Building an electronic gadget from a kit is fun, but what once it is assembled? For many electronics enthusiasts, the real fun only begins when you can mod it. In this first Reverse Project article, we present a cheap FM radio receiver kit and a way to turn it into an Arduino-compatible, user-programmable device.

The RDA5807

The RDA5807 single-chip FM broadcast stereo radio tuner by RDA Microelectronics contains everything you need to build an FM broadcast receiver, including a stereo headphone output. An I²C interface is available for controlling the device and to extract information from it. To turn it into a usable radio, all you have to do is add an antenna, user controls, and, why not, a display.
 
Low-cost kits like the HU-017A RDA5807 Radio Kit are available that do precisely this. They take the RDA5807, add a microcontroller and other useful stuff (including an enclosure) and mold it into a small portable FM radio receiver.
 

The HU-017A RDA5807 Radio Kit

In this article, we take a close look at the HU-017A kit, how it works and what you can do with it. More interestingly though is that we also investigate ways to enhance the kit. There is room for improvement, because the kit doesn’t exploit the RDA5807 to its max. It can do much more than just tune to a station and adjust the volume. If only we could change its software for which we don’t have the source code…

From the solutions that are available to do this, we opted for replacing the microcontroller and turning the radio into an Arduino-compatible device. Thanks to the huge open-source community, writing new software is now easy. You are only limited by your imagination.

 

Reverse Project, a Series of Free Projects by Elektor

This article is the first of a hopefully long series entitled ‘Reverse Project’ about hacking and modding kits, a new initiative that is exclusively available to our e-zine readers. Enjoy!