Tlrs-Let's make a long-distance telemetry system together

who I am?

I’m an electrical engineer from makeflyeasy, an Ardupilot supporter, and a drone fanatic.

Problems encountered

I often use telemetry on the fixed wing to detect the attitude information of the aircraft, and I encountered 2 difficult problems when using the 3DR radio.

  • 3DR radio is based on Sik open source firmware, and the mainstream supports Si1000, which is difficult to buy at present.
  • The actual flight test distance of 3DR radio is usually only a few hundred meters.

Birth an idea

I want to do a telemetry to achieve the following functions:

  • Based on Sik firmware development, it is convenient to configure parameters in the Mission Planner ground station software
  • Main control STM32F103 series, RF module Si4463, using conventional chips, easy to purchase, cost-effective
  • Support 915/868 MHz, do not use 2.4G, mainly for fixed-wing mountain flight, the signal diffraction ability is too poor
  • Mainly support Mavlink complete data package, support PPM/SBUS 16 RC channels
  • Both software and hardware are open source and can be merged into AP_Periph in the future to benefit more drone enthusiasts

What can be done:

  • Design schematics and PCB files, deliver proofing for production
  • Component procurement, welding, hardware debugging
  • Write a transparent transmission test program to detect basic functions and interfaces

Main challenges:

  • I am not familiar with Sik, it may take a long time to complete the port development
    *Sik firmware stability test takes a long time


  • Currently named TLRS, “T” stands for Together, I hope to gather the power of open source to complete this challenge together!

  • If there are drone enthusiasts who are good at Sik firmware development, welcome to join, I can provide a hardware development platform for free to facilitate software development and testing

Special thanks to!

I decided to start this project because I couldn’t find an LRS that would meet my fixed wing needs. I am very grateful for the thought inspiration provided by other open source LRS projects, listed below to express my gratitude!

Contact information


Si4463 RF module, I chose E30-900M20S and E30-900M30S with SPI interface.



AndrewTridgell has done some compatible work on the Si4463 before, and I’m posting the link below:

thanks for this! I think it is a great idea

I already ported the SiK firmware to teensy and added sbus support. Using a 10 usd teensy could help overcome chip shortages and using 4.0 version will add enormous set of hw features and processing capability.

Thank you for the information, very useful!