folowing the topics. I had posted some questions  earlier and they appeared in this list but surprisingly my replies to  this list are not appearing ant threfore, I have included the personal  mail id of Mr. Joerg Wunsch.  Recently I saw a post and replied to it and got the following reply from  the sender. I sent my reply with an intension of helping the student,  but please see the mail I received. I copy paste the contents for your  perusal.   hello ,  1 . i want to tell you that the connections can be changed if  u get the working code .  2 . i want to tell you that the program can be modified  according to our own needs .  3 . Dont try to become oversmart . People other than you have the  experience of writing a code  . 
 4 . Avoid sending your stupid replies in case you dont have the  answer to what the user asked for .  5 . The only conclusion is that you are idiot .  Have fun with your own replies you idiot Ankur Handa   On Fri, 13 Oct 2006, Parthasaradhi Nayani wrote:Hello, How can you use working code of one board (whose connections may be different from yours) on your board? All you need to know is the initialisation sequence and writing commands/data. Is you LCD connected  in 8 bit mode or 4 bit mode? Check the following link for example code. www.lampex.com Best wishes   Nayani P   Ankur <[EMAIL PROTECTED]> wrote:   Hello everyone ,I am new to this mailing list . I need a favour
 from you . Ifanyone has a working code for LCD interfaced to ATmega8 , canyou send it to me . I am really in a great need of this . Whateveri wrote is not working properly . Thanks in advance   Ankur Handa   ___   AVR-GCC-list mailing list   AVR-GCC-list@nongnu.org   http://lists.nongnu.org/mailman/listinfo/avr-gcc-list  Thank you all.  Regards Nayani P  
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Re: [avr-gcc-list] bootloader for hex file on SD/MMC card

[Parthasaradhi Nayani]

Hello Abhijit,

I'm a student working with ATMEGA 8, 16 and 32, making autonomous robots for 
college contests and projects. I'm looking for a bootloader that will search 
for an SD/MMC card, find a hex file on it and program itself. This will make it 
quite easy to make hassle-free code changes or upgrades on contest venues, 
especially so because i can use any pc to load compiled hex files into the 
memory card..

I doubt if any one can give you a ready made bootloader. Since SD/MMC cards are 
normally connected to SPI bus, you could write the bootloader to read some 
specific memory locations on the card (through SPI) for some sort of signature 
and if present read and program the flash. 

Nayani


 
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Re: [avr-gcc-list] if test ignored?

[Parthasaradhi Nayani]

Rick Mann [EMAIL PROTECTED] wrote: On an AVR ATmega128:

I have two source files. In Serial.c, I define a global:
char sCommandReceived;

in the corresponding Serial.h file, I have:

extern char sCommandReceived;

sCommandReceived is set to 1 when enough bytes have been copied into  
a buffer from the serial port. In main.c, which includes Serial.h, I  
have:

 while (true)
 {
  if (sCommandReceived)
  {
   parseCommand();
  }
 }

One probable cause could be 'sCommandReceived' not declared as volatile if it 
is being accessed in the interrupt

Nayani

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RE: [avr-gcc-list] Mega2561 compilation problem

[Parthasaradhi Nayani]

Hello Stu Bell,
Thanks for your suggestions, but the code compiled using atman AVR is the same 
code we compiled using WinAvr. Surprisingly the code compiled using WinAvr 
resets the controller whereas code from Atman does not. We are not using any 
special SP initialization etc. We are using the default startup files of 
WinAvr. Thank you.

Regards
Nayani


Stu Bell [EMAIL PROTECTED] wrote:v\:* {behavior:url(#default#VML);} 
o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape 
{behavior:url(#default#VML);} st1\:*{behavior:url(#default#ieooui) }
   Your usage of stack will go up with the 2561, since a subroutine return 
address is now 3 bytes instead of 2.  Be sure that you properly account for 
that in any stack initialization that you do, and in all code that may use RAM.
Best regards, 
  Stu Bell 
 DataPlay (DPHI, Inc.) 
  
  
-
  
  From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Parthasaradhi 
Nayani
 Sent: Wednesday, June 06, 2007 6:07 AM
 To: avr-gcc-list@nongnu.org
 Subject: [avr-gcc-list] Mega2561 compilation problem
  
   
  Hello all,
 We were using a Mega128 in one of our boards and we had to shift to Mega2561 
as the requirement for program memory increased with advanced functional 
demands. We used Atman AVR demo and the code worked without a hitch. However 
when we use new (latest) WinAvr, the controller is resetting at one point or 
the other. We are using many sprintf_P functions to save RAM memory. Any clues, 
suggestions in helping us solve the problem will be highly appreciated. Thank 
you.
 
 Regards
 Nayani P


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[avr-gcc-list] Assembly language help

[Parthasaradhi Nayani]

Hello Group,

I am writing an assembly language function in which I need to get the address 
of a sub-routine into a register pair. How can I do it? A sample code is given 
below.

;--

.section .text
.global func1


func1:   nop
nop   ; some code
; at this point I would like to get the address of label1 into, say r24 and r25


label1:nop
 nop  ; some code
;-

I am using Mega64. Thanks in advance for help rendered.

Regards
Nayani P

   
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Re: [avr-gcc-list] Assembly language help

[Parthasaradhi Nayani]

Hello Greg,

Thanks a lot. I am now able to get the address. 

Regards
Nayani P

Gre7g Luterman [EMAIL PROTECTED] wrote: --- Parthasaradhi Nayani 

wrote:

 Hello Group,
 
 I am writing an assembly language function in which
 I need to get the address of a sub-routine into a
 register pair. How can I do it? A sample code is
 given below.

func1:
nop
nop
ldi   r24, lo8(label1)
ldi   r25, hi8(label1)
asr   r25   ; convert byte addr
ror   r24   ; to word addr
nop
nop

label1:
nop
nop

HTH,
Gre7g


   
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Re: [avr-gcc-list] Assembly language help

[Parthasaradhi Nayani]

Hello Erik,

Erik Christiansen [EMAIL PROTECTED] wrote:
http://opensource.cqu.edu.au/cgi-bin/info/info2html.cgi?(as.info)AVR-Modifiers
 
Thanks for the link. This will many people who use assembly language.

Few are interested in writing complete assembler programs on the AVR, it
seems, though there is some use of gcc's in-line assembler.

Perhaps yes, but at some point or the other one is forced to switch to 
assembly!!

A good document on AVR GCC covering all the aspects will go a long way in 
helping, not only beginners but also experienced programmers as reference book. 

As mentioned in my earlier mail, I did come across LO and HI, but now I can't 
get them. Any throw light on this  please?

Regards
Nayani P



   
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Re: [avr-gcc-list] Reading eeprom without using routines in eeprom.h, causes reset.

[Parthasaradhi Nayani]

Hello,
I tested the code on mega8 using winavr release 20070525. No problems were 
encountered.

