Thanks in advance ---------- Forwarded message ---------- From: Rodrigo Carbajales <[email protected]> Date: Thu, May 9, 2013 at 2:33 PM Subject: Re: [Tinyos-help] Z1 High speed i2c accelerometer sampling To: [email protected] Cc: Martín René Vilugrón <[email protected]>
Hi Antonio, My name is Rodrigo and I work with Martin Rene Vilugron at CNEA, Argentina. Thanks for the solution proposed. Now we can reach a sample frequency of 1KHz! I want to make another question, is it possible to use a faster timer? I use TimerMilli but it is not possible to use Timer32khz or TimerMicro? Regards, Rodrigo On 17 April 2013 10:06, Martín René <[email protected]> wrote: > Aceleración > --- > Martín René Vilugrón > San Carlos de Bariloche > Patagonia Argentina > > > ---------- Forwarded message ---------- > From: Antonio Linan <[email protected]> > Date: Wed, Apr 17, 2013 at 5:53 AM > Subject: Re: [Tinyos-help] Z1 High speed i2c accelerometer sampling > To: Martín René <[email protected]> > Cc: TinyOS Mailing Lists <[email protected]> > > > Hello again, > > Using the TestADXL345 example in /apps/tests/z1/Accelerometer I got some > numbers for you, basically you can: > > - Comment out the delay at /tos/chips/adxl345/adxl345P file in line 787. > - Edit the example and start the Accelerometer only once (in boot only), > then periodically sample 1 axis > > As it is the ubr (in /tos/platforms/z1/chips/msp430/usci/Z1UsciP.nc is set > to 800, as SMCLK is sourced from the DCO with /1 divider, this gives a > rough 10KHz clock (I measured this to be actually 9.8724Khz), giving you a > total reading time of 4.84ms (measured just before calling .read() and in > readDone() event). Changing the ubr to 80 you can get a 87.912Khz clock > (measured), with a reading time of 0.711ms. > > Hope this helps. > > Regards, > > --Antonio > > > On Tue, Apr 16, 2013 at 10:29 PM, Antonio Linan <[email protected]>wrote: > >> Hola! >> >> Yes, there might be room for improvement, if you look at the code it has >> an active waits (around line 787) that slow the readings but were >> necessary at the time, also one could try and configure the I2C module with >> different settings (UBR for example) to see if more speed is allowed. I >> have planned a revision of the usci driver, so things may change, in the >> meantime if you wanna dig a little you are welcome, che :) >> >> Saludos! >> >> --Antonio >> >> >> >> >> >> >> On Tue, Apr 16, 2013 at 7:16 PM, Martín René <[email protected]>wrote: >> >>> Sorry that i didn't make the interface problem clear... >>> >>> The accelerometer is digital using i2c interface, and doesn't provide a >>> readstream interface. >>> >>> With another sensor, we reached high sampling speeds using the >>> processor's ADC, but the bus does'nt seem to reach the necessary speeds, >>> maybe delays or something else slows down the sampling... >>> >>> >>> Saludos y muchas gracias! >>> >>> --- >>> Martín René Vilugrón >>> San Carlos de Bariloche >>> Patagonia Argentina >>> >>> >>> On Tue, Apr 16, 2013 at 1:58 PM, Michael Schippling >>> <[email protected]>wrote: >>> >>>> There are some intriguingly named files containing "Stream" and "DMA" >>>> in the ...tinyos-2.x_main/tos/chips/**msp430/adc12 directory. Some of >>>> them even have comments which reference TEP documents that might >>>> explain what they are trying to do. Maybe one of them will allow >>>> you to run the ADC at higher rates... >>>> >>>> In T1 with the mica's (what I know....) one could free-run a single >>>> ADC at low audio rates by bypassing most of TOS. >>>> >>>> MS >>>> >>>> >>>> >>>> On 4/15/2013 1:27 PM, Martín René wrote: >>>> >>>>> We are currently using the Z1 Motes and sampling at 200Hz without >>>>> problems, but we can't raise the sampling speed above said speed >>>>> without >>>>> starting to have problems. We need to sample at 1000Hz and we can't get >>>>> there. >>>>> >>>>> I know that the resources of the platform are scarse, but i know that >>>>> the ADC can manage those speeds, and as we don't have a analog >>>>> accelerometer we neee to speed up all we can the ADXL. >>>>> >>>>> Is it possible to sample the accelometer at those speeds? >>>>> If it is, ¿how? >>>>> >>>>> Thanks! and saludos >>>>> >>>>> --- >>>>> Martín René Vilugrón >>>>> San Carlos de Bariloche >>>>> Patagonia Argentina >>>>> >>>>> >>>>> ______________________________**_________________ >>>>> Tinyos-help mailing list >>>>> Tinyos-help@millennium.**berkeley.edu<[email protected]> >>>>> https://www.millennium.**berkeley.edu/cgi-bin/mailman/** >>>>> listinfo/tinyos-help<https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help> >>>>> >>>>> >>> >>> _______________________________________________ >>> Tinyos-help mailing list >>> [email protected] >>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>> >> >> >> >> -- >> -- >> Antonio Liñan Colina >> R+D+I Engineer >> @: [email protected] >> @: [email protected] >> ------------------------------ >> Advancare >> T: +34 93 582 02 70 >> http://www.advancare.com >> http://www.zolertia.com >> http://zolertia.sourceforge.net >> http://webshop.zolertia.com >> > > > > -- > -- > Antonio Liñan Colina > R+D+I Engineer > @: [email protected] > @: [email protected] > ------------------------------ > Advancare > T: +34 93 582 02 70 > http://www.advancare.com > http://www.zolertia.com > http://zolertia.sourceforge.net > http://webshop.zolertia.com > >
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