Re: [fpc-pascal] How to build for arm6 in RaspberryPi on arm7?
On Tue, 8 Sep 2020 20:09:53 +0200, Jonas Maebe via fpc-pascal wrote: >On 08/09/2020 16:13, Bo Berglund via fpc-pascal wrote: >> This happened also after I ran a Run/CleanUpAndBuild operation, so >> clearly there is something I am missing here. > >Is your FPC installation itself also built for ARMv6? (rtl and packages) > No, it is on an RPi4 so it is ArmV7. I hoped the compiler could be set to use one instruction set or the other depending on this project setting. I could presumably build another FPC 3.0.4 using the ArmV6 setting even though I am on an Armv7 system, right? But the result has to go somewhere else. Or replace the previous one. When doing a make install where would 3.0.4V6 go then? And what about the ~/.fpc,cfg where all of the settings for fpc are stored, can it be the same for both v6 and v7 compilers? And finally, how to set Lazarus to use the v6 compiler rather than the v7? Or maybe I have to compile fpc for V6 even though I am on V7 and thereafter only build ArmV6 compatible applications? Probably also Lazarus itself needs to be recompiled to V6 because unless that is done there will be problems when it recompiles itself after package installations... Especially if FPC has been replaced by a V6 version. -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] String literals and code page of .pas source file
Mattias Gaertner via fpc-pascal schrieb
am Di., 8. Sep. 2020, 22:32:
> On Tue, 8 Sep 2020 20:27:20 +0200
> Jonas Maebe via fpc-pascal wrote:
>
> > On 07/09/2020 08:51, LacaK via fpc-pascal wrote:
> >
> > > attached simple Lazarus compilable project (one Form).
> > >
> > > ...
> > > type
> > > String1250 = type AnsiString(1250);
> > >
> > > const
> > > c2: AnsiString = 'áéíóčž';
> > > c3: WideString = 'áéíóčž';
> > > c4: String1250 = 'áéíóčž';
> > >
> > > { TForm1 }
> > >
> > > procedure TForm1.FormShow(Sender: TObject);
> > > begin
> > > label1.Caption:='áéíóčž'; // FAIL
> > > label2.Caption:=c2; // FAIL
>
> label2.Caption:='a'+c2; // OK
>
> > > label3.Caption:=c3; // OK
> > > label4.Caption:=c4; // FAIL
> > > end;
>
> Reason is that LCL TLabel.Caption expects UTF-8.
> You can use
>
> label2.Caption:=WinCPToUTF8(c2); // from unit LazUTF8
>
> Maybe SetCaption could check if passed string is not CP_ACP and do a
> conversion.
>
Why does c4 fail however? Shouldn't the compiler insert a type conversion
from codepage 1250 to CP_ACP which is UTF-8 in Lazarus?
Regards,
Sven
>
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Re: [fpc-pascal] TFPObjectlist example
James Richters via fpc-pascal schrieb am Di., 8. Sep. 2020, 20:07: > What’s the difference between TList and TFPGList? Which one is better > for this example? > The main difference is that TFPGList ist a generic, thus when you specialize it with your record you'll have a typesafe object where you don't need to manually work with pointers while for TList you either need to work with pointers or declare a descendant with typesafe setters/getters like you had done in the other mail. You could also take a look at the generic TList in Generics.Collections which does not require an = operator like TFPGList does. Please note that if you work with TFPGList or the Generics.Collection.TList then you need to modify an entry using a local variable if your entries are records: entry := mylist[i]; entry.field := entry.field * 2; mylist[i] := entry; This is because the getter for the Items property will provide a /copy/ of the entry. With Classes.TList you'd use a pointer however and thus you can modify it in place. Regards, Sven > ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] String literals and code page of .pas source file
On Tue, 8 Sep 2020 20:27:20 +0200
Jonas Maebe via fpc-pascal wrote:
> On 07/09/2020 08:51, LacaK via fpc-pascal wrote:
>
> > attached simple Lazarus compilable project (one Form).
> >
> > ...
> > type
> > String1250 = type AnsiString(1250);
> >
> > const
> > c2: AnsiString = 'áéíóčž';
> > c3: WideString = 'áéíóčž';
> > c4: String1250 = 'áéíóčž';
> >
> > { TForm1 }
> >
> > procedure TForm1.FormShow(Sender: TObject);
> > begin
> > label1.Caption:='áéíóčž'; // FAIL
> > label2.Caption:=c2; // FAIL
label2.Caption:='a'+c2; // OK
> > label3.Caption:=c3; // OK
> > label4.Caption:=c4; // FAIL
> > end;
Reason is that LCL TLabel.Caption expects UTF-8.
You can use
label2.Caption:=WinCPToUTF8(c2); // from unit LazUTF8
Maybe SetCaption could check if passed string is not CP_ACP and do a
conversion.
Mattias
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[fpc-pascal] How to implement a circular buffer object in pascal?
I would like to create a buffer into which a thread can push incoming data and the main thread can extract it for processing. Data are coming from the serial port in a worker thread and should be consumed by the main thread. The data is a byte stream. Are there any good examples available? I have only implemented such systems in C on embedded platforms so it is not pascal enough to easily port. -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal Quoted from: http://free-pascal-general.1045716.n5.nabble.com/How-to-implement-a-circular-buffer-object-in-pascal-tp5736027.html Bo, Send me your email address here v...@golden.net Brian _ Sent from http://free-pascal-general.1045716.n5.nabble.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Ethernet Relays
On Tue, 8 Sep 2020, James Richters via fpc-pascal wrote:
Yes 10 was too short, I made it larger and larger until it worked. 1000 was
the lowest value that worked so I set it to 2000, that's still quite a bit
faster than the default.