NPS

Michael [EMAIL PROTECTED] wrote:  Hi, when I was new to the 
avr-gcc (and still fairly new to C), I read the eeprom like this:
   
  unsigned char eeread(unsigned char address)
  {
  while(EECR  _BV(EEWE));
  EEAR = address;
  EECR |= _BV(EERE);
  return EEDR; 
  }
   
  Not the ideal way of doing it, but it worked fine. I moved my code over from 
my debian system to winavr, which had a later version of the compiler.
   
  The above code now causes the device to reset. I have experienced this on an 
Atmega128, and an Atmega8.
   
  I can get things working again simply by using the eeprom.h routines in 
avr-libc, but I believe the above code should still work!
  I currently have the latest version of winavr, I don’t remember which 
compiler version I was running under debian.
   
  Can anybody shed any light on this? Why would the above code cause a reset 
when it used to work?
   
   
  Regards, Michael.
   
  
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Re: [avr-gcc-list] Fine Tuning code timings

[Parthasaradhi Nayani]

Hi Alex,
I am not sure why you are capturing the timer1 value, unless you are using the 
timer for other purposes as well. If not then the easiest method is to:

1. Enable time over flow interrupt.
2. Load the timer withe the required delay for the chosen baud rate. The port 
pin can be made low here itself as the start bit.
3. When the timer over flow occurs, send the bit and re-load the timer with the 
earlier value (so the interrupt will occur at the same time for the next bit)

If your baud rate is high (19,200 or more) then it makes sense to use an 8 bit 
timer as the higher byte of a 16 bit timer may have to be 0xff.

One rough method to get the timing s to pulse the port pin and monitor it on a 
scope and adjust the timer re-load value. When stop bit is sent, you may stop 
the timer to prevent unnecessary interrupts eating into processor time. Hope 
this helps.

Partha



Alex Shepherd [EMAIL PROTECTED] wrote: Hi Guys,

I'm trying to fine tune some C code timing issues for a software UART
written in AVRGCC.

Essentially when I go to transmit a byte, I capture the value of Timer1, set
the output compare value to the current timer value + the bit period,
activate the Tx pin and then wait for the interrupt handler to output the
rest of the bits in the byte.

The problem I'm having is that the latency between the timer interrupt
firing and the code in the interrupt handler that drives the pin state is
causing some error. I need some way to calculate the amount of time to
reduce the initial timer period by so that the pin state driving logic in
the interrupt handler executes at the right time. 

What I would like to try and find out (and why I'm asking on this list):

Is there any way to figure out using compiler tricks/magic how far into a
function or interrupt handler a line of code is so that I can use this
offset value to tune the initial start-bit timer value. The subsequent bit
timings are ok as they are generated using the same code path?

I have experimented using LABELS in the code and trying to do pointer
arithmetic but they don't seem to be accessible outside the function or I
was just doing it wrong. 

Merry Christmas

Alex Shepherd



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[avr-gcc-list] Binding a register pair to a pointer

[Parthasaradhi Nayani]

Hello all,
I have a time critical application where I have to process an external 
interrupt request. When the interrupt occurs, I have to read a port and store 
this data pointed by a pointer. In order to reduce the time taken by pushes and 
pops, I would like to bind a register pair to a char pointer. My search for 
examples has not yielded any results. I have tried something like unsigned 
char *ptr asm (x) but this is throwing out an error. Can some one show me an 
example on how to achieve this? Thank you.


Nayani P



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RE: [avr-gcc-list] Binding a register pair to a pointer

[Parthasaradhi Nayani]

Hello Weddington,
Thanks for the mail, but the FAQ example is as follows:

register unsigned char counter asm (r3)

The above is an example for a single byte value, but I would like to bind a 
pointer which is a 16 bit value and perhaps the X register may be used. I tried 
using constraints also but the complier complains. An example line of code on 
how to do this will be highly appreciated. Thank you.

Regards
Nayani

--- On Wed, 12/10/08, Weddington, Eric [EMAIL PROTECTED] wrote:
From: Weddington, Eric [EMAIL PROTECTED]
Subject: RE: [avr-gcc-list] Binding a register pair to a pointer
To: [EMAIL PROTECTED], avr-gcc-list@nongnu.org
Date: Wednesday, December 10, 2008, 12:45 AM

 
This is describe in the avr-libc user manual, in the FAQ. 



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RE: [avr-gcc-list] On getting an ISR leaner with GCC

[Parthasaradhi Nayani]

 
 If you look in the avr-libc manual under Frequently Asked 
 Questions you can find FAQ #3: How to permanently bind a 
 variable to a register.
 That allows you to assign particular registers to variables, 
 although care must be used when using the avr-libc library functions.


I had faced a similar situation and some time ago I posted a query
for a similar problem. The manual mentions a single register 
binding and in some cases a pointer may (two registers)
may be required for binding and the manual does not talk about
such binding. Now that this topic is being discussed, I was wondering if 
I can solve my problem!! Thank you.

P. Nayani







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Re: [avr-gcc-list] Failing to share a flag between two files/modules :-/

[Parthasaradhi Nayani]

Hello,
I guess there are two variables named flag being created, one in main and the 
other in ui.c. Please define the global variable in one .C file of your choice 
and tell the other file by using extern directive. Hope this solves your 
problem

Nayani



--- On Sun, 2/8/09, Vincent Trouilliez vincent.trouill...@modulonet.fr wrote:
From: Vincent Trouilliez vincent.trouill...@modulonet.fr
Subject: [avr-gcc-list] Failing to share a flag between two files/modules :-/
To: avr-gcc-list@nongnu.org avr-gcc-list@nongnu.org
Date: Sunday, February 8, 2009, 2:02 PM

Hello Gents,

I am having problem communicating between main.c and another
file/module, ui.c to name it.

In main.c I set a flag from a timer ISR, every 100ms. 
In ui.c I am watching for that flag, but unfortunately it always
reads zero :-/ However if I watch for the flag in main() then it works
fine.

I am watching the flag in ui.c, so I declared it in ui.h, then ui.h
gets included in main.c so I can set the flag from there. 
Well that was my reasoning, but doesn't quite work sadly !

I must be doing something wrong obviously, just would love to learn what
it is ! ;-)


Regards,

--
Vince, a bit stuck and wondering again...


ui.h
---
static volatile uint8_t flag;



ui.c


if( flag )
{
   flag = 0;
   /* Do some stuff */
}



main.c

#include ui.h

ISR (TIMER0_COMP_vect)
{
flag = 1;
}

main() {}


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Re: [avr-gcc-list] How to force GCC to not to remove nop statements ?

[Parthasaradhi Nayani]

Hi Vincent,
If I understand correctly, the word volatile itself is to tell the compiler 
not to ignore the statement. I am not sure if your statement is correct, but I 
have used

 asm volatile (nop::);

and the compiler never removed the nops from code. 

