3.6 Extension Headers

The PIC32CM SG00/GC00 Curiosity Pro development board has two Extension headers, J400 and J401, which are Xplained Pro compatible interfaces that enable the use of existing expansion boards. Each interface consists of a dual-row, 20-pin, 100 mil pitch, right angle male header, while Xplained Pro extensions have their female counterparts. The Extension headers can be used to connect a variety of Xplained Pro extension boards or to access the pins of the target MCU directly, and some of these pins are shared between both Extension headers and even Arduino UNO R3 headers and mikroBUS socket.

Figure 3-9. EXT1 Extension Header (J400) Schematic

Table 3-3. Extension Header1 Pin Assignment
Pin Number	Pin Name	Description	GPIO
1	ID	Communication line to the ID chip on an extension board	-
2	GND	Ground	GND
3	ADC(+)	Analog-to-Digital converter, alternatively positive part of differential ADC	PA03
4	ADC(-)	Analog-to-Digital converter, alternatively negative part of differential ADC	PA04
5	GPIO1	General purpose I/O	PC00
6	GPIO2	General purpose I/O	PC01
7	PWM(+)	Pulse-Width Modulation, alternatively positive part of differential PWM	PA01
8	PWM(-)	Pulse-Width Modulation, alternatively negative part of differential PWM	PA02
9	IRQ/GPIO	Interrupt request line and/or general purpose I/O	PA00
10	SS/GPIO	Client select for SPI and/or general purpose I/O	PC09
11	TWD	Data line for I²C interface. Always implemented, bus type	PD01
12	TWCK	Clock line for I²C interface. Always implemented, bus type	PD00
13	RXD	Receiver line of target device UART	PB16
14	TXD	Transmitter line of target device UART	PB15
15	SS	Client select for SPI, should preferably be unique	PC10
16	MOSI	Host out Client in line of Serial Peripheral Interface	PA16
17	MISO	Host in Client out line of Serial Peripheral Interface	PA15
18	SCK	Clock for Serial Peripheral Interface	PA17
19	GND	Ground	GND
20	VCC	Power for extension board	VCC_P3V3

Figure 3-10. EXT2 Extension Header (J401) Schematic

Table 3-4. Extension Header 2 Pin Assignment
Pin Number	Pin Name	Description	GPIO
1	ID	Communication line to the ID chip on an extension board	-
2	GND	Ground	GND
3	ADC(+)	Analog-to-Digital converter, alternatively positive part of differential ADC	PA05
4	ADC(-)	Analog-to-Digital converter, alternatively negative part of differential ADC	PA06
5	GPIO1	General Purpose I/O	PA12
6	GPIO2	General Purpose I/O	PA13
7	PWM(+)	Pulse-Width Modulation, alternatively positive part of differential PWM	PA01
8	PWM(-)	Pulse-Width Modulation, alternatively negative part of differential PWM	PA02
9	IRQ/GPIO	Interrupt request line and/or general purpose I/O	PD08
10	SS/GPIO	Client select for SPI and/or general purpose I/O	PD09
11	TWD	Data line for I²C interface. Always implemented, bus type	PD01
12	TWCK	Clock line for I²C interface. Always implemented, bus type	PD00
13	RXD	Receiver line of target device UART	PB16
14	TXD	Transmitter line of target device UART	PB15
15	SS	Client select for SPI, should preferably be unique	PA14
16	MOSI	Host out Client in line of Serial Peripheral Interface	PA16
17	MISO	Host in Client out line of Serial Peripheral Interface	PA15
18	SCK	Clock for Serial Peripheral Interface	PA17
19	GND	Ground	GND
20	VCC	Power for extension board	VCC_P3V3