Arduino library to stitch muliple 4x4 matrix keypads into an analog QWERTY keyboard for Arduino & STM32 microcontrollers.
Requires a voltage bridge circuit (see primitive schematic below) consisting of three 2.2k ohm resistors connected in series between the rows and three 10k resistors connected between the columns. Since the buttons are arranged in a grid of 4 rows and 4 columns (with a different row/column pin combination for each button), each key press should create its own unique voltage* which is sent to a microcontroller's analog pin (with a pull down resistor on the common ground to default LOW)**
(Build 3 of these to string 3 keypads together for 48 keys - MORE than enough for a modest QWERTY layout!!)
* technically a range of voltages which have only been tessted at room temperature so far ha ha ha
** I am a total electronoob if you couldn't tell. Feedback greatly appreciated!