[Tinyos-help] About MTS310 board's microphone and Accelerometer

[Monica Bell]

Dear all,

I am using MTS310 board to collect data from all the sensors on the board. I am suing tinyos-1.1.11. I have following problems with the microphone and accel readings.

1) When I sample the microphone once every second, the output that I get is different from that when the microphone is sampled 10 times in a second. The difference is quite large. It is about 190 when I am sampling at once a second and about 485 when sampling at 10 times per second. To calibrate the readings from the sensors, I am using xlisten's formulae. Can someone guide me what is the problem and at what rate should we sample? I dont need to reprodce the sound- so I guess I dont need to sample at Nyquist rate.

2) Both the accelX and accelY readings are negative. Again, I am using the formula in xlisten application. Please let me know how fast should I sample the accelorometer and how should I interpret the values? I read in ADXL202E's datasheet that the unit is g and it should be 0 g when there is not acceleration. Also, even if if move the MTS310 board, both accelX and accelY remain unchanged (same negative values).

Thank you,
Monica



 
____________________________________________________________________________________
8:00? 8:25? 8:40? Find a flick in no time 
with the Yahoo! Search movie showtime shortcut.
http://tools.search.yahoo.com/shortcuts/#news
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.millennium.berkeley.edu/pipermail/tinyos-help/attachments/20070622/c338781e/attachment.htm