Dilshan R Jayakody’s Web Log

RDS ( Radio Data System ) is a communication protocol standard used for embedding small amounts of digital information in traditional FM radio broadcasts. It enables radio stations to transmit data such as station identification, program information, and traffic updates.  To capture and decode RDS data, one method involves using a Software Defined Radio (SDR) along with GNU Radio and RFtap . GNU Radio provides a framework for creating software radios, while RFtap acts as a bridge between GNU Radio and conventional network monitoring and packet analysis tools like Wireshark . Decoding RDS data using Wireshark. Unfortunately, as of the time of writing, RFtap is no longer being maintained and does not work with the latest version of GNU Radio (version 3.10.10). This post offers guidelines for rebuild and using RFtap with the new GNU Radio release. This post assumes that the reader has access to DVB-T dongles based on the Realtek RTL2832U and a PC running Ubuntu or Debian Linux. For ...

The QN8035 is a stereo FM radio receiver launched by the Quintic Corporation . Compared to other popular digital FM tuners ( RDA5807 , TEA5767 , etc.), this tuner does not seem to be as popular among the DIY community. As we have seen, the biggest problem with this IC is the lack of information. During our initial search, we came across some details about this IC. Much of that information was confined to a product datasheet and a few undocumented GIT repositories. Based on the information we found on the internet, we concluded that Quintic was no longer in business. According to the NXP website , it stated that Quintic Corporation was acquired by NXP in 2015.  Although the Quintic is no longer in business, the QN8035 IC can still be purchase at a low price from online stores. In addition, we found several FM radio kits manufactured using this IC in online stores. Due to the lack of information, I decided to explore this IC to understand its functionality and limitations. In t...

This tuner circuit is a quick prototype which I build to test the RDA5807M FM radio tuner IC. RDA5807M is a single-chip tuner IC with RDS and MPX decoder, and it equipped with I 2 C interface for control. The main reason to build this prototype is to understand the behavior of this chip. The prototype version of the RDA5807M receiver. At the time of this design, the website of the RDA microelectronics is not accessible from my location. Because of this reason, I download different versions of RDA5807M datasheets from the internet. While going-through those datasheets, I observed that it comes with limited information. Finally, I decided to build this receiver to verify some of those parameters and to review the RDS functionality of the chip. I build this receiver around ATmega16A MCU. I choose this MCU because I got a few of ATmega16A MCUs in my inventory and also due to the higher number of  I/O pin count. RDA5807M module. In this design, the volume is contro...