Arduino: read a 4x4 membrane keypad with 8 pins
Read a 4x4 keypad with 8 Arduino pins instead of 16 by scanning rows and columns. The matrix-scan trick behind every keyboard ever made.
Tag
#input
2 tutorials
ESP32: GPIO basics, digital read, digital write, and the pull-up trick
How to read and write the ESP32's GPIO pins, when to use the internal pull-ups, and the input-only pins that catch everyone once.