Over at RCgroups, user [Cesco] has shared a very interesting project which uses the ever-popular ESP8266 as both a transmitter and receiver for RC vehicles. Interestingly, this code makes use of the ESP-Now protocol, which allows devices to create a mesh network without the overhead of full-blown WiFi. According to the Espressif documentation, this mode is akin to the low-power 2.4GHz communication used in wireless mice and keyboards, and is designed specifically for persistent, peer-to-peer connectivity.
Switching an ESP8266 between being a transmitter or receiver is as easy as commenting out a line in the source code and reflashing the firmware. One transmitter (referred to as the server in the source code) can command eight receiving ESP8266s simultaneously. [Cesco] specifically uses the example of long-range aircraft flying in formation; only coming out of the mesh network when it’s time to manually land each one.
[Cesco] has done experiments using both land and air vehicles. He shows off a very hefty looking tracked rover, as well as a quickly knocked together quadcopter. He warns the quadcopter flies like “a wet sponge”, but it does indeed fly with the ESP’s handling all the over the air communication.
To be clear, you still need a traditional PPM-compatible RC receiver and transmitter pair to use his code. The ESPs are simply handling the over-the-air communication. They aren’t directly responsible for taking user input or running the speed controls, for example.
This isn’t the first time we’ve seen an ESP8266 take the co-pilot’s seat in a quadcopter, but the maniacal excitement we feel when considering the possibility of having our very own swarm of flying robots gives this particular project an interesting twist.