“Use a couple of packet radio boards to mirror one robot’s movements in the other one from up to 500m away.
The idea of having a large number of robots doing tasks in unison is nothing new, as there have been quadcopters drawing designs with LEDs at events like the Sochi Olympics, and convoys of trucks all moving together. What I wanted to do with this project was explore how this could be accomplished using cheap hardware and at greater distances apart, since Bluetooth can only reach about 45m away before the signal becomes too weak.
Packet Radio Principles of Operation
The Adafruit Feather M0 used for this project contains an onboard RFM69 radio module, and it can operate in one of two modes. The first one is a continuous stream of data from one point to the other, much like how a pair of walkie-talkie radios would function. This can lead to a lot of data being missed or corrupted, and it’s more difficult to build an application layer on top of it.
The other way to operate the radio module is packet mode, which collects a buffer of data and sends it in a packet, akin to how the UDP protocol works. This way, information can be encrypted and checked for errors, making information transfer more reliable. Once the packet is sent, the receiver sends an acknowledgement to the sender that indicates a successful transference.”