Nayani

--- On Thu, 2/19/09, Vincent Trouilliez vincent.trouill...@modulonet.fr wrote:
From: Vincent Trouilliez vincent.trouill...@modulonet.fr
Subject: [avr-gcc-list] How to force GCC to not to remove nop statements ?
To: avr-gcc-list@nongnu.org avr-gcc-list@nongnu.org
Date: Thursday, February 19, 2009, 11:31 PM

Hi list,

Like many people I guess, I am using in-lined nop asm statements to
respect the timing of external devices, when toggling their control
lines.

In the case at hand I am driving a text LCD module, and the 
Enable line must be pulsed low for 250ns.

void lcd_send_nibble(uint8_t data)
{
...
//pulse Enable line
LCD_PORT |= LCD_E;
__asm__ volatile(nop);
__asm__ volatile(nop);
__asm__ volatile(nop);
__asm__ volatile(nop);
LCD_PORT = ~LCD_E;

}


My AVR was running at 8MHz, so an instruction cycle of 125ns, so two nop
in-lined were spot on, just perfect, and it ran fine.

Today I pushed the AVR (ATmega32) up to its maximum of 16MHz.
So I now need 4 nops not two. So I did that.. and the LCD doesn't work
reliably. Suspecting the problem, I went straight to the generated
assembly, and horror, my 4 nop statements have disappeared !

I made a few trials. It appears that up to and including 3 nop
statements, GCC leaves them alone. But if I put 4 of them, it removes
them all ! 

Any way to instruct GCC to leave my 4 nops ?

Am using avr-gcc 4.3.2


Regards,

--
Vince


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[avr-gcc-list] introducing a new section in data memory

[Parthasaradhi Nayani]

Hello all,
I needed to create a buffer of 256 bytes starting at a page boundary (xx00) in 
the RAM memory (Mega8). 

I added this line in the makefile

LDFLAGs = -wl,--section-start=.test=0x800200

and defined a variable in the .C file (shown below)

unsigned char mem3 __attribute__ ((section(.test)));

However variable mem3 is being assigned address 0x60 in the controller???

also if I define another global in next line to mem3 I get error that .data and 
.bss overlap lma 0xa0?? 

I am of the opinion that all variable defined with attribute .test will be 
located in that memory area and all other global variables will be located in 
their native memory. Perhaps if I ma able locate the .test section properly the 
overlap error may vanish. Can you correct the problem please? Thank you.


Nayani




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[avr-gcc-list] introducing a new section in data memory

[Parthasaradhi Nayani]

Hello all,

I sent a mail on the subject but it seems to have got lost   and therefore 
posting again

I need to have a buffer of about 256 bytes starting at a page boundary in the 
ram of Mega8. To get this I introduced a new section and assigned it an address 
in makefile. I defined variables, to test, using attribute section. However 
when I try to debug the code I see the variables are allotted memory locations 
other than specified in the section? 

My makefile has the following statement

LDFLAGs = -wl,--section-start=.test=0x800100

My .C file has the following statements

unsigned char mem3 __attribute__ ((section(.test)));
int mem5 __attribute__ ((section(.test)));

I have also noticed, if I declare a global variable I get overlap error. Please 
help me solve this problem. Thank you.


Nayani



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RE: [avr-gcc-list] introducing a new section in data memory

[Parthasaradhi Nayani]

--- On Fri, 2/20/09, Weddington, Eric ewedding...@cso.atmel.com wrote:
First off, is that a typo above? It's suppose to be an uppercase
'W' like so:
LDFLAGs = -Wl,--section-start=.test=0x800200

It was a typo. Will test and reply. Thank you for your time. 

Regards
Nayani




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RE: [avr-gcc-list] introducing a new section in data memory

[Parthasaradhi Nayani]

First off, is that a typo above? It's suppose to be an uppercase
'W' like so:
LDFLAGs = -Wl,--section-start=.test=0x800200

Hi,

Checked the 'W' and it was indeed capital letter only. The problem persists!! 
Any more suggestions please? Thank you.

Nayani






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Re: [avr-gcc-list] introducing a new section in data memory

[Parthasaradhi Nayani]

--- On Sat, 2/21/09, Georg-Johann Lay a...@gjlay.de wrote:

 
 The trouble might return if .data/.bss will grow and then
 overlap(s)

No sir, I needed 256 bytes buffers two and the other variables may total to 
about 10 or so.

 The problem is that you cannot
 introduce holes in a section, i.e. start with .data, reserve
 a hole of 0x100 (or put .stuff in it) and then proceed with
 .data. Therefore, there may be a waste of RAM of up to 0xff
 bytes.

If .data and .test are two adjacent sections, I guess there will be no issue 
(well they need not be adjacent for that matter). If my .test section starts at 
a page boundary, it is enough.

 The only safe way to do this is
 -- supplying own linker script that introduces alignment as
 needed.
 -- supplying own linker script that introduces sections
 .data.lo at
0x60, .test at 0x100, .data.hi at 0x200. But depending
 on the
size of .data, you will have to split .bss instead and
 explicitely
say that has to go in the .data fragments. Not nice.
 -- or allocate 0x1ff bytes and compute the effective
 address at runtime.
But then you must access indirect through a pointer.
 -- Maybe it's best to take the space from the top of
 RAM. Then you will
waste just 0x60 bytes (or can put some other stuff
 there), and you
can use direct addressing if you prefer or need that.
 Yust init the
stach pointer to an other value by means of -minit-stack
 from command
line or simply by __builtin_alloca (0x160) resp. auto
 char
test_buffer[0x160] upon entering main().
 
  Just realize that because your variable is now in the
 .test section, don't expect the toolchain to
 automatically initialize the variable to zeros in the
 future. 

Thank you for the clue. I will take care to init the section myself.

It may do that now, but the toolchain will change to
 not include the __do_clear_bss if it detects that there is
 nothing in the .bss section. The variable is now outside the
 .bss, so there are no guarantees that it will be initialized
 to a known value (zeros) in the startup code.
 
 This can be fixed by renaming the section to .bss.test, as
 far as you refer to
 http://lists.gnu.org/archive/html/avr-gcc-list/2009-01/msg00162.html
 But note that the linker assumes one monolithic section,
 and resp. does
 the code in __do_clear_bss resp. __do_copy_data!
 
 Also nothe that there are some bugs in the patch cited
 above.
 I will fix them as soon I will find the time for it.
 
 By the way, what is the specification for the handling of
 orphans?
 Seems as if they are assumed to be adopted by .data?


Regards
Nayani



  


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RE: [avr-gcc-list] introducing a new section in data memory

[Parthasaradhi Nayani]

--- On Sat, 2/21/09, Weddington, Eric ewedding...@cso.atmel.com wrote:

  It works for me.
  
  See attached demo. After the build look at the .map
 file and 
  the disassembly file (.dis).
  
