Adafruit‐Grand‐Central‐Alpha board Pin Out - johnttaylor/epc GitHub Wiki

IOH Header (Digital Pins 13-8)

Header Pin	MCU Pin	Arduino/BSP Symbol	Type	Function
SCL	PB21	PIN_WIRE_SCL	out	SCLK I2C
SDA	PB20	PIN_WIRE_SDA	bi-directional	DATA I2C
AREF	PA03	---	Analog Reference	Not-Used (the internal VDDANA 3.3V is used instead).
GND	---	---	GND	Ground
12	PB00	PIN_BUTTON_A	in	Input Button A (asserted:=0V)
11	PB23	PIN_BUTTON_B	in	Input Button B (asserted:=0V)
10	PB22	PIN_BUTTON_X	in	Input Button X (asserted:=0V)
9	PB02	PIN_BUTTON_Y	in	Input Button Y (asserted:=0V)
8	PB18	PIN_HW_SAFETY	in	HW Safety Limit Tripped (asserted:=0V)

IOL Header (Digital Pins 7-0)

Header Pin	MCU Pin	Arduino/BSP Symbol	Type	Function
7	PD21	PIN_RESET_LCD	out	Reset LCD Controller
6	PD20	PIN_DC_LCD	out	DC for the LCD Controller
5	PC21	PIN_PWM_LED_RED	out	PWM RGB-LED: RED
4	PC20	PIN_PWM_LED_GREEN	out	PWM RGB-LED: GREEN
3	PC19	PIN_PWM_LED_BLUE	out	PWM RGB-LED: BLUE
2	PC18	PIN_PWM_LCD_BACKLIGHT	out	PWM LCD Backlight

UART Header (Digital Pins 14-21)

Header Pin	MCU Pin	Arduino/BSP Symbol	Type	Function
18	PB12	PIN_PWM_HEATER	out	Heater PWM
19	PB13	PIN_PWM_FAN	out	Fan PWM

ANALOGL Header (Analog Pins 0-7)

Header Pin	MCU Pin	Arduino/BSP Symbol	Type	Function
0	PA02	PIN_ONBOARD_IDT	ain	Thermistor