Hi!

Thanks Janos for your advices!

I've changed the serial speed to 230400 (because of serial speed declarations 
in GNU/Linux). It works :)
After simple test with printf() there is about 1 Kbyte/s :(
Than I've changed printf() test application. I supply printf() a string with 
about 250 characters, then flush(). I could read about 8.5 Kbyte/s. It's really 
more than standard for IRIS 57600 Kbit/s, but it is still less than standard 
for other platforms. I've used PrintfClient to get the data.

What do you think, is there a bottleneck easy to reprogram? I haven't tested 
yet how much traffic I can transmit throw ZigBee. If this will not more than 
8.5 Kbyte/s then there is no sense to work around serial communication.

Best regards,
Andrey


> Andrey:
> 
> I think the code change you're proposing should work.
> 
> >So atm128 doesn't have speed enough to guarantee 256 KBit/s
> >data connection pc<->mote? If one want this, one should
> >implement a different platform with another microcontroller?
> 
> There's a good chance that it works. Just give it a try. BTW, I bet you'll 
> never
>  be getting 250kbps worth of zigbee payload in through the radio...
> 
> >By the way, MIB520 has also a microcontroller on board.
> >Is USART of Mote directly connected to FTDI chip or
> >throw this microcontroller?
> 
> It's hooked up directly to the FTDI chip.
> 
> >It seems to be not so easy even at the standard serial speed :(
> Obviously, 57600bps might not be sufficient to push through all the incoming
>  radio traffic...
> 
> Janos
> 
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
>  On Behalf Of Andrey Gursky
> Sent: Thursday, June 12, 2008 6:00 AM
> To: [email protected]
> Subject: Re: [Tinyos-help] Mote-PC serial speed increasing
> 
> Thanks Janos!
> 
> > On the iris, the ubrr0 register is set, at initialization time, to a 
> > calibrated
> >  value for 57600bps. You can change the baud rate by writing this register.
> > 
> 
> I've found in $TOSROOT/tos/chips/atm128 this code:
> 
>   command error_t Init.init() {
>     if (PLATFORM_BAUDRATE == 19200UL)
>       m_byte_time = 200; // 1 TMicor ~= 2.12 us, one byte = 417us ~= 200
>     else if (PLATFORM_BAUDRATE == 57600UL)
>       m_byte_time = 68;  // 1 TMicor ~= 2.12 us, one byte = 138us ~= 65
>     return SUCCESS;
>   }
> 
> I could add the line like this (or I should seek on to find ubrr0?)
> ..
>     else if (PLATFORM_BAUDRATE == 256000UL)
>       m_byte_time = ----->15<-----;  // 1 TMicor ~= 2.12 us, one byte
>  = ----->31us<----- ~= ----->15<-----
> ..
> 
> > 
> > This should work with a MIB520, but it is problematic with a MIB510. Should
> >  you have the former programming board, the bottleneck will probably be the
> >  interrupt load on the mote in the pc->mote direction. Note that the serial
> >  stack doesn't buffer outgoing packets (mote->pc), so the app must assume
> >  a lossy mote->pc link.
> > 
> 
> I have MIB520 (with usb) :)
> So atm128 doesn't have speed enough to guarantee 256 KBit/s data connection
>  pc<->mote? If one want this, one should implement a different platform
>  with another microcontroller?
> 
> By the way, MIB520 has also a microcontroller on board. Is USART of Mote 
> directly
>  connected to FTDI chip or throw this microcontroller?
> 
> There is one post seems to achieve similar goal: the highest speed :) 
> https://www.millennium.berkeley.edu/pipermail/tinyos-help/2008-June/034218.html
> 
> It seems to be not so easy even at the standard serial speed :(
> 
> Could someone point me to reference where I can read about what the atm128x
>  has yet free to use as quick and reliable communication with PC (SPI, I2C)?
>  Or the best idea were to use other small design to exchange messages between
>  PC and ZigBee motes?
> 
> 
> 
> > 
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> >  On Behalf Of Andrey Gursky
> > Sent: Tuesday, June 03, 2008 6:16 AM
> > To: [email protected]
> > Subject: [Tinyos-help] Mote-PC serial speed increasing
> > 
> > Hi tinyOS-community!
> > 
> > It seems possible (according datasheet) to use USART of ATmega128x in >57600
> >  speed mode. Thus ZigBee functions of 250 Kbit/s it would be nice to have 
> > this
> >  speed also between basestation and PC.
> > Does somebody know exactly, whether it would be as of some other reasons not
> >  possible? Or have I to alter configuration in .../chip/atm1281 to get this

> >  working?
> > 
> > 
> > Best regards,
> > Andrey
> > 
> > P.S. Particularly I'm interesting in iris-motes.
> > _______________________________________________
> > Tinyos-help mailing list
> > [email protected]
> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
> >
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