  Just realize that because your variable is now in the
 .test 
 Attachment error. Trying again for the list.


Thank you very much. Will compile, check and revert.

Regards
Nayani
 



  


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Re: [avr-gcc-list] How to tell avr-gcc not to use some registers in the whole program?

[Parthasaradhi Nayani]

--- On Sun, 2/22/09, Georg-Johann Lay a...@gjlay.de wrote:
 You can do this by introducing two global register
 variables like
 
 register foo_t * pfoo asm (r2);
 
 
 Also note the command line option -ffixed-2 -ffixed-3 that
 turn R2/R3 into fixed registers (in contrast to R2/R3 beeing
 call-saved-regs, which is the default for them).
 
 Also note that you most probably won't experience the
 desired reduction of program memory and/or execution time.
 This is because the compiler must move R2 to X, Y, or Z to
 access a location.
 
 Making Y or Z global regs will crash the compiler sooner or
 later. I would not recommend to make X global, either.
 
 

In your sample code above only R2 (8 bit) is bound to the variable. I had a 
similar requirement for using 16 bit (say X register) as pointer, can you post 
a sample line of code on how to do this? Thank you.

Nayani



  


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Re: [avr-gcc-list] Re: C vs. assembly performance

[Parthasaradhi Nayani]

 From: Nicholas Vinen h...@x256.org

 For example, things like unsigned char x, y;
 x = y4 could
 use the nibble swap instruction rather than four shifts,
 and things like

Shifting a byte or int right or left must push in 00s from the other side so 
swapping a nibble is not the right thing to do. So is the case with other 
examples. Correct me if I am wrong.

Nayani


  


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Re: [avr-gcc-list] when is it safe to use -mtiny-stack

[Parthasaradhi Nayani]

 The -mtiny-stack may (and should) be used only for devices
 with 0xFF max RAM adderss, i.e. if SP register is 8-bit.
 All devices with 1KB and 2KB FLASH memory satisfy this
 condition, now.

Hello all,
If the memory size itself is 256 Bytes, naturally SP will be 8 bits and where 
is the need to explicitly tell the compiler of mini-stack? Is it to generate 
any stack over flow errors? Thank you.

Regards
Nayani


  


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Re: [avr-gcc-list] PN problem

[Parthasaradhi Nayani]

 Hi everybody,
 I am using Winavr for some years and now I started having
 problems with PN recently. When I start PN and open a
 project and don't open any source files, commands like
 clean, make all etc., work. But when I open a source file
 and try the same commands, I get no rule to make error.
 Where could the problem be and how can rectify it? Thank you
 for your time and help.
 

Since nobody replied to my post, I am wondering if I am making a stupid mistake 
which does not require a reply? OR am I the only person to face this problem?

Nayani P


  


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RE: [avr-gcc-list] PN problem

[Parthasaradhi Nayani]

 From: Weddington, Eric eric.wedding...@atmel.com
 Subject: RE: [avr-gcc-list] PN problem
 I don't deal much with PN projects. But I would suspect
 something within the .pnps file. IIRC, this file is XML.
 Perhaps there is some path issue written in the project
 file...

Hi,
Thank you very much for the reply. I had another copy of PN2 installed and I 
think this was causing the problem. I uninstalled this copy and tried using the 
one that came with WinAvr. This seems to work, provided the Makefile is in the 
source directory.

Best regards
Nayani P



  


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[avr-gcc-list] Storing variables in external memory - suggestions

[Parthasaradhi Nayani]

Hello all,
I was wondering if any one can suggest a decent method of automatically 
assigning address space to variables in external EEPROM. For internal EEPROM 
the attribute EEMEM will allocate addresses in sequence. One can insert or 
delete a variable and the address space gets adjusted properly. Is there a 
method of doing something similar for external EEPROM. I have an external 
EEPROM where I would like to store and retrieve variables. Thanks in advance 
for your suggestions.

Regards
Nayani P




  


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Re: [avr-gcc-list] Storing variables in external memory - suggestions

[Parthasaradhi Nayani]

--- On Fri, 5/22/09, David Kelly dke...@hiwaay.net wrote:

 All EEMEM does is this in eeprom.h:
 
 #define EEMEM __attribute__((section(.eeprom)))
 
 AVR Studio convention is that internal .eeprom starts at
 0x0081. So
 what I'd do if I were you and wanted the compiler to assign
 static
 memory addresses in an external eeprom would be:
 
 #define    EEEXT
 __attribute__((section(.eeexternal)))
 
 Then in my Makefile (or somewhere in AVR Studio) would add
 this to the
 linker definitions (am not certain 0x00a1 is
 available):
 
 LDFLAGS+=--section-start=.eeprom=00a1
 
 
 If you put initialized definitions in EEEXT they will be
 lost. Your
 code has to write them in the external device because
 neither the
 compiler nor AVR Studio knows how. You can add a rule to
 the Makefile
 (if you are using make) to write a hex file containing your
 external
 EEPROM initial values:
 
 %_eeext.hex: %.elf
     avr-objcopy -j .eeexternal
 --change-section-lma .eeexternal=0 -O ihex $ $@
 
 
 Then you need a target such as this which will invoke the
 above rule
 (think it needs a blank line after):
 
 object_eeext.hex:
 
 
 Finally, believe it goes without saying that you have to
 provide
 routines to access your external EEPROM device.

Hello David Kelly,

Thanks a lot for the suggestions. Yes, I understand that initializing the 
variables will not actually save the vales into the memory locations. I will 
try a sample code and revert. Thanks once again.

B Regards
Nayani P






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Re: [avr-gcc-list] Storing variables in external memory - suggestions

[Parthasaradhi Nayani]

 --- On Fri, 5/22/09, David Kelly dke...@hiwaay.net
 wrote:
  AVR Studio convention is that internal .eeprom starts
 at 0x0081. So what I'd do if I were you and wanted the compiler to
 assign static memory addresses in an external eeprom would be:
  
  #define    EEEXT
  __attribute__((section(.eeexternal)))
  
  am not certain 0x00a1 is available.
  
  LDFLAGS+=--section-start=.eeprom=00a1
  

Hello David Kelly,
I tried as you mentioned and seems to work fine. One more question is, how to 
know the address ranges used by WinAVR? so one can use the unused ranges for 
external EEPROM, FLASH etc. Thank you.

Regards
Nayani P








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[avr-gcc-list] Memory problem

[Parthasaradhi Nayani]

Hello all,
I have interfaced flash memory to my mega64 and created a section for this 
memory. I have some variables and two structures which are located in this 
memory. Initially I defined the variables first and then the structure. After 
linking I checked the map and list files and found that the first defined 
variable occupied the first memory location and so on. Later I moved the 
structure to the top and compiled again but this time the variables remained in 
the same old order (the structure should have occupied the first byte onwards). 
Why is this happening? If I need to put some variables in some fixed address in 
this memory how can I do it? Thanks in advance for your help.

