RadioMaster ERS-RC01 - CDI Gas Engine Tachometer for Compatible ExpressLRS PWM Receivers

The ERS-RC01 Gasoline Engine Tachometer measures RPM by connecting directly to your engine's CDI speed output. The sensor accurately detects engine speed, transmits the data to a compatible ExpressLRS receiver through the CRSF interface, and then sends it back to your EdgeTX radio for real-time monitoring. Ideal for any application requiring accurate RPM feedback.

As part of the ERS sensor family, the ERS-RC01 also supports pass-through expansion, allowing easy daisy-chaining with additional telemetry modules.

• Accurate Engine RPM: Monitors gasoline engine speed in real time with precision.
• ExpressLRS Integration: Sends RPM data directly to compatible ExpressLRS receivers via the CRSF interface.
• Versatile Applications: Ideal for any application requiring accurate RPM feedback.
• Compact & Lightweight: Easy to install without adding unnecessary weight.
• Plug-and-Play: Simple connection to the CDI output for fast setup.

• ER6 2.4GHz ExpressLRSPWM Receiver
• ER8 2.4GHz ExpressLRSPWM Receiver
• ER8G & ER8GV ExpressLRS PWM Receiver

Most PWM ExpressLRS receivers are fully compatible; those without a dedicated UART port require reconfiguration to support external sensors (e.g., for telemetry). To enable this, reassign two PWM output pins as a serial UART—one for TX and one for RX—via the receiver's Web UI (accessed by putting the receiver into WiFi mode) or via the ExpressLRS LUA script. This enables sensor connectivity while preserving the remaining PWM channels for servos or ESCs.

For receivers that only provide standard servo pins, an optional adapter cable is available that converts the sensor’s UART connector to two standard servo plugs (TX and RX). Available here: https://radiomasterrc.com/products/ers-sensor-uart-to-dual-pwm-adapter

Sensor Configuration & Telemetry Logging

To configure this sensor and view telemetry on your EdgeTX radio, install the RadioMaster Sensor Configurator LUA. The LUA allows adjustment of sensor settings, enables proper telemetry display, and supports data logging for post-flight review.

After downloading, connect your radio to a Mac or PC in USB-SD mode.

Copy the LUA files to:
/SCRIPTS/TOOLS/

👉Download the RadioMaster ERS Sensors Configurator.lua

• Item: ERS-RC01 RPM-CDI Sensor
• Operating voltage: 5–8.4V
• Operating current: 8mA
• Connector type: 3 pin
• Supported: CDI gasoline ignition
• Range: 200–300, 000RPM
• Accuracy: ±0.1%
• Temperature range: –10 ℃ to +85 ℃
• Size: 28 × 12 × 8mm
• Weight: 6.0g

• ERS-RC01 User Manual
• RadioMaster ERS Sensors Configurator.lua
• ERS Series Sensors Firmware V1.3

Weight

Package Includes

• 1 * ERS-RC01 RPM-CDI Sensor
• 3 * Heat-Shrinkable Tube
• 1 * Manual QR Code Card