There are 4 available IO expansion headers on the kit. Some pins have shared functionality with onboard functionality. If "clean" expansion ports are needed, there are available cut-straps on some of the ADC inputs to remove onboard functionality. Tables below show what is shared on the header pins.
| Pin | J1 | UC3 pin | Shared with onboard functionality |
|---|---|---|---|
| 1 | TWI0 SDA | PA25 | - |
| 2 | TWI0 SCL | PA26 | - |
| 3 | USART3 RXD | PX57 | - |
| 4 | USART3 TXD | PX58 | - |
| 5 | SPI1 CS0 | PB09 | - |
| 6 | SPI1 MOSI | PB10 | - |
| 7 | SPI1 MISO | PB08 | - |
| 8 | SPI1 SCK | PB07 | - |
| 9 | GND | - | - |
| 10 | VCC_P3V3 | - | - |
| Pin | J2 | UC3 pin | Shared with onboard functionality |
|---|---|---|---|
| 1 | ADC0 | PA21 | RC filter output |
| 2 | ADC1r | PA22 | NTC |
| 3 | ADC2 | PA23 | - |
| 4 | ADC3 | PA24 | - |
| 5 | ADC4 | PA20 | - |
| 6 | ADC5 | PA19 | - |
| 7 | ADC6 | PA18 | - |
| 8 | ADC7 | PA17 | - |
| 9 | GND | - | - |
| 10 | VCC_ANA_P3V3 | - | - |
| Pin | J3 | UC3 pin | Shared with onboard functionality |
|---|---|---|---|
| 1 | GPIO0 | PA31 | - |
| 2 | GPIO1 | PA30 | - |
| 3 | GPIO2 | PA29 | - |
| 4 | GPIO3 | PA28 | - |
| 5 | GPIO4 | PA27 | - |
| 6 | GPIO5 | PB00 | - |
| 7 | GPIO6 | PB11 | - |
| 8 | GPIO7 | PX19 | - |
| 9 | GND | - | - |
| 10 | VCC_P5V02 | - | - |
| Pin | J4 | UC3 pin | Shared with onboard functionality |
|---|---|---|---|
| 1 | TWI1 SDA | PA15 | USART1 CTS |
| 2 | TWI1 SCL | PA14 | USART1 RTS |
| 3 | USART1 RXD | PA05 | - |
| 4 | USART1 TXD | PA06 | - |
| 5 | SPI0 CS3 | PA07 | - |
| 6 | SPI0 MOSI | PA10 | Serial flash |
| 7 | SPI0 MISO | PA11 | Serial flash |
| 8 | SPI0 SCK | PA08 | Serial flash |
| 9 | GND | - | - |
| 10 | VCC_P3V3 | - | - |
ADC channels can be disconnected from onboard functions by cutting the available cut-straps on the bottom side of the board
The VCC pin on this header has 5V and is connected to the USB power