Regards,
Parthasaradhi
Hyderabad



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Re: [avr-gcc-list] Memory problem

[Parthasaradhi Nayani]

--- On Mon, 6/22/09, David Kelly dke...@hiwaay.net wrote:

Study the include files for register definitions for a means of
controlling the absolute address of allocation.


Thank you David Kelly for your response. I will sieve through the header files 
to know how to allocate a variable to a memory location.

Regards,
Parthasaradhi
Hyderabad






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Re: [avr-gcc-list] Memory problem

[Parthasaradhi Nayani]

--- On Tue, 6/23/09, Joerg Wunsch j...@uriah.heep.sax.de wrote:

The only method to not have the linker reorder your variables is to
just use a single variable (per memory section).  So, put some kind of
an embracing struct around all your variables you'd like to have in
a particular order, and you'll be done.

Thank you very much for your suggestion. In case I declare all the variables in 
a structure then accessing each variable will require using the structure 
name.variable name! However I would like to assign a memory to a variable also 
therefore can you suggest how I can do this? Thanks once again for your support.

Regards,
Nayani P





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Re: [avr-gcc-list] Memory problem

[Parthasaradhi Nayani]

--- On Tue, 6/23/09, David Kelly dke...@hiwaay.net wrote:

Something like this might work for you:

typedef struct {
    uint8_t variable;
    uint16_t a, b, c, d;
    uint32_t e;
} FLASH_STRUCT;

#define flash_p ((FLASH_STRUCT *)(0x8000))


Hello David Kelly,

Thanks a lot for taking time to enlighten me on these issues. As you
had suggested to one of my earlier posts,  I created a section and named it 
EXFLASH and put my
variables there, many of them strings. I had a horrid time trying to
find out why a structure defined thus



struct EXFLASH mystruct tempstruct;



had some weird values.  When I checked the map file the named structure
was allotted space in RAM!! Finally I changed the above to



struct mystruct EXFLASH tempstruct;



and the structure was allotted space in EXFLASH. Phew!!! I finally got the 
struct into FLASH (this will help others in future I guess)

I created one more in RAM and copied the FLASH content to this stuct and able 
to access members witout difficulty. Any pointers on fixed memory allocation 
will really help. Thanks once again to you and Joerg.



Regards,
Nayani P







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[avr-gcc-list] no rule to make elf - error

[Parthasaradhi Nayani]

Hello all,
I am using avr-gcc (WinAVR 20090313) 4.3.2 with PN - version v2.0.8.718-basie. 
When I create a project and try to compile a very simple file, I am getting 

make.exe: *** No rule to make target `test.c.elf', needed by `elf'.  Stop.

Can some one point ahy I am getting this help? I have created the project using 
the PN File-new-project etc. I created and stored the Makefile in the project 
duirectory using Mfile. Thanks for your support.

Nayani P




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[avr-gcc-list] Xmega support

[Parthasaradhi Nayani]

Hello all,
I have just started testing an XMEGA64 chip and I find a peculiar problem when 
I use sprintf. Following are the environment/specs:

XMEGA64 running at 32MHz (using the internal freq generator)
USART on PC0, operating at 115K BAUD.
One timer in port D being used in compare capture mode.

The program is a very simple one. At start, 8000H, (let me call this CCAVAL) is 
written into the compare register and this generates a frequency on pin OC0A. 
Usart receive is interrupt driven. When a new value for CCAVAL is sent through 
the serial port, main loop converts the value and writes to the compare 
register. This should change the frequency of the square wave on OC0A. To test 
the vaule being written to ccaval is being sent back to PC and this is where 
the peculiar problem is noticed. We are using sprintf function to conver the 
binary value of ccaval and then sending it PC through another function. When 
we use a global buffer in sprintf, the program behaves erratically. The timer 
stops for some time and then starts with the new value. However if use a local 
buffer in sprintf then everything works fine. Example code given below

char globalbuf[20];

sprintf (globalbuf,%05u\r\n,ccaval);  // problem. globalbuf defined outside 
main.

sprintf (localbuf,%05u\r\n, ccaval); // no problem. everything works fine.

Can some one point me to the mistake we are making? or is this a problem with 
GCC? Thank you.

Regards
Nayani P












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Re: [avr-gcc-list] Xmega support

[Parthasaradhi Nayani]

Hello All,
Just not to enter a wrong address, I copy the address or clear the message and 
write new one. My apologies for inadvertently doing so. I am creating a new 
thread with a different heading. Thanks.

Nayani




--- On Thu, 8/20/09, David Kelly dke...@hiwaay.net wrote:

From: David Kelly dke...@hiwaay.net
Subject: Re: [avr-gcc-list] Xmega support
To: Steven Michalske smichal...@gmail.com
Cc: avr-gcc-list avr-gcc-list@nongnu.org
Date: Thursday, August 20, 2009, 3:11 AM

On Wed, Aug 19, 2009 at 02:23:10PM -0700, Steven Michalske wrote:
 This message got buried in a thread, because you used a reply to a  
 previous message from the list.
 
 It's poor manners to hijack threads, and can cause some users not to  
 reply.

Same applies to top-post without trim.

-- 
David Kelly N4HHE, dke...@hiwaay.net

Whom computers would destroy, they must first drive mad.


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[avr-gcc-list] XMEAG64 code problem

[Parthasaradhi Nayani]

Hello All,
I am facing a peculiar problem with XMEGA64 code. When I use a global buffer in 
sprintf, the board appears to reset, but the initial values (which are changed 
before a call to sprintf) are not getting effected. If I use a local buffer 
(same size) there is no problem. Can some one point out what could be wrong? 
Thanks.

Nayani





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[avr-gcc-list] Larger than 64K memory sections

[Parthasaradhi Nayani]

Hello all,
I am using a 4MB flash memory with my Mega64. I would like to create a memory 
section for the entire 4MB. Is it possible? If yes, how can this be done in the 
makefile? Thank you very much for your time.

Regards,
Nayani




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[avr-gcc-list] Problem allocating memory in xflash

[Parthasaradhi Nayani]

Hello all,
I have created an external flash memory section in the makefile thus

LDFLAGS += -Wl,--section-start,.exflash=0x85

and named (defined) this section as XFLASH. 

I have a structure prclkp of size 32 bytes. When I define 

struct prclkp XFLASH PLULOC1[1023];   No error is reported, whereas 

struct prclkp XFLASH PLULOC1[1024]; generates an error - size of array too 
large

If the size of the section is 64K, then the above i well within the limit but 
still the error is popping up. Has this anything to do with sign? Please 
advice. Thank you.


Regards,
Nayani




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Re: [avr-gcc-list] Re: Larger than 64K memory sections

[Parthasaradhi Nayani]

David Kelly wrote:
You are right that we know nothing about the application in question - details 
here would make it much easier to give recommendations. 