If I make a mistake in the link but the server IP address is correct, I get a
valid connection but then it fails and terminates with:
An unhandled exception occurred at $000100017675:
EHTTPClient: Unexpected response status code: 401
If I use the wrong IP address, but that IP address has a different server
running on it, but that page is not available, I get:
An unhandled exception occurred at $000100017675:
EHTTPClient: Unexpected response status code: 401
Is there a way to obtain these errors as well so it doesn't terminate my
program?
Yes, catch the EHTTPClient exception just as you catch the ESocketError:
try
S:=TFPHTTPCLIENT.SIMPLEGET('http://10.10.01.01/3/15');
except
On E: ESocketError do
Writeln('Could not connect to server: ',E.Message);
On EH : EHTTPClient do
begin
Writeln('Error getting the document : '+EH.Message);
end;
end;
If you created a TFPHTTPClient instance you can also examine the
ResponseStatusCode property, it will contain the server response code.
Michael.
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Re: [fpc-pascal] String literals and code page of .pas source file
On 07/09/2020 08:51, LacaK via fpc-pascal wrote:
> attached simple Lazarus compilable project (one Form).
>
> ...
> type
> String1250 = type AnsiString(1250);
>
> const
> c2: AnsiString = 'áéíóčž';
> c3: WideString = 'áéíóčž';
> c4: String1250 = 'áéíóčž';
>
> { TForm1 }
>
> procedure TForm1.FormShow(Sender: TObject);
> begin
> label1.Caption:='áéíóčž'; // FAIL
> label2.Caption:=c2; // FAIL
> label3.Caption:=c3; // OK
> label4.Caption:=c4; // FAIL
> end;
The attached pure FPC-variant of your project works fine with FPC 3.2.0
for me (except for the very first writeln, because that one gets
interpreted as "writeln(shortstring)"), so it may be Lazarus-specific.
Best ask it on the Lazarus list or post it on their bug tracker instead.
Also make sure you did *not* build your Lazarus with -dDisableUTF8RTL
Jonas
{$IFDEF FPC}
{$mode objfpc}
{$h+}
{$CODEPAGE cp1250}
{$ENDIF}
{$H+}
{$ifdef unix}
uses
cwstring;
{$endif}
type
String1250 = type AnsiString(1250);
const
c2: AnsiString = 'áéíóè';
c3: WideString = 'áéíóè';
c4: String1250 = 'áéíóè';
var
r: rawbytestring;
s: ansistring;
begin
DefaultSystemCodePage:=cp_utf8;
writeln('áéíóè');
writeln(c2);
writeln(c3);
writeln(c4);
r:='áéíóè';
writeln(r);
r:=c2;
writeln(r);
r:=c3;
writeln(r);
r:=c4;
writeln(r);
s:='áéíóè';
writeln(s);
s:=c2;
writeln(s);
s:=c3;
writeln(s);
s:=c4;
writeln(s);
end.
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Re: [fpc-pascal] How to implement a circular buffer object in pascal?
>Bo, > >Most of the users on this forum have never interfaced with hardware , as you >can see from the responses. Those who have interfaced with hardware have >developed circular buffers which they know work , and they reuse them again >and again. I did this about 10 years ago when working on a PIC project with serial data coming in from sensors and such, using Ansi-C. And the buffer was just an array of char (byte in pascal) and there was a read and a write index. The read index was only ever changed by the consumer and the write index by the interrupt routine when adding data. The data reception was done in the interrupt and the code stuffed the data into the array using ++ syntax for the index, with a check for overflowing the array and then setting the index back to zero. There was probably also an overrun detection and action if the consumer is not fast enough, but I do not remember now... > >The following assumes you are receiving data from a sender , and in this >case the sender and receiver are connected via 1Gbps Ethernet using Synapse >(works really well). > > >A thread receives data into an array of byte. RxBuffer : Array[0..1500] of >byte ... and copies the number of bytes received into a circular buffer , >which is an array of RxBuffer. This is where I lose you, are you saying the circular buffer is not individual bytes but something larger? What is the size of RxBuffer? Looks like it is an array of byte, can you then make an array of such arrays? ... The CicBuffer is an array of N RxBuffer , which is an array of byte. The main loop extracts the byte array and either decodes them or type casts them into a record structure if it is compatible with the contents of the byte array, Type RxBufferType = array[0..1500] of byte; Var CirBuffer : array[0..N] of RxBufferType; > >In pseudo code it looks like this ... >CircularBuffer : Array[0..N] of RxBuffer >There is a ReadIndex and a WriteIndex , both longword or longint. > >The thread moves the data into the circular buffer continuously increase >the WriteIndex each write of RxBuffer data. If the WriteIndex > N then >WriteIndex := 0 , otherwise it is increased by 1. > >The main loop (below) moves the byte data using MOVE from CircBuffer to >whatever structure it represents , increase the ReadIndex by one and decodes >the data as needed. Looks like an array of some bigger datatype then. But if so then one needs to be able to detect in the receiver that