Has your team ever needed to add more buttons to your control system than you had digital inputs? I know Team Fusion did last year...
Here's a video of the trick we used. It's been described before in the past, so I take no credit for it, plus is such a simple circuit, but the video describes how the circuit works, and the math behind it.
http://youtu.be/s06ELvpx2IY
To get this to work with your software, you can either take snapshots of the voltages using the Cypress board, or use the calculations, either should be correct. You'll want to provide an error range of ~+/- 5% for the typical gold banded resistors. Just a decent guess will probably suffice... such was +/- 50mV from your snapshot or calculated value.
CORRECTION: In the video, I say that the Cypress Power Supply voltage, or the VDD, is 5V. This is incorrect. It's actually 3.3V.
Sincerely,
Ryan Nazaretian
Team Fusion 364 Remote College Mentor
Also to note, this is my first How-To video, so comments and suggestions on how to make these is welcome. I'd love to know of good software to use. I have a MacBook Pro, and a Windows beastly desktop, so both OSX and Windows software suggestions will be great. It's not the best video, but hopefully it successfully conveys the content that I wanted to teach.
This video will hopefully be uploaded and ready by 8AM CST... it's a large file, and the internet service at my apartment complex where I stay is quite slow, so it will take a while.
To remain on topic, please PM the comments and suggestions, and keep the thread on questions for this circuit.
Good luck!