Sorry about the link to my site, the machine is up but doesn't seem to be accessible from the outside world. Since it's free I'm getting what I pay for...mannana possible.
I think it's mostly the protocol, MAC backoffs, and the fact that you have to listen sometimes as well as send. You can of course hack into the CC1000 code and make it transmit-only or whatever. The MicaZ's will handle up to 200 msg/sec in the ideal world, but the poor '2's are not so sprightly. When you say app reqmt of 100Hz, do you mean you are trying to record a 100Hz signal? If that is the max, you have a 200 sample nyquist freq which you could aggregate into less than ten 29-byte messages. I'm sure there are other complications for your app, but them's the numbers. MS Edgar Charry wrote: > Hi all, > > Thanks for your prompt replies. Unfortunately I that link didn't let me > through. > > In fact I am still trying to undestand them, as I wasn't aware of that > limitation of 33-50ms of the Mica2's! You are saying that the maximum > bandwidth my app should require is 0-25Hz so that I have a nice > reconstruction of my wave, due to HW limitations? > I knew that the CC1000 has a maximum bandwidth of 76.8kbps and of course > due to EEPROM readings/writings, CPU instructions, ADC's > measurements etc. this number should decrease. But I wasn't expecting a > final bandwidth of 30pckts/s!!! In fact, I thought there were problems > related to the TOSBase. > My app requirement need at least 100Hz (Mica2's transmission needed thus > 200 pckts/s), which is necessary to track a complete gait cycle using > acc and gyros with good definition. > > What is the most critical factor in the Mica2's that blow the > transmission rate so bad? Does this happen with the Mica2Dot too? Data > compression (sample with a higher freq, store in the RAM and then send > the whole bunch of bytes) has a limitation of 29 bytes due to TinyOS, > correct? > > Thanks guys for the good info. > Cheers, > Edgar Charry > > > Date: Mon, 14 Apr 2008 12:20:38 -0600 > > From: [EMAIL PROTECTED] > > To: [EMAIL PROTECTED] > > CC: tinyos-help@millennium.berkeley.edu > > Subject: Re: [Tinyos-help] Pumping up bandwidth - Mica2Dot/Mica2 > > > > Well, since people are quoting my second source messages, have a look at: > > http://www.etantdonnes.com/Motes/report_mica2/ > > (which seems to be down right now but will hopefully be back soon...). > > > > However my message speed/reliability measurements use only the standard > > GenericComm and TOS1 code. I think the OP was trying to fiddle timeouts > > and backoffs to speed things up further. Data mining of the help list > > should turn up some more useful advice in this respect. > > > > MS > > > > Eric Keller wrote: > > > There is a limit to how many packets you can send with a mica2 > which you are > > > at or above. You probably want to lower your bandwidth requirements > somehow. > > > See this message: > > > > https://www.millennium.berkeley.edu/pipermail/tinyos-help/2008-April/032464.html > > > > > > Eric > > > > > > > > > On Mon, Apr 14, 2008 at 4:59 AM, Edgar Charry <[EMAIL PROTECTED]> > wrote: > > >> Hi all, > > >> > > >> I am trying to pump my packet transmission up between a Mica2Dot and a > > >> Mica2 to at least 200Hz [pckts/s]. > > >> > > >> I've decreased the timer constant to a bottleneck of 33ms (30 > pckts/s) that > > >> pratically executes a round of ADC measurements and send the packet. > > >> Decreasing from this point doesn't give me more bandwidth. However, my > > >> packet is 14bytes long (the TinyOS header + just a couple of adc > > >> measurements + CRC). > > >> > > >> I suspect that this 33ms (parsed time stamps from XSniffer) are > limited to > > >> the TOSBase.nc on the Mica2. I suspect that the PLL of the Mica2 is > > >> listening through channels and is not locked to the transmitter's > one. Every > > >> loop thus should take 33ms. > > >> > > >> Actually, I haven't been through the CC1000 conf/mod components > though, but > > >> I reckon with your experience this can be solved easily. > > >> Cheers, > > >> Edgar Charry > > >> > > >> ________________________________ > > >> Explore the seven wonders of the world Learn more! > > >> _______________________________________________ > > >> Tinyos-help mailing list > > >> Tinyos-help@millennium.berkeley.edu > > >> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > >> > > > _______________________________________________ > > > Tinyos-help mailing list > > > Tinyos-help@millennium.berkeley.edu > > > > 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 > > Tinyos-help@millennium.berkeley.edu > > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > > ------------------------------------------------------------------------ > Explore the seven wonders of the world Learn more! > <http://search.msn.com/results.aspx?q=7+wonders+world&mkt=en-US&form=QBRE> -- Platform: WinXP/Cygwin TinyOS version: 1.x, Boomerang Programmer: MIB510 Device(s): Mica2, MicaZ, Tmote Sensor board: homebrew _______________________________________________ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
