now i try to design distance sensor for control speed motor.
i use ultrasonic sensor, PIC16F84A and comperator.
i use comperator for compare the voltage i set with voltage from the RX ultrasonic sensor...

but i cant mesure the voltage from ultasonic sensor..

what i know,
if distance small the voltage high
if distance long the voltage low.

i realy new in pic and ultrasonic sensor.

realy need help..

sorry for my bad engglis