Sensirion SCD30 CO2 sensor with ESP32

Supply 3.3-5 V Bus I2C I2C address 0x61 Measures co2, temperature, humidity

Pins and ESP32 wiring

Pin	Role	ESP32 pin	Notes
VDD	Power	3V3	Pin 1
GND	Ground	GND	Pin 2
SCL	I2C clock (SCL)	D22	Pin 3 (TX/SCL). The sensor stretches the clock: use 50 kHz or less
SDA	I2C data (SDA)	D21	Pin 4 (RX/SDA)
RDY	Interrupt	D35	Pin 5. HIGH when a new reading is ready, optional
PWM	Output (the part drives it)	D25	Pin 6. PWM CO2 output, optional
SEL	Not wired to the ESP32	—	Pin 7. Leave open or LOW for I2C; HIGH selects Modbus

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(0x61);
  bool found = Wire.endTransmission() == 0;
  Serial.println(found ? "Sensirion SCD30 CO2 sensor found at 0x61" : "Not found: check power, GND and SDA/SCL");
}

void loop() {}

Sources

Sensirion SCD30 datasheet, Pin 1 VDD, 2 GND, 3 TX/SCL, 4 RX/SDA, 5 RDY, 6 PWM, 7 SEL; supply 3.3 to 5.5 V
Sensirion SCD30 interface description, I2C address 0x61, max 100 kHz, clock stretching up to 150 ms

Try it in 3D in BoardPilot

BoardPilot Part data (JSON)

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

Sensirion SCD30 CO2 sensor with ESP32

Pins and ESP32 wiring

Starter code (Arduino)

Sources

Try it in 3D in BoardPilot

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