Open source software for autonomous unmanned systems

Spektrum remote (satellite) receiver

The Spektrum SPM9645 DSMX remote receiver by Horizon Hobby LLC is used as a C2 link receiver for piloted operation in many drone applications. This page contains relevant information and links.


Pin Color
Ground Black
+3.3 Volt Orange
Serial data Grey


For the Spektrum remote receiver the binding to a transmitter is usually performed by connecting it to a main receiver and then completing a normal binding process. In applications where the satellite receiver is used as the only receiver, this is not always practical though.

The Spektrum remote receiver is put into bind mode by sending a series of pulses on the serial data pin after power-up. This is documented in the Spektrum remote receiver interfacing document.

This video above shows how to bind the receiver as master using an Arduino Nano. Please notice that after connecting the power, the Spektrum orange LED starts flashing. After a successful binding process, the Spektrum LED turns solid orange. The open source software used to perform this bind is available at:

Serial data

During operation the output of the Spektrum remote receiver is a stream of serial data transmitted at a baudrate of 115,200. Please notice that the serial data pin uses 3.3 Volt logic levels. Below is a Python code example that reads the serial data stream and shows the output in a terminal.