Reyax RYS8833 Ultra Low Power 1.8V UART/I2C GNSS Module

The Reyax RYS8833 module supports both UART and I2C interfaces, selectable via configuration commands or hardware pin strapping. For UART mode, connect the TX/RX pins to your microcontroller's serial port with a default baud rate typically set to 9600 or 115200 bps. For I2C mode, connect the SDA and SCL pins to your host controller's I2C bus, ensuring proper pull-up resistors are present. Refer to the RYS8833 datasheet for the specific command set to switch between interface protocols and configure the baud rate or I2C address.

To achieve the specified 3.7mA idle current, ensure your power supply provides a stable voltage within the 0.9V to 1.95V range. Implement power cycling strategies in your firmware, placing the module into periodic sleep or standby modes between position fixes. Use the module's built-in power management commands to disable unused constellations or reduce update rates. For lowest system current, design your voltage regulator to be highly efficient at low loads and consider using a direct Li-ion or 2xAA battery connection if within the voltage spec.

The RYS8833 outputs standard NMEA sentences over its serial interface, compatible with common GNSS libraries like TinyGPS++ or NeoGPS for the Arduino IDE. For ESP32 integration, you can use the HardwareSerial library to parse NMEA data or implement custom I2C communication if configured. No proprietary driver is required; the module communicates via AT-like commands for configuration. For advanced use cases, you can develop custom drivers in ESP-IDF or PlatformIO to manage power modes, multi-constellation selection, and raw data logging.