RadioMaster ERS-CU01 – Real-Time Current Sensor for compatible ExpressLRS PWM Receivers

The ERS-CU01 Current Sensor is a compact telemetry module for use with compatible ExpressLRS  receivers. Installed inline between the battery and ESC, it measures real-time operating current and voltage sending the data through the ExpressLRS receiver for display on your EdgeTX radio. This provides instant insight into system load, efficiency, and power consumption across your entire powertrain.

As part of the ERS sensor family, the ERS-CU01 also supports pass-through expansion, allowing easy daisy-chaining with additional telemetry modules. 

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Plug and Play Compatible Receivers:

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

Features:

• Real-Time Current Monitoring: View live current draw and voltage directly on your radio to better understand system performance and prevent overload conditions.
• Inline Installation: Soldered between the battery and ESC for accurate, full-system current measurement.
• Future-Ready Pass-Through: Includes in-and-out ports for daisy-chaining additional ERS sensors as your telemetry needs grow.
• Seamless ExpressLRS Integration: Designed to work smoothly with compatible ExpressLRS PWM receivers.

Specifications:

• Item: ERS-CU01 Current Sensor
• Operating voltage: 5–8.4V
• Operating current: 22mA
• Current range: 1–150A
• Max voltage: 70V
• Current accuracy: ±0.5A
• Voltage accuracy: ±0.1V
• Continuous current: 100A
• Temperature range: –10 ℃ to +85 ℃
• Size: 30 × 25 × 10.5mm
• Weight: 20.6g

Using Sensors with Non-Plug-and-Play PWM ExpressLRS Receivers:

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).

Package Includes:

• 1 * ERS-CU01 Current Sensor
• 3 * Heat-Shrinkable Tube
• 1 * Manual QR Code Card