DSM (digital spectrum modulation) is a relatively new radio control technology that is ideal for long-range applications. It uses two methods, FHSS (frequency hopping spread spectrum) and DSSS (direct sequence spread spectrum), to transmit data, with the latter being especially resilient to interference and therefore suitable for transmission over long distances. If you want to take advantage of DSM for your robotics projects, James Bruton designed an open source transmitter that you can build.

Bruton makes a lot of remotely operated robots, so he had a strong need for a good remote. His previous designs, while full of great features, didn’t have the kind of range that he wanted. So he created this new remote that incorporates DSM transmission technology. It contains two DSM transmitters to harness 20 individual channels. It uses those channels for four joysticks (each with three axes), four toggle switches, and four momentary push buttons. Together, those are enough to control even the most complicated robots.

Inside the remote’s 3D-printed enclosure is an Arduino Mega 2560 board. It monitors the various controls and outputs the data to a pair of OrangeRX 2.4GHz DSMX transmitters. It also outputs the battery voltage to a small three-digit, seven-segment display. Power comes from four 18650 lithium battery cells. This remote will work with any compatible DSM receiver, which are affordable and easy to integrate into a project, as they operate like a standard RC receiver.