{"title":"SparkFun CO₂ Humidity and Temperature Sensor - SCD40 (Qwiic)","handle":"sparkfun-co-humidity-and-temperature-sensor-scd40-qwiic","url":"/products/sparkfun-co-humidity-and-temperature-sensor-scd40-qwiic","description":"The SparkFun SCD40 breakout board measures CO₂ concentration, humidity, and temperature using Sensirion's PASens photoacoustic measurement technology. The sensor detects CO₂ from 0 to 40,000 ppm with high accuracy over the 400–2,000 ppm range, and includes an integrated CMOSens temperature and humidity sensor for improved readings.\n\nThe board connects via I2C through two Qwiic connectors or a standard 2.54 mm (0.1″) header. An automatic self-calibration routine adjusts accuracy over a seven-day period — Sensirion recommends at least one hour of fresh-air readings per day during calibration. The sensor also accepts ambient pressure input for additional accuracy compensation.\n\nKey Features\n\n\nSensirion SCD40 – Photoacoustic CO₂ sensor with integrated temperature and humidity\n\nCO₂ Range – 0–40,000 ppm\n\nCO₂ Accuracy – ±(50 ppm + 5% of reading) over 400–2,000 ppm\n\nHumidity – 0–100% RH, ±9% RH accuracy\n\nTemperature – −10 to +60°C, ±1.5°C accuracy\n\nI2C Interface – Address 0x62, dual Qwiic connectors + breakout header\n\n2.4–5.5V Supply – 3.3V typical\n\nLow Power Modes – Normal: 18 mA typical, low power: 3.5 mA, single-shot: 0.5 mA\n\nAuto Self-Calibration – Seven-day calibration routine for optimal accuracy\n\n\nIdeal For\n\nIndoor air quality monitoring\nHVAC and ventilation control systems\nEnvironmental sensing projects\nSmart building and classroom CO₂ tracking\n\n\nResources\n\nHookup Guide\nSCD4x Datasheet (PDF)\nSchematic (PDF)\nBoard Dimensions\nArduino Library (GitHub)\nHardware Repository (GitHub)\n","vendor":"SparkFun","product_type":"physical","in_stock":true,"options":[],"variants":[{"id":1541,"title":"Default Title","sku":"SF-SEN-22395","price":202.11,"on_sale":false,"in_stock":true,"available_quantity":113,"option1":"Default Title"}]}