Hi all,
I am developing a small vibration measurement system for my Master's degree project and I am a little bit stuck here.
I need to configure the Teensy3.2 to work as a microphone in order to be recognized by an Android mobile phone (Serial comunication is not an option due to the low speed), and perform in the Android device the FFT.
If I change the USB type to "Audio", the Serial port prints information fast enough to take that info and process it into Matlab to get the FFT representation and the RMS speed. I have tested it with a calibrator at 159HZ a driller at 50Hz and a fan at 33 Hz and works well in frequency domain and providing me the Speed RMS values, for a low cost system. This make me think that, for this small purposes, the ADXL345 + Teensy 3.2 is what I need for this project.
In order to send the accelerometer values trough USB as fast as I can, I started changing the USB type to "AUDIO" as I said previously, but I was not able to recognize that port neither in matlab or android (this makes me to take values after 1 second manually), so I started messing around with the Audio library WITHOUT the Audio shield.
At this point, I has been able to send the Z axis value to Audacity, as if Teensy was a microphone, but I don't think that I have achieved the best results because the frequency appears to be 172 Hz instead of 159Hz.
My question is: Is it possible, in any way an withoud adding the audio shield, configure the Audio library to read the ADXL345 accelerometer, which is an I2C device and not an analog one, and send axis values to the PC/ANDROID device?
Thanks!
I am developing a small vibration measurement system for my Master's degree project and I am a little bit stuck here.
I need to configure the Teensy3.2 to work as a microphone in order to be recognized by an Android mobile phone (Serial comunication is not an option due to the low speed), and perform in the Android device the FFT.
If I change the USB type to "Audio", the Serial port prints information fast enough to take that info and process it into Matlab to get the FFT representation and the RMS speed. I have tested it with a calibrator at 159HZ a driller at 50Hz and a fan at 33 Hz and works well in frequency domain and providing me the Speed RMS values, for a low cost system. This make me think that, for this small purposes, the ADXL345 + Teensy 3.2 is what I need for this project.
In order to send the accelerometer values trough USB as fast as I can, I started changing the USB type to "AUDIO" as I said previously, but I was not able to recognize that port neither in matlab or android (this makes me to take values after 1 second manually), so I started messing around with the Audio library WITHOUT the Audio shield.
At this point, I has been able to send the Z axis value to Audacity, as if Teensy was a microphone, but I don't think that I have achieved the best results because the frequency appears to be 172 Hz instead of 159Hz.
My question is: Is it possible, in any way an withoud adding the audio shield, configure the Audio library to read the ADXL345 accelerometer, which is an I2C device and not an analog one, and send axis values to the PC/ANDROID device?
Thanks!