Hello all,

I mentioned 4MB flash as it is the HW spec. This 4MB gets filled over a period 
of time.

Details of application - I have data packets each 32 bytes in size and we have 
accommodate 2000 of these (predefined). This I plan to put in a part of the 4MB 
Flash. Rest of the memory will be used for storing records comprising of these 
data packets with data and time etc. The records will be deleted from time to 
time but the data packets will remain. It is possible to use a long int as an 
address pointer from the start of the available memory (after the data packets) 
and store records. I still curious to know how one can create a section larger 
than 64K. 

Nayani



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Re: [avr-gcc-list] Problem allocating memory in xflash

[Parthasaradhi Nayani]

From: Joerg Wunsch j...@uriah.heep.sax.de 

Sure, it depends from sizeof(int).

My array size is 32K bytes and the section is supposed to be 64K right? and is 
not the built-in limit of a section 64K? Thanks.

Regards
Nayani




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Re: [avr-gcc-list] Problem allocating memory in xflash

[Parthasaradhi Nayani]

From: Jan Waclawek konf...@efton.sk

Sure, it depends from sizeof(int).

Hummm, for me, the relationship is not quite sure. Can you explain that in 
more detail, please?

I tried to allocate  32K bytes of memory. I am not sure if this is a problem of 
user defined sections.

Nayani




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Re: [avr-gcc-list] Re: Larger than 64K memory sections

[Parthasaradhi Nayani]

From: David Kelly dke...@hiwaay.net

4 million bytes or bits? Most FLASH devices are sized by the bit.

It is 4M Bytes. 


No matter what you do you won't be able to say *MyUInt16Ptr = 0x1234;
you will have to write a routine and use it something like this:

u16_value = 0x1234;
result = Write4MBFlash( (uint32_t)MyUint16Ptr, sizeof(uint16_t), u16_value );

One advantage I found, using name spaces (sections) is, generating a hex file 
for initialised data, which can be downloaded through serial port.

All the external SPI FLASH devices I have used are paged. One
read/writes to a RAM buffer in the device then flush that buffer to a
page in FLASH. IIRC the Atmel device I last used had 264 byte pages
which served to complicate addressing if one insisted on using all 264
bytes. Believe the designer's intent was that one use 256 bytes as a
sector and the other 8 bytes for tracking usage, even linking to
previous sector and next sector for a form of filesystem.

Never thought of this (using the extra 8 bytes for tracking/linking to other 
sectors)

Atmel had a very useful appnote containing C routines for access to
their DataFlash parts which helped a lot. I felt the need to heavily
edit it for style and naming convention. Rearranged a bit, and deleted a
lot that I didn't use. But it was a very good start.

Will check Atmel's site . Thank you.

Nayani




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Re: [avr-gcc-list] including default eeprom values in flash memory

[Parthasaradhi Nayani]

From: Michael Clift mich...@clift.com.au

    Hi, I am using winavr, and would like to include the default eeprom values 
(normally output to .eep) in flash memory. I want to do this so that my 
application can easily default the eeprom. 

Hello,
EEPROM data in FLASH memory? then the easy way is to use the PGM space 
attribute to the variables you want in flash.

Nayani




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Re: [avr-gcc-list] PLease help wtih a correct code

[Parthasaradhi Nayani]

--- On Sun, 2/28/10, Jeano Kalawa doki...@yahoo.fr wrote:
From: Jeano Kalawa doki...@yahoo.fr
 
I am working with my final prosject at University. I work with a SHT  75 
sensirion sensor to measure temperature and humidity. I use an ATmega 32 
controller and have to send data to a PC-skjerme via UART. I do try to use the 
sample code from sensirion ,but it does not work.

Hello Jeano,
Seen the PDF. The code looks mangled!!! Initial comment says the code is for 
8051 but includes show at89s53.h. Again intrins.h is not part of GCC.

Nayani




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[avr-gcc-list] Peculiar code size problem

[Parthasaradhi Nayani]

Hi all,
I am working on an ATMEGA8. Since my code was getting close to 8K, I thought I 
would tweak the code. I have a function listed below

void pulse_en (void)
{
  set_EN; // Set EN
  _delay_loop_1 (255);
  clr_EN; // clear EN
 _delay_loop_1 (255);
}
Since the delay after the clr instruction had no meaning, I commented the 
line and compiled the code hoping I would save a couple of bytes. But to my 
surprise the code size increased to 7172 bytes compared to 7148 bytes with the 
function call in place. I looked at the list file and found that the function 
gets shifted to a different location with and without the function call. Here 
are the list file snippets

With the call in place:

351               pulse_en:
 352               .LFB23:
 353               .LM47:
 354               /* prologue: function */
 355               /* frame size = 0 */
 356               .LM48:
 357 0128 C29A      sbi 56-32,2
 358               .LBB80:
 359               .LBB81:
 360               .LM49:
 361 012a 8FEF      ldi r24,lo8(-1)
 362 012c 982F      mov r25,r24
 363               .LVL17:
 364               /* #APP */
 365                ;  83 
c:/winavr-20100110/lib/gcc/../../avr/include/util/delay_basic.h 1
 366 012e 9A95      1: dec r25
 367 0130 01F4      brne 1b
 368                ;  0  2
 369               /* #NOAPP */
 370               .LBE81:
 371               .LBE80:
 372               .LM50:
 373 0132 C298      cbi 56-32,2
 374               .LBB82:
 375               .LBB83:
 376               .LM51:
 377               /* #APP */
 378                ;  83 
c:/winavr-20100110/lib/gcc/../../avr/include/util/delay_basic.h 1
 379 0134 8A95      1: dec r24
 380 0136 01F4      brne 1b
 381                ;  0  2
 382               .LVL18:
 383               /* epilogue start */
 384               /* #NOAPP */
 385               .LBE83:
 386               .LBE82:
 387               .LM52:
 388 0138 0895      ret

Without the call:
621               .LFE21:
 623               .globalpulse_en
 625               pulse_en:
 626               .LFB23:
 627               .LM87:
 628               /* prologue: function */
 629               /* frame size = 0 */
 630               .LM88:
 631 01c2 C29A      sbi 56-32,2
 632               .LBB146:
 633               .LBB147:
 634               .LM89:
 635 01c4 8FEF      ldi r24,lo8(-1)
 636               .LVL36:
 637               /* #APP */
 638                ;  83 
c:/winavr-20100110/lib/gcc/../../avr/include/util/delay_basic.h 1
 639 01c6 8A95      1: dec r24
 640 01c8 01F4      brne 1b
 641                ;  0  2
 642               /* #NOAPP */
 643               .LBE147:
 644               .LBE146:
 645               .LM90:
 646 01ca C298      cbi 56-32,2
 647               /* epilogue start */
 648               .LM91:
 649 01cc 0895      ret


Will some one please let me know why this is happening? If such is the case, 
perhaps extra code is being generated for other function too. 
I am using: avr-gcc (WinAVR 20100110) 4.3.3
 
Thank you for your time.

