ExpressLRS PWM Receiver Setup and Configuration Guide

ExpressLRS PWM receivers provide direct PWM output for controlling servos and ESCs without external converters. This guide offers a concise setup process, key settings, and troubleshooting tips for models like ER3C-i, ER5C-i, ER4, ER6, ER8, ER6G, ER6GV, ER8G, ER8GV, ER5A, ER5A V2, ER5C, and ER5C V2.

Introduction

ExpressLRS PWM receivers simplify RC control by delivering direct PWM output, supporting flexible channel mapping, failsafe settings, and various output modes. This article walks you through configuring your receiver for RC planes, cars, or boats using the WebUI.

Setup Guide

Step 1: Power On and Enter WiFi Mode

  • Power the receiver and wait for it to enter WiFi mode (LED blinks).

  • Connect to the WiFi network (SSID: ExpressLRS RX, password: expresslrs) using a phone or laptop.

Step 2: Access the WebUI

  • Open a browser and go to 10.0.0.1.

  • Navigate to the Model tab to adjust settings.

Step 3: Configure Channel Mapping

  • Default mapping: TX Channel 1 to PWM Output 1, Channel 2 to Output 2, etc.

  • Remap channels in the WebUI (e.g., CH1 to multiple outputs or adjust AUX1/CH5 for higher resolution).

  • Save and verify settings.

Step 4: Set Failsafe Values

  • Set values between 988us and 2012us per channel (default: 1500us, except Output 3 at 988us).

  • Assign safe positions (e.g., throttle to 988us for disarm).

  • Failsafe triggers if Link Quality (LQ) is 0 or no valid packet is received for 1 second.

Step 5: Choose PWM Frequency and Output Mode

  • Select frequency: 50Hz (servos), 100Hz–400Hz (ESCs), or DSHOT300 (ESP32 receivers).

  • For serial output (CRSF/SBUS), configure in the Model tab and use dedicated ports or remapped pins.

Step 6: Test Your Setup

  • Test outputs for correct operation.

  • Adjust mappings or failsafe values if needed, then retest.

Key Settings

Channel Resolution

  • CH1–CH4: 10-bit full resolution.

  • CH5–CH12: Switch channels with lower resolution. Enable Wide Switch Mode for 7-bit (128 positions) resolution.

Supported Output Modes

  • PWM Frequencies: 50Hz, 60Hz, 100Hz, 160Hz, 333Hz, 400Hz.

  • Pulse Widths: Normal (988–2012us), extended (885–2115us), half (494–1006us).

  • Additional Modes: DSHOT300, serial protocols (CRSF, SBUS), 10kHz Duty Cycle PWM, Binary On/Off.

Failsafe Configuration

  • Set via WebUI. No pulses generated until the transmitter connects, aiding ESC calibration.

Advanced Features

Serial Output

  • Configure CRSF or SBUS on dedicated ports (e.g., ER6, ER8) or remap pins via the WebUI’s hardware.html page.

Multiple Receivers

  • Bind multiple receivers to one controller for extra channels (e.g., 16+ outputs).

  • Assign unique channel outputs to each receiver.

Telemetry

  • Models like ER6 and ER8 support VBAT telemetry (up to 35V). Calibrate in your radio settings.

Troubleshooting

  • Unexpected Failsafe: Verify channel mappings and failsafe settings. Check for interference or loose connections.

  • WiFi Mode Failure: Power cycle the receiver. Reflash firmware if the issue persists.

  • No Serial Output: Confirm protocol and pin settings in WebUI. Use dedicated ports where available.

  • Lost Configuration: Reapply settings via WebUI (preferred over Lua script for stability).

Conclusion

Configuring your ExpressLRS PWM receiver is straightforward with the WebUI. Map channels, set failsafe values, and select output modes to suit your needs. Test your setup thoroughly and refer to the ExpressLRS documentation for further assistance.

Next Steps: Test your configuration and adjust as required for optimal RC performance!