Hello, everyone! I'm a first-time poster who's having a little trouble with a project that I'm working on.
To give some background, I'm studying electronics at a two-year technical school. I'm at the end of my first year, and we're currently discussing digital circuits and the like.
What I had to do was set up a counter with a 74192, 7447, and 7-segment display. I managed to get the basic function of the circuit to work. I can get it yo count up 0-9 and down 9-0. My instructor wants me to set it up so it'll count down from 5-9. So, the counting sequence will look like this: 5, 4, 3, 2, 1, 0, 9, 5, 4, 3, and so on...
What I did to work on it, I decided to tie in the binary output for five (LEDs A and C) into a NAND gate; this output than went into the Parallel Load (pin 11) of the 74192. The other thing that I did was to tie LED D (representing binary for 8) into one of the input pins. No matter what input pin (1, 9, 10, 15), I just get a static number. I also thought putting into the master reset would fix it, but that didn't work, either.
I worked on it for 3 or 4 hours Thursday with no solution. I was wondering if I could receive some guidance as to what I'm doing wrong, and sorry if I come of as lazy or demanding help. Thanks, everyone!
(I also attached two pictures so you'll have a reference. Excuse my handwriting.)
To give some background, I'm studying electronics at a two-year technical school. I'm at the end of my first year, and we're currently discussing digital circuits and the like.
What I had to do was set up a counter with a 74192, 7447, and 7-segment display. I managed to get the basic function of the circuit to work. I can get it yo count up 0-9 and down 9-0. My instructor wants me to set it up so it'll count down from 5-9. So, the counting sequence will look like this: 5, 4, 3, 2, 1, 0, 9, 5, 4, 3, and so on...
What I did to work on it, I decided to tie in the binary output for five (LEDs A and C) into a NAND gate; this output than went into the Parallel Load (pin 11) of the 74192. The other thing that I did was to tie LED D (representing binary for 8) into one of the input pins. No matter what input pin (1, 9, 10, 15), I just get a static number. I also thought putting into the master reset would fix it, but that didn't work, either.
I worked on it for 3 or 4 hours Thursday with no solution. I was wondering if I could receive some guidance as to what I'm doing wrong, and sorry if I come of as lazy or demanding help. Thanks, everyone!
(I also attached two pictures so you'll have a reference. Excuse my handwriting.)
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