The ATmega324PB
Xplained Pro headers EXT1, EXT3, and
EXT4 offers access to the I/O of the microcontroller in order to expand the board e.g.,
by connecting extensions to the board. These headers are based on the standard extension
header specified in Table 1. The headers have a pitch of 2.54mm.
Table 1. Extension Header EXT1| EXT1 pin |
ATmega324PB pin |
Function |
Shared functionality |
|---|
| 1 [ID] |
- |
- |
Communication line to the ID chip on an extension
board |
| 2 [GND] |
- |
- |
Ground |
| 3 [ADC(+)] |
PA0 |
ADC0/Y0 |
|
| 4 [ADC(-)] |
PA1 |
ADC1/Y1 |
|
| 5 [GPIO1] |
PA2 |
ADC2/Y2 |
|
| 6 [GPIO2] |
PA3 |
ADC3/Y3 |
|
| 7 [PWM(+)] |
PD5 |
TC1-OCA/X5 |
|
| 8 [PWM(-)] |
PD4 |
TC1-OCB/X4 |
|
| 9 [IRQ/GPIO] |
PC1 |
TW0-SDA/X11 |
EDBG GPIO2 |
| 10 [SPI_SS_B/GPIO] |
PC0 |
TW0-SCL/X10 |
|
| 11 [TWI_SDA] |
PE5 |
TW1-SDA |
EXT1/3/4/EDBG I2C |
| 12 [TWI_SCL] |
PE6 |
TW1-SCL |
EXT1/3/4/EDBG I2C |
| 13 [USART_RX] |
PD0 |
U0-RXD |
|
| 14 [USART_TX] |
PD1 |
U0-TXD |
|
| 15 [SPI_SS_A] |
PB4 |
S0-SS |
EDBG GPIO0 |
| 16 [SPI_MOSI] |
PB5 |
S0-MOSI |
EXT1/3/4/EDBG SPI |
| 17 [SPI_MISO] |
PB6 |
S0-MISO |
EXT1/3/4/EDBG SPI |
| 18 [SPI_SCK] |
PB7 |
S0-SCK |
EXT1/3/4/EDBG SPI |
| 19 [GND] |
- |
- |
Ground |
| 20 [VCC] |
- |
- |
Power for extension board |
Table 2. Extension Header EXT3| EXT3 pin |
ATmega324PB pin |
Function |
Shared functionality |
|---|
| 1 [ID] |
- |
- |
Communication line to the ID chip on an extension
board |
| 2 [GND] |
- |
- |
Ground |
| 3 [ADC(+)] |
PC5 |
|
Analog header and EDBG JTAG TDI via J200 |
| 4 [ADC(-)] |
PC7 |
|
USER LED |
| 5 [GPIO1] |
PE4 |
GPIO/AREF |
EXT4.8 |
| 6 [GPIO2] |
PC2 |
GPIO |
EDBG JTAG TCK via J200 |
| 7 [PWM(+)] |
PC4 |
TC4-OCA |
EDBG JTAG TDO via J200 |
| 8 [PWM(-)] |
PC3 |
GPIO |
EDBG JTAG TMS via J200 |
| 9 [IRQ/GPIO] |
PC6 |
GPIO |
USER BUTTON/EDBG GPIO3 |
| 10 [SPI_SS_B/GPIO] |
PB1 |
GPIO |
|
| 11 [TWI_SDA] |
PE5 |
TW1-SDA |
EXT1/3/4/EDBG I2C |
| 12 [TWI_SCL] |
PE6 |
TW1-SCL |
EXT1/3/4/EDBG I2C |
| 13 [USART_RX] |
PD2 |
U1-RXD |
EDBG CDC |
| 14 [USART_TX] |
PD3 |
U1-TXD |
EDBG CDC |
| 15 [SPI_SS_A] |
PD6 |
SPI-SS |
|
| 16 [SPI_MOSI] |
PB5 |
S0-MOSI |
EXT1/3/4/EDBG SPI |
| 17 [SPI_MISO] |
PB6 |
S0-MISO |
EXT1/3/4/EDBG SPI |
| 18 [SPI_SCK] |
PB7 |
S0-SCK |
EXT1/3/4/EDBG SPI |
| 19 [GND] |
- |
- |
Ground |
| 20 [VCC] |
- |
- |
Power for extension board |
Table 3. Extension Header EXT4| EXT4 pin |
ATmega324PB pin |
Function |
Shared functionality |
|---|
| 1 [ID] |
- |
- |
Communication line to the ID chip on an extension
board |
| 2 [GND] |
- |
- |
Ground |
| 3 [ADC(+)] |
PA4 |
ADC4 |
|
| 4 [ADC(-)] |
PA5 |
ADC5 |
|
| 5 [GPIO1] |
PA6 |
ADC6 |
|
| 6 [GPIO2] |
PA7 |
ADC7 |
EDBG SPI SS via strap J201 |
| 7 [PWM(+)] |
PB3 |
TC0-OCA/AIN1 |
ANALOG header |
| 8 [PWM(-)] |
PE4 |
AREF |
EXT3.5 |
| 9 [IRQ/GPIO] |
PB2 |
INT2/PC1-10 AIN0 |
EDBG GPIO1/ANALOG header |
| 10 [SPI_SS_B/GPIO] |
PD7 |
TC2-OCA |
|
| 11 [TWI_SDA] |
PE5 |
TW1-SDA |
EXT1/3/4/EDBG I2C |
| 12 [TWI_SCL] |
PE6 |
TW1-SCL |
EXT1/3/4/EDBG I2C |
| 13 [USART_RX] |
PE2 |
U2-RXD |
|
| 14 [USART_TX] |
PE3 |
U2-TXD |
|
| 15 [SPI_SS_A] |
PB0 |
SPI SS |
|
| 16 [SPI_MOSI] |
PB5 |
S0-MOSI |
EXT1/3/4/EDBG SPI |
| 17 [SPI_MISO] |
PB6 |
S0-MISO |
EXT1/3/4/EDBG SPI |
| 18 [SPI_SCK] |
PB7 |
S0-SCK |
EXT1/3/4/EDBG SPI |
| 19 [GND] |
- |
- |
Ground |
| 20 [VCC] |
- |
- |
Power for extension board |