I am using FlowCode to program an ESP32-Wroom, simply put a 3x4 keypad and a display. The keypad is connected like this:- byte pin_rows[ROW_NUM] = {19, 18, 5, 17}; // GPIO19, GPIO18, GPIO5, GPIO17 connect to the row pins byte pin_column[COLUMN_NUM] = {16, 4, 0}; An arduino sketch proves the hardware...