Regards,
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Re: [avr-gcc-list] Peculiar code size problem

[Parthasaradhi Nayani]

Dear Eric,
Yes indeed, the total code bloated, though the function size actually reduced. 
Perhaps my first post was not clear on this point. I can mail you the entire 
code, should you wish to see it. Please let me know so I can do the needful. I 
am wondering as to what this cause is and any method to detect it or at the 
least prevent code bloat. Thank you for your time.
 
Regards,
Nayani





 From: Weddington, Eric eric.wedding...@atmel.com
 Sent: Monday, March 19, 2012 1:44 AM
Subject: RE: [avr-gcc-list] Peculiar code size problem
 

Your function pulse_en reduced in size as expected. However, your
overall code size increased.

Without access to the rest of your code, we cannot tell what causes the
overall size increase.

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Re: [avr-gcc-list] Peculiar code size problem

[Parthasaradhi Nayani]

Hello David,
Thank you for your reply. Yes this seem to be the problem Current working 
program with delay call size turned out to be 7092 bytes. With your suggestion 
of noinlie attribute the code is now 7086 bytes. Thank you for your help. 
This seems to have solved the problem and also answered my query. This may also 
help others who have similar problem. Thanks once again.
 
Regards,
Nayani




 From: David A. Lyons dly...@lyons42.com
To: Parthasaradhi Nayani partha_nay...@yahoo.com 
Cc: avr-gcc-list@nongnu.org avr-gcc-list@nongnu.org 
Sent: Monday, March 19, 2012 5:46 AM
Subject: Re: [avr-gcc-list] Peculiar code size problem
 
The smaller size might be making the compiler decide to inline the function at 
some call sites where it didn't before.  You could experiment with 
-fno-inline-small-functions (compiler option) and/or 
__attribute__((noinline)) on your function declaration:

    void pulse_en (void) __attribute__((noinline));

    void pulse_en (void)
    {
        ...
    }

Cheers,

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[avr-gcc-list] Parm to application

[Parthasaradhi Nayani]

Hello all,
I have a boot loader and an application on a Mega168. As boot loader and 
application are two different entities, is there any way the boot loader can 
pass a parameter to application code? Would like something like main (int argc, 
char *argv[]). Any suggestions please? Thank you.
 
Regards,
Nayani
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Re: [avr-gcc-list] Parm to application

[Parthasaradhi Nayani]

From: Georg-Johann Lay a...@gjlay.de


Reserve a piece of RAM that does not depend on how the application
is compiled, for example at the start of .data (bump .data to a later
location) or at the top of the stack (initialize SP to RAMEND-offset).

In the boot loader, write the data to that reserved space.

It should also be okay to call main from .init8 by hand if
you prefer C, e.g.

  main (argc, argv);
  _exit (0);
or
  main (argc, argv, env);
  _exit (0);


Hello Johann,
Thank you for your reply. Yes this was one approach that is possible, but it is 
pretty much dependent on absolute address. Passing arguments to main is 
actually not possible in a bare bone system right? or is there any method?I 
would actually prefer to call application main with parameters from boot 
section.

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Re: [avr-gcc-list] Parm to application

[Parthasaradhi Nayani]

From: Georg-Johann Lay a...@gjlay.de


With
  int x __attribute__((section (.bootdata)));
you can use x in the known way, it's only about locating .bootdata
to whatever location you deem appropriate.  Read the linker manual.

This appears to be the only best way!!! This means I create a section, say 
.bootdata with some
address in the boot loader. Create exactly the same section with the same 
address in the actual application
section. Since the boot loader starts first, it writes whatever data to be 
passed into this section and
when application gets executed, it reads this section. Am I right?

One point to consider - boot loader is somewhat a permanent fixture in flash, 
whereas application(s)
can keep changing or updated. Should the compiler version be same for both? 
will the ordering of variables change
with versions? If this remains same, then the above approach is best as of now, 
else the same compiler
has to be used for future updates of application.

 I would actually prefer to call application main with parameters
 from boot section.

Calling main from boot does not sound sane.  How do you know the
address of main?  How do you run startup code to initialize .data
and .bss, setup SP, call constructors, etc.?  How do you reset the
hardware like communication I/O?

There are two issues -
1. I/Os can be initialized in the boot section as the boot loader will be 
specific to the target board. 
2. SP setup etc., will have to be done afresh in the application portion. When 
I mentioned calling main, it is
actually calling application startup (00 address). This is not possible any way 
(I guess).

Thank you.

Regards
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[avr-gcc-list] External 256K FLASH - memory pointer

[Parthasaradhi Nayani]

Hello all,
I have an external FLASH (serial) of size 256K. I would like to create a memory 
section for this memory and have pointers (more than 16 bits) to this memory. 
Can some one help me please?  I am sorry if such a topic has already been dealt 
with, as my googling did not yield the desired result(s). I await your 
suggestions/help and thank you for your time.

 
Regards,
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Re: [avr-gcc-list] External 256K FLASH - memory pointer

[Parthasaradhi Nayani]

From: Joerg Wunsch j...@uriah.heep.sax.de
To: avr-gcc-list@nongnu.org 
Sent: Tuesday, September 18, 2012 11:21 AM

What's the point?  A pointer is just a 32-bit (or perhaps 24-bit,
in recent AVR-GCC versions) number.

Normally, the point of using a pointer is that the compiler arranges
for you to dereference the pointer automatically, but this memory
being external, not accessible by normal CPU instructions, this cannot
work anyway.  Consequently, you can use the respective integer numbers
by itself (perhaps through some kind of typedef that hints them being
memory addresses).

Thanks for the response. Basically the requirement is to use external serial 
FLASH memory. We wanted large pointer for two things
1. To declare a section and assign variable names which is better than using 
absolute addresses. This is possible.
2. Pass the address to functions which do the reading and writing the memory. 
Given below is an example function prototype we would like to have

void ReadXFlashBlock (unsigned char *destptr, unsigned char *sourceaddr, 
unsigned int noofbytes);

In the above destptr is not an issue but sourceaddr is. If a 32 bit pointer can 
be somehow declared then this will be pretty elegant. If this is not possible 
then the only alternative would be to change the function parameters as shown 
below which is not really elegant.

void ReadXFlashBlock (unsigned char *destptr, long sourceaddr, unsigned int 
noofbytes);
The calling program must treat this long variable as a pointer rather than long 
itself.

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Re: [avr-gcc-list] External 256K FLASH - memory pointer

[Parthasaradhi Nayani]

Hello Richard,
Thanks a lot for your suggestion.

