How to Use ELRS Lite RX: Examples, Pinouts, and Specs

The ELRS Lite RX by BetaFPV is a compact and lightweight receiver module designed for long-range (LR) remote-controlled (RC) applications. It utilizes the open-source ExpressLRS (ELRS) protocol, which is known for its high performance and low latency communication. This receiver is ideal for use in radio-controlled aircraft, drones, and other vehicles where reliable long-range communication is essential.

• Remote control aircraft and drones
• Long-range RC boats
• Robotics and unmanned vehicles
• FPV (First Person View) racing and casual flying

• Frequency Bands: 2.4GHz ISM
• Protocol: ExpressLRS
• Output Power: Up to 100mW
• Input Voltage: 5V
• Telemetry: Yes, with power and signal strength indication
• Antenna Connector: IPEX / u.FL
• Firmware: Updatable via BetaFPV configurator

1. Power Supply: Connect the 5V and GND pins to a stable 5V power source.
2. UART Connection: Connect the TX and RX pins to the corresponding UART RX and TX pins on your flight controller.
3. Telemetry: If telemetry is desired, connect the S.Port pin to a telemetry-capable UART on your flight controller.
4. Antenna: Attach the antenna to the IPEX/u.FL connector, ensuring it is secure and positioned for optimal signal reception.
5. Binding: Follow the manufacturer's instructions to bind the ELRS Lite RX with your ELRS-compatible transmitter.

• Ensure the antenna is properly installed and not obstructed for maximum range.
• Avoid placing the receiver next to high-power components to minimize interference.
• Update the firmware regularly to benefit from improvements and bug fixes.
• Use a capacitor to filter power supply noise if necessary.

• Binding Issues: Ensure both the transmitter and receiver are on the same firmware version.
• Range Problems: Check the antenna placement and ensure there are no obstructions or sources of interference.
• Telemetry Not Working: Verify the telemetry connection and ensure the flight controller is configured correctly.

• Firmware Mismatch: Update both the transmitter module and receiver to the latest compatible firmware.
• Poor Range: Reposition the antenna, check for damage, or consider using a higher gain antenna.
• Telemetry Configuration: Double-check the port configuration in your flight controller's software to ensure telemetry is enabled.

#include <SoftwareSerial.h>

SoftwareSerial mySerial(10, 11); // RX, TX

void setup() {
  // Start the hardware serial communication
  Serial.begin(9600);
  
  // Start the software serial communication
  mySerial.begin(9600);
  
  // Print a message to the serial monitor
  Serial.println("ELRS Lite RX Example");
}

void loop() {
  // Check if data has been received from the receiver
  if (mySerial.available()) {
    // Read the data and print it to the serial monitor
    Serial.print("Received: ");
    Serial.println(mySerial.read());
  }
  
  // Check if data has been received from the serial monitor
  if (Serial.available()) {
    // Send the data to the receiver
    mySerial.write(Serial.read());
  }
}

Note: This example uses SoftwareSerial to create a serial connection on pins 10 and 11 of the Arduino UNO. The ELRS Lite RX should be connected to these pins for the example to work. Adjust the baud rate as necessary to match the ELRS Lite RX configuration.

Remember to consult the BetaFPV documentation for specific instructions on binding and configuring the ELRS Lite RX with your transmitter and flight controller.