How to Use Radiomaster ER8G 2.4GHz ELRS PWM Receiver: Examples, Pinouts, and Specs

The Radiomaster ER8G 2.4GHz ELRS PWM Receiver is a compact and lightweight receiver designed for use with ExpressLRS (ELRS) systems. Operating at a 2.4GHz frequency, it delivers reliable Pulse Width Modulation (PWM) output, making it ideal for controlling a variety of remote-controlled (RC) devices such as drones, RC cars, boats, and planes. Its low latency and high responsiveness ensure smooth and precise communication between the transmitter and the receiver.

• RC Aircraft: Provides precise control for fixed-wing planes and quadcopters.
• RC Cars and Boats: Ensures smooth throttle and steering control.
• Robotics: Enables wireless control of servo motors and actuators.
• Hobby Projects: Ideal for DIY RC systems and Arduino-based projects.

The Radiomaster ER8G receiver features a standard pin header for easy connection to servos, ESCs, or other devices. Below is the pinout:

1. Powering the Receiver:

   • Connect the VCC pin to a 5V-10V power source (e.g., a BEC or battery).
   • Connect the GND pin to the ground of your power source.

2. Connecting to Servos or ESCs:

   • Attach the PWM output pins (CH1-CH8) to the signal input pins of your servos, ESCs, or other devices.

3. Binding the Receiver:

   • Power on the receiver while holding the bind button (if available) or use the ELRS binding phrase configured in your transmitter.
   • Follow the binding procedure in your ExpressLRS transmitter module to establish a connection.

4. Configuring Channels:

   • Use your transmitter to assign functions (e.g., throttle, aileron, elevator) to the desired channels.

5. Testing:

   • Verify that all connected devices respond correctly to transmitter inputs before use.

• Antenna Placement: Ensure the antenna is positioned away from metal parts or other electronics to avoid signal interference.
• Voltage Range: Do not exceed the 10V input limit to prevent damage to the receiver.
• Firmware Updates: Keep the receiver's firmware updated to the latest version for optimal performance and compatibility with your transmitter.
• Failsafe Configuration: Set up failsafe behavior in your transmitter to ensure safe operation in case of signal loss.

The Radiomaster ER8G can be used with an Arduino UNO to read PWM signals. Below is an example code snippet:

// Example: Reading PWM signal from Channel 1 of the Radiomaster ER8G
// Connect CH1 to Arduino pin 2, and GND to Arduino GND.

const int pwmPin = 2;  // Pin connected to CH1
unsigned long pulseWidth;  // Variable to store pulse width

void setup() {
  pinMode(pwmPin, INPUT);  // Set pin as input
  Serial.begin(9600);  // Initialize serial communication
}

void loop() {
  // Measure the duration of the HIGH state of the PWM signal
  pulseWidth = pulseIn(pwmPin, HIGH);

  // Print the pulse width in microseconds
  Serial.print("Pulse Width: ");
  Serial.print(pulseWidth);
  Serial.println(" us");

  delay(100);  // Small delay for readability
}

1. Receiver Not Binding to Transmitter:

   • Ensure the transmitter and receiver are using the same ELRS firmware version.
   • Verify that the binding phrase or bind button procedure is correctly followed.
   • Check for proper power supply to the receiver.

2. No Response from Connected Devices:

   • Confirm that the PWM output pins are correctly connected to the devices.
   • Verify that the transmitter is configured to output signals on the correct channels.
   • Ensure the receiver is powered and bound to the transmitter.

3. Signal Interference or Dropouts:

   • Reposition the antenna to avoid obstructions or interference.
   • Reduce the transmitter's output power if operating in close proximity.

4. Receiver Overheating:

   • Check the input voltage to ensure it is within the 5V-10V range.
   • Avoid placing the receiver near heat-generating components.

Q1: Can I use the Radiomaster ER8G with a 3.3V power source?
A1: No, the receiver requires a minimum of 5V for proper operation.

Q2: How many devices can I connect to the receiver?
A2: You can connect up to 8 devices, one per PWM channel.

Q3: Is the receiver compatible with other protocols like DSMX or FrSky?
A3: No, the Radiomaster ER8G is specifically designed for the ExpressLRS protocol.

Q4: Can I use this receiver for telemetry?
A4: No, the Radiomaster ER8G is a PWM receiver and does not support telemetry features.

This concludes the documentation for the Radiomaster ER8G 2.4GHz ELRS PWM Receiver. For further assistance, refer to the official Radiomaster support resources.