I could use some advice with this part. The photograph below shows what I'm planning on mounting behind the TV facia. The board with the red LEDs is an old Wizard game that should be fairly easy to install (it just needs 1 power line, 1 speaker and 4 buttons connecting), but the white LEDs I'm having problems with. They're supposed to show numbers by taking each bar as a single digit, so the right hand bar is units, the middle is tens, the left is hundreds. The input to the system is going to be a rotary phone dial, so numbers can be dialed in and added to the total. It's supposed to be a graphical representation of basic maths.
The way I was going to do this was to have 3 4017 decade counters. Each runs it's own bar of LEDs, with the 0 output unused. The units is clocked by the dial, the tens is clocked by the units, the hundreds clocked by the tens, so that as each bar rolls over it adds 1 to the next bar. I'll also be adding a reset button.
Here's the problem, The chip I've been testing always starts at 1 but resets to 0, so how do I do this without having it start at 111?
I take it I can't use the /10 output to generate a clock signal or the numbers will be in the wrong order (1,2,3,4,15,16,17,18,19,10,11...), but if I use the 0 output, won't that add 1 to the next line when the reset button is pressed?
Any advice would be much appreciated.
- WIP of the innards of a display.