Introduction
This is a very full featured 16 channel Radio Control system for models of all kinds. I've been developing this project since Lockdown in May 2020, and it has grown steadily ever since — now with over 940 commits to the repository.
I and several friends have flown many models with it for over 6 years now, without any problem. It's proven to be as good as, and in some respects better than, popular commercially available radio control systems, as well as the other open source radio control firmware. In April 2025 the project was featured on Hackaday, bringing it to a worldwide audience of RC enthusiasts.
It is also far cheaper. Though I doubt that a really equivalent commercial system even exists. I estimate the cost to be only around £120 per transmitter, and around £35 per receiver depending on where you buy the components.
Technical Specifications
Hardware
- Transmitter: Teensy 4.1 microcontroller with ARM Cortex M7 (600 MHz)
- Receiver: Teensy 4.0 microcontroller
- Transmitter Transceiver: Ebyte ML01DP5
- Receiver Transceivers: Two ML01SP4s
- Display: Nextion NX8048P050 5" Capacitive touch screen
- Controls: FrSky M9 Hall Sensor Gimbals
- Digital Trims: FrSky X9D Plus transmitter parts
- Cases: 3D printed in PETG (or your preferred material)
Performance
- 16 Channels
- 50 Hz FHSS using 82 separate frequencies on 2.4 GHz ISM waveband
- 200 Hz frame rate for exceptionally low latency
- 12 BIT servo resolution
- Very small data packet size to reduce FHSS frequency collisions
- 11 PWM servo outputs with definable center points and frequencies
- Support for SBUS, PWM, and PPM
Key Features
- 90 model memories with almost unlimited backup file space on SD card
- 4 flight modes, each with its own curve for output
- 32 mixes (for inputs or outputs)
- 'Dual rates' (actually three rates available)
- Wireless Buddy Box for training beginners
- "AMS" (Automatic Model Selection) loads correct model memory automatically
- Buddy transmitter automatically loads the same model memory as Master
- Wireless model memory sharing between transmitters without removing SD cards
- Telemetry including battery voltage, GPS location, speed, altitude, heading, distance from home, etc.
- Speaker with critical voice messages and audio prompts
- User-defined Channel names, inputs and outputs
- 5-point curves for each channel and all four flight modes (straight, smoothed, and expo)
- Comprehensive failsafe protection
- 8 user-definable switches (four can be knobs for continuous variation)
- Digital trims, subtrim, servo reverse, servo speeds, user macros, motor timer, log files
- Support for third party transmitter modules (JR type)
- Context-sensitive help screens for all functions
- Variometer function for glider aircraft (audio and visual climb/sink rate)
- Enhanced telemetry support for Rotorflight 2.2/2.3 and Nexus flight controllers
- Nudge mode in wireless buddy box for precise beginner training
- Field-based PID and tuning value editing directly from the transmitter
Open Source Project
This repository contains not only the code for the transmitter, its screen and the receiver; but also the Gerber files for the printed circuit boards, the .STL files for the cases etc. and the text files for the help screens (to go onto the SD card). So there's nothing to stop anyone from building one.
Get Involved
If you would like to build one, I'll be happy to help. The repository includes full PCB Gerber files, STL files for 3D-printed cases, complete Bills of Materials, and the SD card help-screen text files — everything you need to get started.
Project Status
Active development continues, with new features added in response to requests from users and club flyers. With over 940 commits since 2020, the system is mature, stable, and flying regularly. The Hackaday feature in April 2025 brought interest from builders worldwide.
Photos
Photos coming soon
Videos
Videos coming soon