Lets keep this on the help list in case anyone actually knows something... You might try putting LED toggles in the various code sections so you can measure the time taken. I didn't have the patience to make sense of the MSP manual vis instructions and MCLKs so if you say 500 instructions that really seems like it oughta be plenty. But of course, TOS has been optimized for indirection so there's probably more overhead than I expect....
MS Kirak, Hong wrote: > Hi, > > Actually, I'm talking about UART0 and I checked error flag of USART module > which indicates > some overrun errors. And I think interrupt handling codes of SFD pin and > FIFOP pin of CC2420 are > too long to handled within 69 micro seconds(552 cycle). I didn't measure the > cycles needed for interrupt handling, > but I can see huge atomic sections and lots of codes inside of interrupt > handler. > (cc2420/receive/CC2420ReceiveP.nc , cc2420/transmit/CC2420TransmitP.nc) > > Because such interrupts are occurred even if CC2420 doesn't grab the SPI > resource, I think > it can't be done by resource arbitration. > > Any advices will be highly appreciated. Thanks. > > Kirak > > -----Original Message----- > From: Michael Schippling [mailto:[EMAIL PROTECTED] > Sent: Friday, July 25, 2008 10:31 AM > To: Anton > Cc: Kirak, Hong; [email protected] > Subject: Re: [Tinyos-help] UART with RADIO stack > > Which UART? I think the USB side uses UART1 and that UART0 is > shared by the Radio and the expansion port. Thus U0 needs > some kind of arbitration if you want to use it yourself, > and that could lead to interference. > > Perhaps some interrupt handling problem crept into T2 such > that the two UARTs can't be used "simultaneously", but 70us > is a couple hundred instruction cycles which should be enough > to handle the traffic. > > I haven't done extensive testing with telosb and T1 but my > impression is that a basestation type Radio<->USB pass-through > can maintain a fair data rate. Would be interesting to compare > T1 and T2 in that respect I suppose... > > MS > > > > Anton wrote: >> Hi, >> >> I use uart and radio on TelosB and I have the same problem. A mote >> should receive a radio packet, extract some data and forward it to >> computer. When packets are sent by only one transmitter and arrive >> infrequently (say one packet per second) everything is all right, the >> mote receives packets, transfers them to computer and computer receives >> correct data. When additional transmitters send their packets (not >> intended for the uart-using mote, i.e. address recognition should fail >> in such a case) computer receives some garbage instead of correct data. >> Now I use TinyOS 2.x. As far as I remember there was no such problem in >> TinyOS 1.x applications. >> Probably, this is not very good solution, what I have applied: the >> mote collects packets and stores data in the memory, then (when there is >> no longer any radio communication) it can calmly send the data via uart >> after I press the user button. May be the right thing to do is to reduce >> uart baud rate. >> >> Anton. >> >> _______________________________________________ >> Tinyos-help mailing list >> [email protected] >> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help -- Platform: WinXP/Cygwin TinyOS version: 1.x, Boomerang Programmer: MIB510 Device(s): Mica2, MicaZ, Tmote Sensor board: homebrew _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