enough data has arrived to make one such object to put onto the next buffer... ... you appear to be thinking of a asynchronous serial (RS-232 / 422) with no delimiters to indicate when a complete message is received. ... think of the byte array as an Ethernet packet of any length data of which the data structure is known. This is received using Synapse (UDP in this case) and copied into RxBuffer byte array by a thread which is always running until the main program is shut down. Whenever the thread receives a "complete" packet from Synapse (it signals a complete packket) , the thread code then puts it into RxBuffer and then copies RxBuffer into CircBuffer[WriteIndex] and increments the WriteIndex. If the WriteIndex < N then WriteIndex := WriteIndex +1 else WriteIndex := 0 // wraps The ReadIndex is incremented similar to the WriteIndex, if ReadIndex < N then ReadIndex := ReadIndex +1 else ReadIndex := 0; The circular buffer can be made as large as you need to "absorb" incoming data while the main loop is busy doing something else. The "nice" aspect of a circular buffer is that if the main loop is very slow and the incoming data stream is very fast , the WriteIndex will eventually overrun the ReadIndex and data is lost but nothing chokes or crashes , and eventually the ReadIndex will catch up. BTW : There are enough things that can go wrong implementing a circular buffer , and while it should be possible (and very nice) to implement it as an object , it may not be worth the effort. At least get it working as non-object code , then decide. > > If ReadIndex <> WriteIndex then > .. do the work as described above and increment the ReadIndex > >I use the Free Pascal unit which allows suspending the thread while the >ReadIndex is being increased. In the old DOS/DPMI days we would disable >interrupts briefly. Do you use CriticalSection for this? No . .. I started to originally but found it wasn't necessary as it uses a semaphore to prevent a Write occurring when the ReadIndex is being incremented. The FPC unit syncobjs is used the create a semaphore which is RESET before incrementing the ReadIndex and SET immediately after. This prevents a potential race condition where data could be written to CircBuffer at the exact time the ReadIndex is being incremented. >If you are innterested I can send you code snippets showing exactly how to >implement the circular buffer. > BTW : The circular buffer approach can also be used when transmitting data. For example Synapse maintains its own transmit
Re: [fpc-pascal] How to build for arm6 in RaspberryPi on arm7?
On 08/09/2020 16:13, Bo Berglund via fpc-pascal wrote: > This happened also after I ran a Run/CleanUpAndBuild operation, so > clearly there is something I am missing here. Is your FPC installation itself also built for ARMv6? (rtl and packages) Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] TFPObjectlist example
What’s the difference between TList and TFPGList? Which one is better for this
example?
James
From: fpc-pascal On Behalf Of Vojtech
Cihák via fpc-pascal
Sent: Tuesday, September 8, 2020 10:29 AM
To: FPC-Pascal users discussions
Cc: Vojtěch Čihák
Subject: Re: [fpc-pascal] TFPObjectlist example
Hi,
some crippled formatting, so again:
However, in your case (records) I would rather use TFPGList from FGL unit:
1) add {$modeswitch ADVANCEDRECORDS}
2) add FGL to uses
3) define class operator =
test = record
Port :String;
Size :Byte;
Status :Word;
class operator = (A,B: test): Boolean;
End;
4) implement it
class operator test.=(A, B: test): Boolean;
begin
Result:=(A.Port=B.Port) and (A.Size=B.Size); // and ...
end;
5) define specialized list:
TMyL = specialize TFPGList;
6) create it
MyList: TMyL;
...
MyList:=TMyL.Create;
Now you can work with it comfortably
MyList[1].Port:='abc';
V.
__
> Od: "Vojtěch Čihák via fpc-pascal" >
> Komu: ja...@productionautomation.net
> , "FPC-Pascal users discussions" >
> Datum: 08.09.2020 16:21
> Předmět: Re: [fpc-pascal] TFPObjectlist example
>
__
> Od: "James Richters via fpc-pascal" >
> Komu: "'FPC-Pascal users discussions'" >
> Datum: 07.09.2020 01:08
> Předmět: [fpc-pascal] TFPObjectlist example
>
James
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Re: [fpc-pascal] Help with TList example
Thank you for the help, I'll give it a try!
James
-Original Message-
From: fpc-pascal On Behalf Of Jean
SUZINEAU via fpc-pascal
Sent: Tuesday, September 8, 2020 8:47 AM
To: fpc-pascal@lists.freepascal.org
Cc: Jean SUZINEAU
Subject: Re: [fpc-pascal] Help with TList example
Another way is to declare TMyRec as class instead of record.
In this case, you don't need the dereference operator ^ .
No need of new and dispose, just Create and Free, as for TMyRecList.
I don't know if there is a better performance when you use a record, but as far
as I know, record/object/new/dispose is just the old syntax for the first
object oriented programming born with Turbo Pascal 5.5 around 1989.
The new syntax with class / constructor Create / destructor Free is born Delphi
1 around 1995.
