lib/lib_i2c/arduino-i2c-scd4x/README.md
This is the Sensirion SCD4X library for Arduino allowing you to communicate with a sensor of the SCD4X family over I²C.
Click here to learn more about the Sensirion SCD4X sensor family.
Not all sensors of this driver family support all measurements. In case a measurement is not supported by all sensors, the products that support it are listed in the API description.
| Sensor name | I²C Addresses |
|---|---|
| SCD40 | 0x62 |
| SCD41 | 0x62 |
| SCD43 | 0x62 |
The following instructions and examples use a SCD41.
This library can be installed using the Arduino Library manager: Start the Arduino IDE and open the Library Manager via
Sketch ➔ Include Library ➔ Manage Libraries...
Search for the Sensirion I2C SCD4X library in the Filter your search... field and install it by clicking the install button.
If you cannot find it in the library manager, download the latest release as .zip file and add it to your Arduino IDE via
Sketch ➔ Include Library ➔ Add .ZIP Library...
Don't forget to install the dependencies listed below the same way via library
manager or Add .ZIP Library
Use the following pin description to connect your SCD4X to the standard I²C bus of your Arduino board:
| Pin | Cable Color | Name | Description | Comments |
|---|---|---|---|---|
| 1 | yellow | SCL | I2C: Serial clock input | |
| 2 | black | GND | Ground | |
| 3 | red | VDD | Supply Voltage | 2.4V to 5.5V |
| 4 | green | SDA | I2C: Serial data input / output |
The recommended voltage is 3.3V.
You will find pinout schematics for recommended board models below:
<details><summary>Arduino Uno</summary> <p>| SCD4X | SCD4X Pin | Cable Color | Board Pin |
|---|---|---|---|
| SCL | 1 | yellow | D19/SCL |
| GND | 2 | black | GND |
| VDD | 3 | red | 3.3V |
| SDA | 4 | green | D18/SDA |
| SCD4X | SCD4X Pin | Cable Color | Board Pin |
|---|---|---|---|
| SCL | 1 | yellow | A5 |
| GND | 2 | black | GND |
| VDD | 3 | red | 3.3V |
| SDA | 4 | green | A4 |
| SCD4X | SCD4X Pin | Cable Color | Board Pin |
|---|---|---|---|
| SCL | 1 | yellow | ~D3/SCL |
| GND | 2 | black | GND |
| VDD | 3 | red | 3.3V |
| SDA | 4 | green | D2/SDA |
| SCD4X | SCD4X Pin | Cable Color | Board Pin |
|---|---|---|---|
| SCL | 1 | yellow | D21/SCL |
| GND | 2 | black | GND |
| VDD | 3 | red | 3.3V |
| SDA | 4 | green | D20/SDA |
| SCD4X | SCD4X Pin | Cable Color | Board Pin |
|---|---|---|---|
| SCL | 1 | yellow | GPIO 22 |
| GND | 2 | black | GND |
| VDD | 3 | red | 3V3 |
| SDA | 4 | green | GPIO 21 |
Install the libraries and dependencies according to Installation of the library
Connect the SCD4X sensor to your Arduino as explained in Connect the sensor
Open the exampleUsage sample project within the Arduino IDE:
File ➔ Examples ➔ Sensirion I2C SCD4X ➔ exampleUsage
The provided example is working with a SCD41, I²C address 0x62.
In order to use the code with another product or I²C address you need to change it in the code of examples/exampleUsage.
You find the list with pre-defined addresses in src/SensirionI2CSCD4X.h.
Click the Upload button in the Arduino IDE or Sketch ➔ Upload
When the upload process has finished, open the Serial Monitor or Serial Plotter via the Tools menu to observe the measurement values. Note that
the Baud Rate in the used tool has to be set to 115200 baud.
Contributions are welcome!
This Sensirion library uses
clang-format to standardize the
formatting of all our .cpp and .h files. Make sure your contributions are
formatted accordingly:
The -i flag will apply the format changes to the files listed.
clang-format -i src/*.cpp src/*.h
Note that differences from this formatting will result in a failed build until they are fixed. :
See LICENSE.