Dear Niamh, thank you so much! I'm really sorry...it was my fault. I misinterpreted the instruction in the README file thinking that the configuration file is called while compiling the firmware. Before, indeed, I didn't save the sample.cfg file in the SD card. Now it works correctly. Last question....would be it possible to set different sampling frequencies for the sensors? (in particular for the accelerometer and ECG)
Have a nice evening, Gabriele On 3 October 2012 17:45, Niamh O'Mahony <[email protected]>wrote: > Hi again Gabriele,**** > > ** ** > > A correction to your MATLAB code that I forgot to mention – you must skip > 10 bytes when you read the accelx, accely and accelz values, not 4 bytes. > This, along with my previous email should solve your problem.**** > > ** ** > > Best regards,**** > > Niamh**** > > ** ** > ------------------------------ > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Niamh O'Mahony > *Sent:* 03 October 2012 16:33 > *To:* 'Gabriele Spina'; [email protected] > *Subject:* Re: [Shimmer-users] ParamLogging**** > > ** ** > > Hi Gabriele,**** > > ** ** > > Your code looks fine – I’ve tested the MATLAB version with data output by > ParamLogging and it’s giving me meaningful results. I suggest you check > that you have saved the sample.cfg file in the top level directory of the > SD card on the shimmer and make sure that you have both the accelerometer > and gyroscope selected. (The example sample.cfg file from the ParamLogging > directory selects accelerometer and magnetometer by default so this will > have to be changed accordingly.) If ParamLogging does not find the > sample.cfg file in the top level directory of the SD card it should briefly > flash the red LED in warning and, then, default to logging accelerometer > data only. **** > > ** ** > > Also, a word of caution - if the magnetometer is selected in sample.cfg > but a magnetometer daughtercard is not present, datalogging will fail and > the shimmer will need to be reset.**** > > ** ** > > I hope this helps.**** > > ** ** > > Best regards,**** > > Niamh**** > > ** ** > ------------------------------ > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Gabriele Spina > *Sent:* 03 October 2012 14:09 > *To:* [email protected] > *Subject:* [Shimmer-users] ParamLogging**** > > ** ** > > Dear all,**** > > ** ** > > I'm trying to use the ParamLogging application > (.../tiny2/tinyos-2.x-contrib/shimmer/apps/ParamLogging) to log > accelerometer and gyro values.**** > > Thanks to Mike I'm able to compile and run it, but when I try to read the > data from the SD card I get weird results.**** > > ** ** > > I tried both the Matlab code in the manual and the python code read_em.py > suggested to read data recorded using JustFATLogging.**** > > ** ** > > Hereby you can see the code that I used:**** > > ** ** > > MATLAB:**** > > fid = fopen('.../../acceltot.bin');**** > > ** ** > > more off**** > > ** ** > > accelx = fread(fid, 'uint16', 4);**** > > ** ** > > L = length(accelx);**** > > t = (0:L-1)/50;**** > > ** ** > > frewind(fid);**** > > fseek(fid,2,'bof');**** > > ** ** > > accely = fread(fid, 'uint16', 4);**** > > ** ** > > frewind(fid);**** > > fseek(fid,4,'bof');**** > > ** ** > > accelz = fread(fid, 'uint16', 4);**** > > ** ** > > frewind(fid);**** > > fseek(fid,6,'bof');**** > > ** ** > > gyrox = fread(fid, 'uint16', 10);**** > > ** ** > > frewind(fid);**** > > fseek(fid,8,'bof');**** > > ** ** > > gyroy = fread(fid, 'uint16', 10);**** > > ** ** > > frewind(fid);**** > > fseek(fid,10,'bof');**** > > ** ** > > gyroz = fread(fid, 'uint16', 10);**** > > ** ** > > figure**** > > subplot(3,1,1); plot(accelx, 'r'); title 'Accel X';**** > > ** ** > > subplot(3,1,2); plot(accely, 'g'); title 'Accel Y';**** > > subplot(3,1,3); plot(accelz, 'b'); title 'Accel Z';**** > > ** ** > > figure**** > > subplot(3,1,1); plot(gyrox, 'r'); title 'Gyro X';**** > > subplot(3,1,2); plot(gyroy, 'g'); title 'Gyro Y';**** > > subplot(3,1,3); plot(gyroz, 'b'); title 'Gyro Z';**** > > ** ** > > ** ** > > ** ** > > ** ** > > Python**** > > ** ** > > ** ** > > > > **** > > #!/usr/bin/python**** > > ** ** > > import os, sys**** > > import array**** > > ** ** > > USAGE_TEXT = """**** > > Usage: read_em.py <datafile>**** > > """**** > > ** ** > > def usage():**** > > print USAGE_TEXT**** > > sys.exit(-1)**** > > ** ** > > def read_it(filename):**** > > try:**** > > f = open(filename, 'r')**** > > except:**** > > print "can't open %s for read" % filename**** > > sys.exit(-2)**** > > **** > > finfo = os.stat(filename)**** > > sz = finfo.st_size**** > > ** ** > > ** ** > > ** ** > > sz = sz / 2**** > > data = array.array('H')**** > > data.fromfile(f, sz)**** > > ** ** > > f.close()**** > > ** ** > > return data**** > > ** ** > > def print_em(data):**** > > t = 0.00**** > > ** ** > > s = len(data)**** > > for i in range(0,s,6):**** > > try:**** > > print "%04.02f\t%d\t%d\t%d\t%d\t%d\t%d" % (t, data[i], > data[i+1], data[i+2],data[3], data[i+4], data[i+5])**** > > except:**** > > print "file has truncated data at index %d" % i**** > > return**** > > **** > > t = t + 0.02**** > > **** > > def main(argv): **** > > if len(argv) < 1:**** > > usage() **** > > ** ** > > data = read_it(argv[0])**** > > ** ** > > print_em(data)**** > > **** > > if __name__ == "__main__":**** > > main(sys.argv[1:])**** > > ** ** > > ** ** > > ** ** > > When I try to plot the data I get almost the same plots for accelerometer > values and gyro values and they look like the charger of a condenser....** > ** > > I'm wondering if I'm doing some mistake reading the data or the > ParamLogging application has some bugs....did anyone use it before?**** > > ** ** > > Thanks a lot for your help.**** > > Gabriele**** >
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