Below is your code modified with TMyRec=class
==
program Project1;
{$mode objfpc}{$H+}
uses
SysUtils, Classes;
type
TMyRec=class
Value: Integer;
AByte: Byte;
end;
TMyRecList=class(TList)
private
function Get(Index: Integer): TMyRec;
public
destructor Destroy; override;
function Add(Value: TMyRec): Integer;
property Items[Index: Integer]: TMyRec read Get; default;
end;
{ TMyRecList }
function TMyRecList.Add(Value: TMyRec): Integer; begin
Result := inherited Add(Value);
end;
destructor TMyRecList.Destroy;
var
i: Integer;
begin
for i := 0 to Count - 1 do
Items[i].Free;
inherited;
end;
function TMyRecList.Get(Index: Integer): TMyRec; begin
Result := TMyRec(inherited Get(Index)); end;
var
MyRecList: TMyRecList;
MyRec: TMyRec;
tmp: Integer;
begin
MyRecList := TMyRecList.Create;
for tmp := 0 to 9 do
begin
MyRec:= TMyRec.Create;
MyRec.Value := tmp;
MyRec.AByte := Byte(tmp);
MyRecList.Add(MyRec);
end;
for tmp := 0 to MyRecList.Count - 1 do
Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ', MyRecList[tmp].AByte);
WriteLn(' Press Enter to free the list');
ReadLn;
MyRecList.Free;
end.
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Re: [fpc-pascal] Ethernet Relays
Yes 10 was too short, I made it larger and larger until it worked. 1000 was
the lowest value that worked so I set it to 2000, that's still quite a bit
faster than the default.
If I make a mistake in the link but the server IP address is correct, I get a
valid connection but then it fails and terminates with:
An unhandled exception occurred at $000100017675:
EHTTPClient: Unexpected response status code: 401
If I use the wrong IP address, but that IP address has a different server
running on it, but that page is not available, I get:
An unhandled exception occurred at $000100017675:
EHTTPClient: Unexpected response status code: 401
Is there a way to obtain these errors as well so it doesn't terminate my
program?
James
-Original Message-
From: fpc-pascal On Behalf Of Michael
Van Canneyt via fpc-pascal
Sent: Tuesday, September 8, 2020 7:44 AM
To: James Richters ; FPC-Pascal users
discussions
Cc: Michael Van Canneyt
Subject: Re: [fpc-pascal] Ethernet Relays
On Tue, 8 Sep 2020, James Richters via fpc-pascal wrote:
> I added ssockets now I can compile it.
>
> I have this working with the ssockets unit added:
> Try
> S:=TFPHTTPCLIENT.SIMPLEGET('http://10.10.01.01/3/15');
> except
> On E: ESocketError do
> Writeln('Could not connect to server'); end;
>
> But when I try the version with the timeout, I always get the error.
> What is the proper way to get the page into a variable with the timeout
> method?
> I tried S:= C.Get('http://10.10.01.01/3/15'); But I'm not sure
> that's the right way to do it, but even without the S:= I always get
> the EsocketError
What timeout did you use ? 10 ms is probably too short.
Michael.
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Re: [fpc-pascal] How to implement a circular buffer object in pascal?
On Mon, 7 Sep 2020 14:45:31 -0700 (MST), Brian via fpc-pascal wrote: >Bo, > >Most of the users on this forum have never interfaced with hardware , as you >can see from the responses. Those who have interfaced with hardware have >developed circular buffers which they know work , and they reuse them again >and again. I did this about 10 years ago when working on a PIC project with serial data coming in from sensors and such, using Ansi-C. And the buffer was just an array of char (byte in pascal) and there was a read and a write index. The read index was only ever changed by the consumer and the write index by the interrupt routine when adding data. The data reception was done in the interrupt and the code stuffed the data into the array using ++ syntax for the index, with a check for overflowing the array and then setting the index back to zero. There was probably also an overrun detection and action if the consumer is not fast enough, but I do not remember now... > >The following assumes you are receiving data from a sender , and in this >case the sender and receiver are connected via 1Gbps Ethernet using Synapse >(works really well). > > >A thread receives data into an array of byte. RxBuffer : Array[0..1500] of >byte ... and copies the number of bytes received into a circular buffer , >which is an array of RxBuffer. This is where I lose you, are you saying the circular buffer is not individual bytes but something larger? What is the size of RxBuffer? Looks like it is an array of byte, can you then make an array of such arrays? > >In pseudo code it looks like this ... >CircularBuffer : Array[0..N] of RxBuffer >There is a ReadIndex and a WriteIndex , both longword or longint. > >The thread moves the data into the circular buffer continuously increase >the WriteIndex each write of RxBuffer data. If the WriteIndex > N then >WriteIndex := 0 , otherwise it is increased by 1. > >The main loop (below) moves the byte data using MOVE from CircBuffer to >whatever structure it represents , increase the ReadIndex by one and decodes >the data as needed. Looks like an array of some bigger datatype then. But if so then one needs to be able to detect in the receiver that enough data has arrived to make one such object to put onto the next buffer... > > If ReadIndex <> WriteIndex then > .. do the work as described above and increment the ReadIndex > >I use the Free Pascal unit which allows suspending the thread while the >ReadIndex is being increased. In the old DOS/DPMI days we would disable >interrupts briefly. Do you use CriticalSection for this? >If you are innterested I can send you code snippets showing exactly how to >implement the circular buffer. > Please do, thanks! -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] TFPObjectlist example
Hi,
some crippled formatting, so again:
However, in your case (records) I would rather use TFPGList from FGL unit:
1) add {$modeswitch ADVANCEDRECORDS}
2) add FGL to uses
3) define class operator =
test = record Port :String; Size :Byte; Status :Word; class
operator = (A,B: test): Boolean; End; 4) implement itclass operator test.=(A,
B: test): Boolean;begin Result:=(A.Port=B.Port) and (A.Size=B.Size); // and
...end; 5) define specialized list:
TMyL = specialize TFPGList;
6) create it
MyList: TMyL;
...
