Hello All, I am currently working on a countdown timer circuit that is two digits and counts down every second from 30 to 0 using two 7 segment displays. I am going to use a 555 timer to make it send pulses every second. Along with a BCD to display the numbers onto the displays. The hardest part is finding a circuit layout that will decrement down instead of increment along with being able to preset the value it starts at to 30.
It has to be completely digital so no PIC chips. I wanted to use jk flip flops but am not sure how to make them count down, but do know how to make them count up. Any help will be much appreciated as I am stumped on how to make this work.
It has to be completely digital so no PIC chips. I wanted to use jk flip flops but am not sure how to make them count down, but do know how to make them count up. Any help will be much appreciated as I am stumped on how to make this work.