GPIO
Description of the GPIO header.
Last updated
Description of the GPIO header.
Last updated
Free Wil-i includes a GPIO pin header for interacting with digital protocols. This GPIO header is flexible, allowing varying voltage levels and IO direction. The pin-out and connector are shown below.
The IO voltage levels are shared by all the GPIO. To set the voltage level you must inject a voltage on PIN4. This voltage can be set to 3.3v or 5.0v with a jumper. This would be a jumper between pins 2 and 4 for 5V. Or between 4 and 6 for 3.3V.
The table below describes the pins. All GPIO except dedicated I2C pins can be used bidirectionally depending on the application. So the directions are the default.
1
SPI Chip Select Out
Output
2
5V Out
Output
5V to power IO and external circuit
3
GPIO27 OUT
Output
RPi 2040 GPIO27
4
V PINS IN
Input
Input to set the IO voltage 1.1 to 5.5V
5
UART1 Rx IN
Input
RPi 2040 UART 1 Receive (GPIO9)
6
3.3V Out
Output
3.3 V to Power IO and external circuit
7
UART1 CTS IN
Input
RPi 2040 UART 1 Clear To Send (GPIO10)
8
I2C0 SCL
In/Out
RPi 2040 I2C 0 Clock (GPIO17)
9
UART1 TX OUT
Output
RPi 2040 UART1 Transmit (GPIO8)
10
I2C0 SDA
In/Out
RPi I2C 0 Data (GPIO16)
11
UART1 RTS OUT
Output
RPi 2040 UART 1 Request To Send (GPIO11)
12
SPI1 RX IN
Input
RPi 2040 SPI 1 Receive (GPIO12)
13
SPI1 TX OUT
Output
RPi 2050 SPI 1 Transmit (GPIO15)
14
GPIO 26 IN
Input
RPi 2040 GPIO26
15
SPI1 SCLK OUT
Output
RPi 2040 SPI 1 Clock (GPIO14)
16
SWCLK IN
Input
RPi 2040 debugger clock input for external SWD debugger.
17
GPIO25 OUT
Output
RPi 2040 GPIO25. GPIO25 also connects to board status LED (same as RPi Pico)
18
SWDIO
In/Out
RPi 2040 debugger IO for external SWD debugger.
19
GND
20
GND
The I2C interface is connected to the RPi I2C0 peripheral. The I2C Interface uses the chip PCA9517 for buffering. Please see the data sheet below for details.
All the GPIO that is not I2C uses the sn74lxc1t45 for buffering.