MyList:=TMyL.Create;
Now you can work with it comfortably
MyList[1].Port:='abc';
V.
__
Od: "Vojtěch Čihák via fpc-pascal"
Komu: ja...@productionautomation.net, "FPC-Pascal users discussions"
Datum: 08.09.2020 16:21
Předmět: Re: [fpc-pascal] TFPObjectlist example
__
> Od: "James Richters via fpc-pascal"
> Komu: "'FPC-Pascal users discussions'"
> Datum: 07.09.2020 01:08
> Předmět: [fpc-pascal] TFPObjectlist example
>
James
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Re: [fpc-pascal] Help with TList example
> On Sep 8, 2020, at 6:10 PM, James Richters via fpc-pascal > wrote: > > I'm trying to figure out how TList works. I found the code example below by > doing a search, but I can't compile it, I get Error: Illegal qualifier on > the line Do you want an array of pointers (objects allocated on the stack) or an array of records (i.e. one continuous block of memory? I you want an array of pointers try using classes as mentioned or if you want an array of records try TFPGList and specialize for your record type. Regards, Ryan Joseph ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] TFPObjectlist example
Hi,
I used TFPObjectList only once, for visual component TECAccordion
(https://wiki.lazarus.freepascal.org/Eye-Candy_Controls#TECAccordion). Each
item of list is derived from TWinControl so it is possible to use it even for
visual components (like TCollection).
However, in your case (records) I would rather use TFPGList from FGL unit:
1) add {$modeswitch ADVANCEDRECORDS}
2) add FGL to uses3) define class operator =test = record Port :String;
Size :Byte; Status :Word; class operator = (A,B: test): Boolean; End; 4)
implement itclass operator test.=(A, B: test): Boolean;begin
Result:=(A.Port=B.Port) and (A.Size=B.Size); // and ...end; 5) define
specialized list:
TMyL = specialize TFPGList;
6) create it
MyList: TMyL;
...
MyList:=TMyL.Create;
Now you can work with it comfortably
MyList[1].Port:='abc';
V.
__
Od: "James Richters via fpc-pascal"
Komu: "'FPC-Pascal users discussions'"
Datum: 07.09.2020 01:08
Předmět: [fpc-pascal] TFPObjectlist example
James
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Re: [fpc-pascal] How to build for arm6 in RaspberryPi on arm7?
On Tue, 08 Sep 2020 15:11:07 +0200, Bo Berglund via fpc-pascal wrote: >Is there some project setting I can activate in order to build for >*all* RPi devices by only using ARMv6 instructions? I used Project/ProjectOptions/ConfigAndTarget and: set Target CPU family = arm set Target processor = ARMV6 The project built fine on an RPi4B with 4GB RAM And it ran just fine on the dev RPi4 So I used scp to copy the executable over to an RPiZero and test it there. But I got an exception on this platform: pi@rpizero:~/Downloads $ ./SerialTest An unhandled exception occurred at $00031C44: EAccessViolation: Access violation $00031C44 This happened also after I ran a Run/CleanUpAndBuild operation, so clearly there is something I am missing here. -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] How to build for arm6 in RaspberryPi on arm7?
I am using RPi3 and RPi4 platforms when working on RPi projects with Lazarus 2.0.8 and Fpc 3.0.4. Now I realized that the binaries I create will probably not work on PiZero and RPi2 devices because these are Arm6 and the dev platform is Arm7. Is there some project setting I can activate in order to build for *all* RPi devices by only using ARMv6 instructions? I really do not want to work in the IDE on a PiZero or Pi2 because these are a bit slow... -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Help with TList example
Another way is to declare TMyRec as class instead of record.
In this case, you don't need the dereference operator ^ .
No need of new and dispose, just Create and Free, as for TMyRecList.
I don't know if there is a better performance when you use a record,
but as far as I know, record/object/new/dispose is just the old syntax
for the first object oriented programming born with Turbo Pascal 5.5
around 1989.
The new syntax with class / constructor Create / destructor Free is born
Delphi 1 around 1995.
Below is your code modified with TMyRec=class
==
program Project1;
{$mode objfpc}{$H+}
uses
SysUtils, Classes;
type
TMyRec=class
Value: Integer;
AByte: Byte;
end;
TMyRecList=class(TList)
private
function Get(Index: Integer): TMyRec;
public
destructor Destroy; override;
function Add(Value: TMyRec): Integer;
property Items[Index: Integer]: TMyRec read Get; default;
end;
{ TMyRecList }
function TMyRecList.Add(Value: TMyRec): Integer;
begin
Result := inherited Add(Value);
end;
destructor TMyRecList.Destroy;
var
i: Integer;
begin
for i := 0 to Count - 1 do
Items[i].Free;
inherited;
end;
function TMyRecList.Get(Index: Integer): TMyRec;
begin
Result := TMyRec(inherited Get(Index));
end;
var
MyRecList: TMyRecList;
MyRec: TMyRec;
tmp: Integer;
begin
MyRecList := TMyRecList.Create;
for tmp := 0 to 9 do
begin
MyRec:= TMyRec.Create;
MyRec.Value := tmp;
MyRec.AByte := Byte(tmp);
MyRecList.Add(MyRec);
end;
for tmp := 0 to MyRecList.Count - 1 do
Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ',
MyRecList[tmp].AByte);
WriteLn(' Press Enter to free the list');
ReadLn;
MyRecList.Free;
end.
