Telemetry link between UAV (drone, airplane, boat) and laptop/mobile/ground station device can be very useful. Not only to get current drone position, altitude or battery level, but also, when wireless link provides such a possibility, to update drone parameters in-flight. Some radio links, like OpenLRS provides such a possibility out of the box. They include transparent serial bridge and almost any kind of device can use it to communicate with flight controller. Unfortunately, most RC radio systems lacks this functionality and additional telemetry links have to be used. Like SiK Telemetry Radio or 3DR commercial version of it.
One can buy or one can build something by his own. Some time ago I’ve chosen the second way and decided to build my own wireless serial link to archive 2 way communication between drone and ground station software. My objectives were:
- 433MHz since it is legal in my country
- has to allow to use my phone with EZ-GUI, since I do not like to carry my notebook to an airfield
- as cheap as possible
To satisfy those objectives I’ve decided as follows: