I´m trying to design a sensor circuit for this ultrasonic sensor:
This is my current design:
I use an Arduino Mega 2560 with USB as power supply and serial connection.
I build a transmitter circuit with 24V supply for transmitter. I use the tone library to feed the gate of the mosfets with 40kHz.
My problem is that my sensor circuit only receives the signal within a 10cm distance. I want to get to 1m distance and since I try to use this circuit for trilateration I want the circuit to be as time invariant as possible.
I currently don´t have an oscilloscope. For example I have no idea what C2 does, but without it I receive random noise constantly.