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Re: [fpc-pascal] Help with TList example
See https://www.freepascal.org/docs-html/rtl/system/dispose.html
On 08/09/2020 12:51, James Richters wrote:
Can you please give me an example of the correct way to use new and dispose?
I'll try the pointer
Thanks for the advice
James
-Original Message-
From: fpc-pascal On Behalf Of Tony
Whyman via fpc-pascal
Sent: Tuesday, September 8, 2020 7:21 AM
To: fpc-pascal@lists.freepascal.org
Cc: Tony Whyman
Subject: Re: [fpc-pascal] Help with TList example
Two observations:
1. In Pascal you should use "new" and "dispose" to allocate and deallocate
record types - not GetMem and FreeMem.
2. MyRec is a pointer type and you should code the line as
MyRec^.Value := tmp
On 08/09/2020 12:10, James Richters via fpc-pascal wrote:
I'm trying to figure out how TList works. I found the code example below by
doing a search, but I can't compile it, I get Error: Illegal qualifier on the
line
MyRec.Value := tmp;
It's indicating the error is on the V of Value
I tried commenting that line out, then I get the same error on
MyRec.AByte := Byte(tmp);
At the A of AByte
So I commented that out too and then I get the error on
Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ',
MyRecList[tmp].AByte); At the V on Value after MyRecList[tmp].
I don't know enough about the syntax to figure out what's wrong here. Does
anyone have any ideas? It seems like there is something fundamentally wrong.
I'm trying to make a temporary list of records. Kind of like a TStringList,
but instead of a list of strings, a list of my own custom records. Perhaps
there is a better way?
program Project1;
{$mode objfpc}{$H+}
uses
SysUtils, Classes;
type
PMyRec=^TMyRec;
TMyRec=record
Value: Integer;
AByte: Byte;
end;
TMyRecList=class(TList)
private
function Get(Index: Integer): PMyRec;
public
destructor Destroy; override;
function Add(Value: PMyRec): Integer;
property Items[Index: Integer]: PMyRec read Get; default;
end;
{ TMyRecList }
function TMyRecList.Add(Value: PMyRec): Integer; begin
Result := inherited Add(Value);
end;
destructor TMyRecList.Destroy;
var
i: Integer;
begin
for i := 0 to Count - 1 do
FreeMem(Items[i]);
inherited;
end;
function TMyRecList.Get(Index: Integer): PMyRec; begin
Result := PMyRec(inherited Get(Index)); end;
var
MyRecList: TMyRecList;
MyRec: pMyRec;
tmp: Integer;
begin
MyRecList := TMyRecList.Create;
for tmp := 0 to 9 do
begin
GetMem(MyRec, SizeOf(TMyRec));
MyRec.Value := tmp;
MyRec.AByte := Byte(tmp);
MyRecList.Add(MyRec);
end;
for tmp := 0 to MyRecList.Count - 1 do
Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ',
MyRecList[tmp].AByte);
WriteLn(' Press Enter to free the list');
ReadLn;
MyRecList.Free;
end.
James
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Re: [fpc-pascal] Help with TList example
Can you please give me an example of the correct way to use new and dispose?
I'll try the pointer
Thanks for the advice
James
-Original Message-
From: fpc-pascal On Behalf Of Tony
Whyman via fpc-pascal
Sent: Tuesday, September 8, 2020 7:21 AM
To: fpc-pascal@lists.freepascal.org
Cc: Tony Whyman
Subject: Re: [fpc-pascal] Help with TList example
Two observations:
1. In Pascal you should use "new" and "dispose" to allocate and deallocate
record types - not GetMem and FreeMem.
2. MyRec is a pointer type and you should code the line as
MyRec^.Value := tmp
On 08/09/2020 12:10, James Richters via fpc-pascal wrote:
> I'm trying to figure out how TList works. I found the code example below by
> doing a search, but I can't compile it, I get Error: Illegal qualifier on
> the line
> MyRec.Value := tmp;
>It's indicating the error is on the V of Value
>
> I tried commenting that line out, then I get the same error on
> MyRec.AByte := Byte(tmp);
> At the A of AByte
>
> So I commented that out too and then I get the error on
>
> Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ',
> MyRecList[tmp].AByte); At the V on Value after MyRecList[tmp].
>
> I don't know enough about the syntax to figure out what's wrong here. Does
> anyone have any ideas? It seems like there is something fundamentally wrong.
>
> I'm trying to make a temporary list of records. Kind of like a TStringList,
> but instead of a list of strings, a list of my own custom records. Perhaps
> there is a better way?
>
>
> program Project1;
> {$mode objfpc}{$H+}
>
> uses
>SysUtils, Classes;
>
> type
>PMyRec=^TMyRec;
>TMyRec=record
> Value: Integer;
> AByte: Byte;
>end;
>
>TMyRecList=class(TList)
>private
> function Get(Index: Integer): PMyRec;
>public
> destructor Destroy; override;
> function Add(Value: PMyRec): Integer;
> property Items[Index: Integer]: PMyRec read Get; default;
>end;
>
> { TMyRecList }
>
> function TMyRecList.Add(Value: PMyRec): Integer; begin
>Result := inherited Add(Value);
> end;
>
> destructor TMyRecList.Destroy;
> var
>i: Integer;
> begin
>for i := 0 to Count - 1 do
> FreeMem(Items[i]);
>inherited;
> end;
>
> function TMyRecList.Get(Index: Integer): PMyRec; begin
>Result := PMyRec(inherited Get(Index)); end;
>
> var
>MyRecList: TMyRecList;
>MyRec: pMyRec;
>tmp: Integer;
> begin
>MyRecList := TMyRecList.Create;
>for tmp := 0 to 9 do
>begin
> GetMem(MyRec, SizeOf(TMyRec));
> MyRec.Value := tmp;
> MyRec.AByte := Byte(tmp);
> MyRecList.Add(MyRec);
>end;
>
>for tmp := 0 to MyRecList.Count - 1 do
> Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ',
> MyRecList[tmp].AByte);
>WriteLn(' Press Enter to free the list');
>ReadLn;
>MyRecList.Free;
> end.
>
> James
>
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Re: [fpc-pascal] Ethernet Relays
On Tue, 8 Sep 2020, James Richters via fpc-pascal wrote:
I added ssockets now I can compile it.
I have this working with the ssockets unit added:
Try
S:=TFPHTTPCLIENT.SIMPLEGET('http://10.10.01.01/3/15');
except
On E: ESocketError do
Writeln('Could not connect to server'); end;
But when I try the version with the timeout, I always get the error.
What is the proper way to get the page into a variable with the timeout method?
I tried S:= C.Get('http://10.10.01.01/3/15'); But I'm not sure that's the
right way to do it, but even without the S:= I always get the EsocketError
What timeout did you use ? 10 ms is probably too short.
Michael.
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Re: [fpc-pascal] Help with TList example
Two observations:
1. In Pascal you should use "new" and "dispose" to allocate and
deallocate record types - not GetMem and FreeMem.
2. MyRec is a pointer type and you should code the line as
MyRec^.Value := tmp
On 08/09/2020 12:10, James Richters via fpc-pascal wrote:
I'm trying to figure out how TList works. I found the code example below by
doing a search, but I can't compile it, I get Error: Illegal qualifier on the
line
MyRec.Value := tmp;
It's indicating the error is on the V of Value
I tried commenting that line out, then I get the same error on
MyRec.AByte := Byte(tmp);
At the A of AByte
So I commented that out too and then I get the error on
Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ', MyRecList[tmp].AByte);
At the V on Value after MyRecList[tmp].
I don't know enough about the syntax to figure out what's wrong here. Does
anyone have any ideas? It seems like there is something fundamentally wrong.
I'm trying to make a temporary list of records. Kind of like a TStringList,
but instead of a list of strings, a list of my own custom records. Perhaps
there is a better way?
program Project1;
{$mode objfpc}{$H+}
uses
SysUtils, Classes;
type
PMyRec=^TMyRec;
TMyRec=record
Value: Integer;
AByte: Byte;
end;
TMyRecList=class(TList)
private
function Get(Index: Integer): PMyRec;
public
destructor Destroy; override;
function Add(Value: PMyRec): Integer;
property Items[Index: Integer]: PMyRec read Get; default;
end;
{ TMyRecList }
function TMyRecList.Add(Value: PMyRec): Integer;
begin
Result := inherited Add(Value);
end;
destructor TMyRecList.Destroy;
var
i: Integer;
begin
for i := 0 to Count - 1 do
FreeMem(Items[i]);
inherited;
end;
function TMyRecList.Get(Index: Integer): PMyRec;
begin
Result := PMyRec(inherited Get(Index));
end;
var
MyRecList: TMyRecList;
MyRec: pMyRec;
tmp: Integer;
begin
MyRecList := TMyRecList.Create;
for tmp := 0 to 9 do
begin
GetMem(MyRec, SizeOf(TMyRec));
MyRec.Value := tmp;
MyRec.AByte := Byte(tmp);
MyRecList.Add(MyRec);
end;
for tmp := 0 to MyRecList.Count - 1 do
Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ', MyRecList[tmp].AByte);
WriteLn(' Press Enter to free the list');
ReadLn;
MyRecList.Free;
end.
James
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[fpc-pascal] Help with TList example
I'm trying to figure out how TList works. I found the code example below by
doing a search, but I can't compile it, I get Error: Illegal qualifier on the
line
MyRec.Value := tmp;
It's indicating the error is on the V of Value
I tried commenting that line out, then I get the same error on
MyRec.AByte := Byte(tmp);
At the A of AByte
So I commented that out too and then I get the error on
Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ', MyRecList[tmp].AByte);
At the V on Value after MyRecList[tmp].
I don't know enough about the syntax to figure out what's wrong here. Does
anyone have any ideas? It seems like there is something fundamentally wrong.
