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: tinyos-help@millennium.berkeley.edu
> 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
> Tinyos-help@millennium.berkeley.edu
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>
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