I have an audio switcher (Pyle PLV-SC44) with four inputs/four outputs in my home theater setup. This allows for simultaneous routing of any source to any device (quite a useful piece of equipment).
The device uses a simple 4-digit 7-segment LED to show which source (1-4) is routing to each destination. I'd like to use an Arduino with a 20x4 LCD module to create a much more user-friendly display showing which source is going to each destination. The built-in 4-digit LED is very unfriendly and also is in my stack of AV equipement.
I've spent (probably way too much) time thinking about the logic to determine the number being shown for each destination. I'm thinking that I can determine if it's a 1, 2, 3, or 4 by looking at segments C, G, and F for each of the 4 digits. If F is lit, then it must be a 4. If only C is lit, it must be a 1. if G is lit, but not C, then it must be a 2, etc. As said, I have the logic figured out and I'm confident I can figure out the coding for the logic.
Here's my challenge: How do I read the signal that's going to the 12-Pin 4-Digit LED on the Pyle device? I have determined that I only need to read 3 of the "segment" pins (to determine the digit), but all 4 of the common pins (to determine the position). I can easily disassemble to Pyle device to get to the header connectors used to connect the LED with ribbon cables. I'm just perplexed on how to connect this to the Arduino to read it. Also, what would the coding be to read?
To heighten the challenge, the LCD module I want to use for the "new" display will require 6 digital lines on my UNO, if I'm not mistaken, that will leave 8 available. Of course, all 6 of my analog lines are available, but I don't think that will help.
Thanks for any help to figure this out!