Ultrasound recording

Is anyone aware of how to set up an ultrasound recording device using arduino? I had thought that perhaps I could use the ultrasound range plugin unit as a microphone but I couldn't get it to work.

Its my first time playing with this kind of stuff and I would really appreciate any help.



Do you want to actually record the ultra sound? If so what frequency exactly?

Basically you need to sample at twice the rate of the top frequency you want to record. With a Uno you can not read the A/D fast enough to get into the ultrasonic region. Maybe with a Due, Zero or Teensy you could get into the near ultrasonic.

I designed a recording bat detector once...

1/ you can't use the ultrasonic range transducers as mikes except over their very narrow tuned frequency range - I used a very small electret mike good for 200khz.

2/ A slowish microcontroller won't sample nearly quickly enough - I divided the input frequency by 16, and retained amplitude with a fast log detector....

the lot went onto a usb datastick as a .wav file. It had a 'vox' circuit - ie recording only hapenned when bat 'squeaks' happened - logged with a rtc derived timestamp .....

I actually used an MPS430 series device for this - it had to run for 2 weeks from 3 'c' cells.



ps it was used to determine whether bats were present for planning reasons!