GPIO Pin Reference

Button Inputs

GPIO	Button Location	I/O
GPIO32	Button 1 (Top)	Input
GPIO33	Button 2 (Middle)	Input
GPIO34	Button 3 (Bottom)	Input
GPIO0	Boot (Internal Only)	Input

Display Signals

GPIO	Display Signal Name	I/O
GPIO17	RS	Output
GPIO18	E	Output
GPIO23	DB4	Output
GPIO25	DB5	Output
GPIO26	DB6	Output
GPIO27	DB7	Output
GPIO13	LCD Backlight	Output

Fault LED

GPIO	Signal Name	I/O
GPIO14	Fault led	Output

I2C signals

GPIO	Signal Name	I/O
GPIO21	SDA	Inout
GPIO22	SCL	Output

Valve 0 Enable

GPIO	Signal Name	I/O
GPIO19	Valve 0 Enable	Output

Watchdog Relay

GPIO	Signal Name	I/O
GPIO16	Watchdog Relay	Output