For some insane reason, I decided to dive into the world of DIY drones by building my own transmitter and some would say the results were catastrophic. In the end, I learned a lot in the process and did successfully build a drone transmitter that actually works pretty well!

These instructions should have all the parts, materials, and 3d printed parts needed to build my transmitter, as well as the super simple receiver I made to pair with the transmitter. None of the steps are too difficult, so don’t be afraid to start!

Full build instructions can be found here:

https://www.modhobbyist.com/projects/26

RC Protocols

The hardest part of this project so far has been figuring out the best way to communicate from the RC Receiver to the flight controller.

Drones use two different communication protocols to operate, which are outlined very well by Oscar Liang here.

The way he puts it, the transmitter, or controller, sends a signal to the receiver mounted on the drone -- TX Protocols. Next, the receiver decodes that signal from the transmitter and sends it to the flight controller -- RX Protocols. In this project the TX protocol is easy, I'm using two Arduino Nano's to communicate via RF using NRF24L01 modules. Since I'm using Arduino Nano's and coding them myself, I make the TX protocol be whatever I want.

Now, I'm not an expert at RC protocols in any way, so the version of "TX Protocol" that I've implemented for this project is far from perfect, but it works...

The hard part is getting the receiving Arduino to successfully communicate with the drone. As outlined by Oscar Liang, there are several RX protocols to choose from, but the Arduino Nano isn't capable of doing them all. Currently, I am using PPM to communicate over a single wire to my flight controller, but in the future I hope to convert the RX Protocol to SBUS over UART. PPM works well but not all flight controllers support PPM, as I found when trying to locate one myself... On the other hand, most flight controllers have multiple UART channels that support SBUS.

Check out the build video on my channel!

https://www.youtube.com/c/modern-hobbyist

Good luck, and have fun!

Charlie