MY DAB+ radio !
It has now been over 12 years since I built the Elektor DSP radio which used the Si4735 chip from Silicon Labs (now Skyworks). This was the first time an FM radio was built using a DSP circuit to receive and decode RDS from an FM station.
I wanted to reissue this radio by adapting it to the new DAB+ radio standard.
In my area, I receive more than 80 DAB stations perfectly with excellent sound quality.
So I turned to the "successor" of the Si4735 chip which is called Si4684.
I used a card integrating the SI4684 chip from AVIT Research.
I programmed the application on an ESP32 Wroom-32D processor (ESPRESSIF''s ESP32 Dev kit).
I connected a color TFT screen and an 82C256 EEPROM linked to the I2C bus.
The user interface uses 7 keys.
I wrote a complete software to manage FM and DAB+, including full station name management (both FM and DAB+) allowing sorting and alphabetical display of stations.
Therefore, the selection of the different stations is very pleasant, without any dead time in the display, and the HMI interface is very reactive.
A lot of information is displayed in real time (Intensity and quality of the frequency signal, automatically updated time, etc.).
The sound quality is there, and on my prototype I even added two small class D amps with an output power of 3W RMS. Bluffing when plugged into good speakers!
Do not hesitate to reproduce my prototype and be sure to use the latest version of the software (currently april-2023 version 1.70) because many improvements are regularly integrated!
Good listening !!!