Doubt-Ultrasonic sensor

Thanks you so much! I'm really pleased :slight_smile:

If that sensors are not valid, I'll try to look for another way to complete the project:

I was thinking about a IR led and and IR receiver (like that: http://es.farnell.com/vishay/tsop4838/ir-receiver-38khz/dp/4913190)

Could it work?

Can I build the theremin such as this one with my IR led and IR receiver?: http://mechomaniac.com/SimpleArduinoTheremin

Thanks you again :wink: