2026-09-13 –, Freiraum - C120 Language: English
Modern radios often use firmware in order to control the radio hardware.
We will take a look at one such device and how to run our own firmware on it.
There are a lot of radios available for the commercial market that also support frequencies in the amateur radio bands. In spite of this, however, their firmware is not designed for ham radio use. By running our own firmware, like OpenRTX, is possible to overcome the usability limitations of the original firmware and add new features beyond the original design.
OpenRTX is an open-source firmware for radios. It was started in 2020 by a group of Italian amateur radio operators. It is designed to be modular and allows new ways to experiment with existing hardware.
We will be taking a closer look at how to port this firmware to a new device.
It all starts with gathering information about the device we want to run our firmware on. This includes the specific components used, how they are connected and how the device is normally updated. We will show how each step can be accomplished in multiple ways.
OpenRTX, the firmware we want to run on the device, assumes a POSIX interface. For most targets miosix, an operating system for micro controllers, is used. Having an operating system allows us to only implement a few basic drivers to get started.
We will start with a driver for the GPIOs as this will allow us to see that our code is executed by blinking an LED. From there we can continue with implementing more drivers to get to a working device.
You can find more about OpenRTX on the website: https://openrtx.org
working as a software engineer by day
In my free time I like to hack on radios for amateur radio use. I do not transmit a lot, but when I do it is usually for TOTA(Toilets on the Air) at Chaos events.