hi,
these circuit can be said that almost completed, but i found another problem. when there is no signal, yes, the output is high, but there is a low in very short time (i used cro to measure), as shown in A.
when there is signal, yes, i got square wave from the cro as shown in B.
my problem is, my microcontroller will keep reading to the output of the receiver. if there is a low (0), it will response to it and turn. but if there is a low when there is no signal, and if the microcontroller "assume" that it detects the signal because of the short low, then it will turn without any signal.
do u all get what i mean?