Sensirion SCD42-D-R2 Mini CO2 Sensor 400-5000 ppm, I2C, Low Power

The SCD42-D-R2 requires a 3.3V DC supply voltage. Its I2C communication interface also operates at 3.3V logic levels. It is not 5V tolerant; if connecting to a 5V microcontroller, level-shifting circuitry is required for the SDA and SCL lines to prevent damage.

Data is read via the I2C protocol. You will need to install the official Sensirion SCD4x library for Arduino or ESP32. The library provides simple functions to start periodic measurements and read the calibrated CO₂ concentration, temperature, and relative humidity values directly from the sensor's registers.

Yes, its low-power design makes it ideal for battery operation. In its optimized single-shot measurement mode, the average current consumption can be as low as 19 mA. By putting the sensor into sleep mode between readings, you can significantly extend battery life in portable air quality monitors.

The SCD42-D-R2 is factory calibrated and does not require user calibration. It features Sensirion's advanced compensation algorithms and the photoacoustic sensing principle, which provides excellent long-term stability and very low drift, ensuring reliable measurements over the product's lifetime.

Yes. While its optimal accuracy range is between 400 and 5000 ppm, the sensor's full specified measurement range extends from 0 up to 40,000 ppm. It is suitable for applications requiring detection of higher concentrations, though accuracy follows a different specification outside the core range.