Anyone know how much voltage runs through the key matrix when a button is pushed?
It's related to the amount of voltage the microcontroller wants to scan the matrix with, 5V is a common value, I think. The current is really low, milliAmps at the most. Cherry MX switches are rated for 10mA max.
@ jonathanyu,
THere are more than one firmware that can run on the phantom. I'm using the phantom firmware, and there is also hasu's tmk_firmware, which spamray recommended.
The easiest is if you don't want to change the keymap from the default. If that's the case, you can often just find a precompiled firmware to run on your keyboard. Make sure you can do that first so you can test the keyboard hardware. Then, when you know that's working, then you can play with the source and building different layouts and all.
So, if you want to go with the bpiphany phantom firmware (like what I'm using to type this post now) you can download a precompiled .dex file from his github, linked below
https://github.com/BathroomEpiphanies/AVR-Keyboard/tree/master/firmwaresphantom ansi iso or ansi iso win should work depending on what KB you made.
so just download the hex and the teensy loader from pjrc. Plug in the keyboard, run teensy loader, press the button, select your firmware, upload it, reboot it and you should be good to go. instructions for usinmg teensy loader are included on it's page, link below
http://www.pjrc.com/teensy/loader.htmlI didn't see any precompiled firmware for hasu's tmk_firmware, so if you can't find any, you'll need to build it from source, which I can't help you with at this time (I haven't yet done it myself!)
Hope this helps