3.3.1 Pin Definitions and Applications
The development board features an expansion pin header to facilitate peripheral expansion for users. Please refer to this section for interface definitions.
Pin Multiplexing Configuration (Deprecated)
To be updated
Expansion Pin Header Definition
The RDKS100 provides a 40-pin header for user peripheral expansion, with digital I/O pins designed for 3.3V logic levels. The pinout is defined as follows:
Pins labeled as 40PIN_GPIO[x]_3V3 in the pinout are GPIOs provided by an I2C-expander IC. These pins are not managed by the SoC's Pinctrl controller, cannot be multiplexed to other functions, do not require Pinmux configuration in the device tree source (DTS), and can only be used as GPIOs.
GPIO Read/Write Operation Example
The pins mentioned below are for illustrative purposes only. Port numbers may vary across different platforms—please verify against your actual hardware. Alternatively, you can directly use the code under the /app/40pin_samples/ directory, which has been validated on the actual board.
The development board includes pre-built functional test scripts for various pins under /app/40pin_samples/, covering GPIO input/output, PWM, I2C, SPI, UART, and more. All test programs are written in Python; refer to other sections of this chapter for detailed information.
Take /app/40pin_samples/button_led.py as an example: this script configures pin 24 as an input and pin 23 as an output, then controls the output state of pin 23 based on the input state of pin 24.
Environment Setup
Use a Dupont jumper wire to connect pin 24 to either 3.3V or GND to control its logic level (high or low).
Execution Method
Run the button_led.py script to start the GPIO read/write program:
root@ubuntu:~# cd /app/40pin_samples/
root@ubuntu:/app/40pin_samples# sudo python3 ./button_led.py
Expected Behavior
By toggling the logic level of pin 24, you can change the output level of pin 23.
root@ubuntu:/app/40pin_samples# ./button_led.py
Starting demo now! Press CTRL+C to exit
Outputting 1 to Pin 23
Outputting 0 to Pin 23
Outputting 1 to Pin 23