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 3-4. The headers have a pitch of 2.54mm.
Table 4-1. 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 4-2. 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 4-3. 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 |
