Si4703 FM radio receiver breakout with ESP32

Supply 3.3 V Bus I2C I2C address 0x10

Pins and ESP32 wiring

Pin	Role	ESP32 pin	Notes
GND	Ground	GND
3.3V	Power	3V3	3.3 V only
SDIO	I2C data (SDA)	D21	I2C data. Must be LOW when RST goes HIGH to choose I2C mode
SCLK	I2C clock (SCL)	D22
SEN	Not wired to the ESP32	—	Tie HIGH for I2C mode
RST	Input (the ESP32 drives it)	D25	Reset, active LOW. Needed to start I2C mode
GPIO1	Not wired to the ESP32	—	Optional
GPIO2	Interrupt	D35	Seek/tune complete interrupt, optional

Suggested wiring for the 30-pin ESP32 DevKit, avoiding flash, input-only and strapping pins. BoardPilot checks it for you as you wire.

Starter code (Arduino)

#include <Wire.h>

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22);  // SDA = GPIO 21, SCL = GPIO 22
  Wire.beginTransmission(0x10);
  bool found = Wire.endTransmission() == 0;
  Serial.println(found ? "Si4703 FM radio receiver breakout found at 0x10" : "Not found: check power, GND and SDA/SCL");
}

void loop() {}

Sources

Silicon Labs Si4702/03-C19 datasheet, Bus mode selection with RST, SEN and SDIO; 2-wire address 0010000 (0x10)
Silicon Labs AN230 Si4700/01/02/03 programming guide, 2-wire reads start at register 0x0A
SparkFun Si4703 FM tuner breakout, Header order differs between boards: check the silkscreen

Try it in 3D in BoardPilot

BoardPilot Part data (JSON)

Part data: CC BY 4.0, free to reuse with credit to BoardPilot.

Si4703 FM radio receiver breakout with ESP32

Pins and ESP32 wiring

Starter code (Arduino)

Sources

Try it in 3D in BoardPilot

Related parts