I am designing a 30 minutes countdown timer with a LDR in the circuit.
So far i can`t even achieve a simple countup timer from 0-9 , please help.
Clock pulse (Astable multivibrator)- 555 timer circuit
4 bit counter wired as MOD 10 74LS293N
LED common anode.
It seems that your 555 timer isn't counting, I hooked up an oscilloscope to it to see what it was generating