IoThings Sound System

ToDo list

HW

• Find a suitable DAC
• Find a suitable amplifier
• Connect a Rotary Encoder with Push-Button
• Rotary potentiometer (generic)

SW

• JSON configuration (last volume, station, source)
• SI4703
• TEA5767

Functionnal

• Connect the Antenna button
• Connect the Volume button
• Connect the High frequencies
• Connect the Low frequencies
• Connect the switches (On/Off, PU, GO, PO, OC, MF)

Resources

Radio Arduino Library

• SI4703 https://docs.rs/si4703/latest/si4703/ https://blog.eldruin.com/si4703-fm-radio-receiver-driver-in-rust/ https://github.com/eldruin/driver-examples/blob/master/stm32f1-bluepill/examples/si4703-fm-radio-bp.rs https://github.com/mkhuthir/Si4703 https://github.com/csdexter/Si4703/tree/master https://github.com/pu2clr/SI470X https://github.com/mathertel/Radio/blob/master/src/SI4703.cpp https://forum.arduino.cc/t/si4703-fm-tuner-question/1172302/3

Notes

DevKitC6: UART left (SLABtoUART) CopyS3: USB Left or COM right (WCH USB Serial ?)

esp-idf-tea5767

TEA5767 FM Stereo Radio Driver for esp-idf.

I ported from here.

Software requirements

ESP-IDF V4.4/V5.x.
ESP-IDF V5.0 is required when using ESP32-C2.
ESP-IDF V5.1 is required when using ESP32-C6.

Hardware requirements

TEA5767 FM Stereo Radio Module.
I bought this on AliExpress about $4.

The module has a standard antenna, but if you want to use it in a room, you need a long antenna.
With a long antenna, you can get more signals.
I used an AC power cable as extended antena.

Installation

git clone https://github.com/nopnop2002/esp-idf-tea5767
cd esp-idf-tea5767
idf.py set-target {esp32/esp32s2/esp32s3/esp32c2/esp32c3/esp32c6}
idf.py menuconfig
idf.py flash

Configuration

• CONFIG_SCL_GPIO
  GPIO number(IOxx) to SCL.
• CONFIG_SDA_GPIO
  GPIO number(IOxx) to SDA.
• CONFIG_FM_BAND
  In US/EU it ranges from 87.5 MHz to 108 MHz.
  In Japan it ranges from 76 MHz to 91 MHz.
  Used when wrapping in a search.

Wiring

TEA5767		ESP32	ESP32-S2/S3	ESP32-C2/C3/C6
SCL	--	GPIO22	GPIO4	GPIO6	(*1)
SDA	--	GPIO21	GPIO3	GPIO5	(*1)
GND	--	GND	GND	GND
VCC	--	3.3V	3.3V	3.3V	(*2)

(*1)
You can change it to any pin using menuconfig.
But it may not work with other GPIOs.

(*2)
The PCB marking is +5V, but it works at 3.3V.

API

Refer to tea5767.h.

How to use

• Search radio station
  Press the + key to search for radio stations upwards.
  Press the - key to search for radio stations downwards.

• Preset radio station
  Press the * key to record the current radio station in NVS.
  At boot time, it read from NVS and set to the current Radio station.

• Change frequence
  Press the D key to decrease the frequence by -1.0Mhz.
  Press the U key to increase the frequence by +1.0Mhz.
  Press the d key to decrease the frequence by -0.1Mhz.
  Press the u key to increase the frequence by +0.1Mhz.

• Clear preset
  idf.py erase-flash

Reference

https://github.com/nopnop2002/esp-idf-fm-radio