Adafruit SCD-40 True CO2, Temperature & Humidity Sensor
Pinout
- VINheader / STEMMA QT
Main power input
Type · PowerVoltage · 3-5V DC - 3Voheader
3.3V output from onboard regulator
Type · PowerVoltage · 3.3V output - GNDheader / STEMMA QT
Common ground
Type · GroundVoltage · 0V - SCLheader / STEMMA QT
I2C clock with pullup
Type · I2CVoltage · 3-5V logic - SDAheader / STEMMA QT
I2C data with pullup
Type · I2CVoltage · 3-5V logic
| Pin | Position | Type | Function | Voltage |
|---|---|---|---|---|
| VIN | header / STEMMA QT | Power | Main power input | 3-5V DC |
| 3Vo | header | Power | 3.3V output from onboard regulator | 3.3V output |
| GND | header / STEMMA QT | Ground | Common ground | 0V |
| SCL | header / STEMMA QT | I2C | I2C clock with pullup | 3-5V logic |
| SDA | header / STEMMA QT | I2C | I2C data with pullup | 3-5V logic |
Pin details
5 connections- VINheader / STEMMA QT
Main power input
PowerVoltage · 3-5V DC - 3Voheader
3.3V output from onboard regulator
PowerVoltage · 3.3V output - GNDheader / STEMMA QT
Common ground
GroundVoltage · 0V - SCLheader / STEMMA QT
I2C clock with pullup
I2CVoltage · 3-5V logic - SDAheader / STEMMA QT
I2C data with pullup
I2CVoltage · 3-5V logic
Start wiring
I2C · Analog · UART · 3.3 – 5 V · Breakout
Waveshare lists MQ-2 for combustible gases and smoke, MQ-3 for alcohol, and MQ-135 for mixed indoor pollutants such as NH3, NOx, alcohol,…
Module pins: VIN, 3Vo, GND, SCL, SDA. Schematik maps them to your board in the app.
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