I'm trying to make a temporary list of records. Kind of like a TStringList,
but instead of a list of strings, a list of my own custom records. Perhaps
there is a better way?
program Project1;
{$mode objfpc}{$H+}
uses
SysUtils, Classes;
type
PMyRec=^TMyRec;
TMyRec=record
Value: Integer;
AByte: Byte;
end;
TMyRecList=class(TList)
private
function Get(Index: Integer): PMyRec;
public
destructor Destroy; override;
function Add(Value: PMyRec): Integer;
property Items[Index: Integer]: PMyRec read Get; default;
end;
{ TMyRecList }
function TMyRecList.Add(Value: PMyRec): Integer;
begin
Result := inherited Add(Value);
end;
destructor TMyRecList.Destroy;
var
i: Integer;
begin
for i := 0 to Count - 1 do
FreeMem(Items[i]);
inherited;
end;
function TMyRecList.Get(Index: Integer): PMyRec;
begin
Result := PMyRec(inherited Get(Index));
end;
var
MyRecList: TMyRecList;
MyRec: pMyRec;
tmp: Integer;
begin
MyRecList := TMyRecList.Create;
for tmp := 0 to 9 do
begin
GetMem(MyRec, SizeOf(TMyRec));
MyRec.Value := tmp;
MyRec.AByte := Byte(tmp);
MyRecList.Add(MyRec);
end;
for tmp := 0 to MyRecList.Count - 1 do
Writeln('Value: ', MyRecList[tmp].Value, ' AByte: ', MyRecList[tmp].AByte);
WriteLn(' Press Enter to free the list');
ReadLn;
MyRecList.Free;
end.
James
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Re: [fpc-pascal] Ethernet Relays
I added ssockets now I can compile it.
I have this working with the ssockets unit added:
Try
S:=TFPHTTPCLIENT.SIMPLEGET('http://10.10.01.01/3/15');
except
On E: ESocketError do
Writeln('Could not connect to server'); end;
But when I try the version with the timeout, I always get the error.
What is the proper way to get the page into a variable with the timeout method?
I tried S:= C.Get('http://10.10.01.01/3/15'); But I'm not sure that's the
right way to do it, but even without the S:= I always get the EsocketError
uses fphttpclient,ssockets;
Var
C : TFPHTTPClient;
begin
C:=TFPHTTPClient.Create(Nil);
try
try
C.ConnectTimeout:=10; // Or whatever you think is good
C.Get('http://10.10.01.01/3/15');
except
On E: ESocketError do
Writeln('Could not connect to server');
end;
finally
C.Free;
end;
end;
James
-Original Message-
From: fpc-pascal On Behalf Of Michael
Van Canneyt via fpc-pascal
Sent: Tuesday, September 8, 2020 2:51 AM
To: James Richters ; FPC-Pascal users
discussions
Cc: Michael Van Canneyt
Subject: Re: [fpc-pascal] Ethernet Relays
Add the ssockets unit to your uses clause.
Michael
On Mon, 7 Sep 2020, James Richters via fpc-pascal wrote:
> When I try to compile either of the examples below, I get Error: Identifier
> not found "ESocketError"
> Any ideas?
>
> James
>
>
> Yes, catch the ESocketError in a try..except:
>
> Try
> S:=TFPHTTPCLIENT.SIMPLEGET('http://10.10.01.01/3/15');
> except
> On E: ESocketError do
> Writeln('Could not connect to server'); end;
>
>> Is there a way to change the amount of time before the timeout?
>
> Yes, but then you need to create an instance, i.e. the Simple* commands won't
> do that for you:
>
> Instead, it will look like this:
>
> uses fphttpclient;
>
> Var
> C : TFPHTTPClient;
>
> begin
> C:=TFPHTTPClient.Create(Nil);
> try
> try
>C.ConnectTimeout:=10; // Or whatever you think is good
>C.Get('http://10.10.01.01/3/15');
> except
>On E: ESocketError do
> Writeln('Could not connect to server');
> end;
> finally
> C.Free;
> end;
> end;
>
> Michael.
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Re: [fpc-pascal] Ethernet Relays
Add the ssockets unit to your uses clause.
Michael
On Mon, 7 Sep 2020, James Richters via fpc-pascal wrote:
When I try to compile either of the examples below, I get Error: Identifier not found "ESocketError"
Any ideas?
James
Yes, catch the ESocketError in a try..except:
Try
S:=TFPHTTPCLIENT.SIMPLEGET('http://10.10.01.01/3/15');
except
On E: ESocketError do
Writeln('Could not connect to server'); end;
Is there a way to change the amount of time before the timeout?
Yes, but then you need to create an instance, i.e. the Simple* commands won't
do that for you:
Instead, it will look like this:
uses fphttpclient;
Var
C : TFPHTTPClient;
begin
C:=TFPHTTPClient.Create(Nil);
try
try
C.ConnectTimeout:=10; // Or whatever you think is good
C.Get('http://10.10.01.01/3/15');
except
On E: ESocketError do
Writeln('Could not connect to server');
end;
finally
C.Free;
end;
end;
Michael.
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Re: [fpc-pascal] Why can I not build fpc 3.0.4 with ppcarm 3.0.0 or 3.0.4?
On Tue, 08 Sep 2020 00:59:51 +0200, Bo Berglund via fpc-pascal wrote: >Today when I was setting up a Raspberry PiZero I was hit with this >message when I was going to build fpc 3.0.4 (sources checked out from >svn): > >Makefile:2790: *** The only supported starting compiler version is >3.0.2. You are trying to build with .. Stop. > It turns out that this was a grossly misleading error message! The real problem was that the RPiZero is arm v6 and the seed compiler downloaded was arm v7! After changing to ppcarm 3.0.0 for arm6 the build works. -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
