pinout Atmega328p (2x14 pins) as I2C keyboard slave --------------------------------------------------- V2 V1 V1 V2 RESET 01 28 I2C SCL 9 02 x 27 I2C SDA 8 03 x 26 3 ROW OUT 3 7 04 x 24 2 ROW OUT 2 4 ROW OUT 4 05 25 1 ROW OUT 1 6 COL IN 9 06 x 23 0 ROW OUT 0 V3.3v 07 22 GND GND 08 21 09 20 10 19 4 COL IN 5 COL IN 8 11 x 18 3 COL IN 4 COL IN 7 12 x 17 0 COL IN 3 COL IN 6 13 x x 16 1 COL IN 1 2 COL IN 5 14 x x 15 2 COL IN 0 ROW and COLUMNS numbers (for V1 and V2): 0 1 2 3 4 5 6 7 8 9 0 x x x x x x x x x x 1 x x x x x x x x x x 2 x x x x x x x x x x 3 x x x x x x x x x x 4 x x x x x x x x x x