Yes we can and it has already been suggested: Define Your own abstract data 
type with an underlying 32 bit integer. You can even overload all operators 
for it to achieve full pointer semantics. But I would not go so far and 
overload the dereferencing operator for readability reasons. The signature for 
Your read function would then look like:

void ReadXFlashBlock (unsigned char* dst, FlashAddress src, unsigned int size);

If templates are Your friends, You can go further and add the value type to 
Your abstract address type.

This way You avoid ugly casting orgies everywhere in Your code and You can not 
mess up integers, internal memory pointers and external flash addresses. Ok, 
these are features of avr-g++, but why not?

I do not know if there will be any code over head due to C++. Unfortunately my 
forte is 'C'. Can I trouble you for some examples/sample code please? Thank you 
once again.

Regards
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Re: [avr-gcc-list] avr-gcc 4.7 for Windows

[Parthasaradhi Nayani]

From:Georg-Johann Lay g...@gcc.gnu.org

To: avr-gcc-list@nongnu.org 
Subject: [avr-gcc-list] avr-gcc 4.7 for Windows
 
GCC 4.7 has just been released, and I decided to provide a MinGW32 build of
avr-gcc-4.7.2.

Many people feel uncomfortable with building the tools to run under MS Windows,
so here they are.

The package is supplied as a ZIP archive avr-gcc-4.7.2-mingw32.zip.

Unpack the ZIP file to your favorite a location; it will inflate to a directory
called avr-gcc-4.7.2-mingw32.

The binaries are located in avr-gcc-4.7.2-mingw32\bin

To use the compiler, call avr-gcc-4.7.2-mingw32\bin\avr-gcc.exe directly or add
the avr-gcc-4.7.2-mingw32\bin to your PATH environment variable.

Most notable changes in 4.7.2 compared to 4.7.1 is the support of a new
configure option --with-avrlibc that implements a better integration of
AVR-Libc with avr-gcc: AVR-Libc supplies optimized versions of support
functions that traditionally live in libgcc.  --with-avrlibc makes sure that
always the optimized versions from AVR-Libc are used.

Hi,
Thanks for the post. I noticed some peculiarities in the latest version 
specially regard to FLASH section. The compiler is throwing out errors when 
PROGMEM attribute is provided. 


unsigned char PROGMEM P_gu8_nlup[]


dvr.c:205:40: error: variable 'P_gu8_nlup' must be const in order to be put 
into read-only section by means of '__attribute__((progmem))'


The error clears if 'const' is placed before 'PROGMEM'. 

unsigned char const PROGMEM P_gu8_nlup[]


Wondering whether there is any change in the latest version. Thank you.

Nayani
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Re: [avr-gcc-list] gcc-avr 4.9.2 -Os messes with interrupt vectors

[Parthasaradhi Nayani]

Hi,
"I do *not* want the ISR to be called". I guess you do not want the interrupt 
to be enabled. If you do not start the timer (as the interrupt is timer 
related) this interrupt will never occur. If you are using the timer for 
something else and need the timer running, then you need not explicitly enable 
timer overflow interrupt (see TIMSK register bits). In the while loop, you are 
always setting the port bit which I guess is connected to the LED and the LED 
will glow when this bit is 1. Suggest toggling the LED through a while loop 
with delays (large enough to be able to see LED flashing) inserted. Regards,
Parthasaradhi
Hyderabad
 

On Sunday, May 8, 2016 3:06 PM, "a...@tuta.io"  wrote:
 

 Thank you for your instant response.

I am sorry if I was unclear about that: I do *not* want the ISR to be called. 
The LED should turn on because I enable it in main(), however, the uC goes 
straight to the ISR!

For example, if I set the LED to high in the ISR and set it to low in main(), 
it will be set to high and the LED will turn on when I flash it. Even though I 
used cli()!

This behavior appears to depend on -Os, so I guess I am either using the tools 
incorrectly, or there is a bug in the optimization code.

8. Mai 2016 11:22 von partha_nay...@yahoo.com:


First off, you are disabling global interrupts (cli ()). You need to enable 
them (sei ()). I presume you are toggling the LED in ISR, if so the LED will 
not toggle as interrupts are disabled.  Regards,
Parthasaradhi
Hyderabad
 

On Sunday, May 8, 2016 2:40 PM, "a...@tuta.io"  wrote:
 

  Hello,

I have been working on a project for some time and at some point, everything 
just stopped working. It appears that as soon as I include an ISR in my C code, 
the main function won't even be called anymore. I reduced my code to this:


#include 
#include 

int main (void) {
  cli();
  DDRB = 0xff;
  while(1) PORTB |= (1 << PB5);
  return 0;
}

ISR(TIMER0_OVF_vect) {}

But the LED just won't turn on. The strange thing is: If I remove the ISR at 
the bottom without changing anything else, even keeping the include, everything 
works. If I remove the -Os option from gcc but keep the ISR, everything works.

I use these commands to compile, link and flash it:

F_CPU=1600L
avr-gcc -Wall -DF_CPU=$F_CPU -c -mmcu=atmega168 -Os main.c -o main.o
avr-ld -mavr5 -o led-test.elf main.o
avr-objcopy -O ihex led-test.elf led-test.hex
sudo avrdude -c avrisp2 -p atmega168 -P usb -b 57600 -U flash:w:led-test.hex


I am quite new to the avr tools so I might just have made a silly mistake, so I 
would appreciate any tips!
Thank you!


LSB:
Distributor ID: Ubuntu
Description:    Ubuntu 16.04 LTS
Release:    16.04
Codename:   xenial

Output of avr-gcc -v:
Using built-in specs.
Reading specs from /usr/lib/gcc/avr/4.9.2/device-specs/specs-avr2
COLLECT_GCC=avr-gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/avr/4.9.2/lto-wrapper
Target: avr
Configured with: ../src/configure -v --enable-languages=c,c++ --prefix=/usr/lib 
--infodir=/usr/share/info --mandir=/usr/share/man --bindir=/usr/bin 
--libexecdir=/usr/lib --libdir=/usr/lib --enable-shared --with-system-zlib 
--enable-long-long --enable-nls --without-included-gettext --disable-libssp 
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=avr CFLAGS='-g -O2 
-fstack-protector-strong -Wformat ' CPPFLAGS=-D_FORTIFY_SOURCE=2 CXXFLAGS='-g 
-O2 -fstack-protector-strong -Wformat ' FCFLAGS='-g -O2 
-fstack-protector-strong' FFLAGS='-g -O2 -fstack-protector-strong' GCJFLAGS='-g 
-O2 -fstack-protector-strong' LDFLAGS='-Wl,-Bsymbolic-functions -Wl,-z,relro' 
OBJCFLAGS='-g -O2 -fstack-protector-strong -Wformat ' OBJCXXFLAGS='-g -O2 
-fstack-protector-strong -Wformat '
Thread model: single
gcc version 4.9.2 (GCC)
 
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