RAKwireless IO Extension Module RAK5804

The RAK5804 connects to a WisBlock Core module, such as the RAK4631, via its two 10-pin expansion connectors (J2 and J3). Simply align the board and press it onto the core's matching headers. Ensure the USB port on the RAK5804 is accessible for programming. The module is powered directly from the 3.3V supply provided by the WisBlock Core through these connectors, requiring no external power setup.

The USB interface on the RAK5804 provides direct serial communication access to the connected WisBlock Core module. This allows you to program the core's microcontroller (e.g., an nRF52840) via USB from your computer using Arduino IDE or other development tools, as well as establish a serial monitor connection for debugging logs and sending AT commands without needing a separate debug probe.

No, the analog input on the RAK5804 is designed for a 3.3V logic level and measurement range. Applying a voltage higher than 3.3V can damage the input pin and potentially the entire module. Always ensure your analog sensor's output is compatible with 3.3V levels. For sensors with higher output, use a resistive voltage divider circuit to scale the signal down to the safe 0-3.3V range before connecting it.

The RAK5804 provides two I2C ports, which can be used to create separate I2C buses or to daisy-chain devices. Connect your I2C sensors to the SDA and SCL pins of your chosen port, ensuring you include pull-up resistors (typically 4.7kΩ) to 3.3V on each line if not already present on the sensor board. In your firmware (Arduino, PlatformIO), initialize the corresponding I2C peripheral and scan for device addresses to communicate with your sensors.