Firmware for ESP32-C3, ESP32-S3, and similar microcontrollers, enabling telemetry broadcast from Crossfire and ELRS radio systems over Bluetooth or Wi-Fi.
- Transmits Crossfire/ELRS telemetry from RC transmitters to phones, tablets, or laptops via Bluetooth or Wi-Fi
- Compatible with transmitters using Aux-serial output as well as direct connection to internal modules (e.g. Jumper RC up to T15)
- Telemetry display supported via TelemetryViewer, WebTelemetry, or the built-in web interface
Development boards ESP32-C3-SuperMini (recommended) or ESP32-S3-SuperMini. Other ESP32-based boards with BLE and Wi-Fi support may also work, but compatibility is untested and not guaranteed.
These boards are compact, affordable, and free from unnecessary components. If using a different ESP32-C3 or ESP32-S3 board, note that pin numbering may differ from the microcontroller's internal pin numbers. Refer to your board’s datasheet to identify correct pin mappings.
The module connects to the transmitter’s SerialAUX interface using 4 wires:
- 5V
- GND
- TX → to pin 3 (module RX)
- RX → to pin 4 (module TX)
Wiring to a RadioMaster Pocket transmitter example
If the transmitter lacks SerialAUX, connect the ELRS/Crossfire internal module’s TX pin directly to the module’s RX (pin 3).
Connection to internal TX on a Jumper T20 transmitter example
Flash the firmware using the Web Configurator (for legacy versions). BLE mode configuration is also done through the same interface.
Switch between BLE and Wi-Fi modes by pressing the Boot button on the module.
In Wi-Fi mode, connect to the BLE Telemetry Lite access point using the password: 12345678. The web interface is accessible at http://192.168.4.1.
This repository's source code is available under the MIT License.