Home

Awesome

Sensirion Raspberry Pi I2C SCD30 Driver

This document explains how to set up a SCD30 sensor to run on a Raspberry Pi using the provided code.

<center><img src="images/sensor_scd30_image.jpg" width="300px"></center>

Click here to learn more about the Sensirion SCD30 sensor.

The default I²C address of SCD30 is 0x61.

Setup Guide

Connecting the Sensor

Your sensor has the 5 different connectors: VDD, GND, SCL, SDA, SEL. Use the following pins to connect your SCD30:

SCD30Cable ColorRaspberry Pi
VDDredPin 1
GNDblackPin 6
SCLyellowPin 5
SDAgreenPin 3
SELbluePin 9
<img src="images/raspi-i2c-pinout-3.3V-SEL.png" width="400px">

Detaild sensor pinout

<img src="images/scd30_pinout.jpg" width="300px">
PinCable ColorNameDescriptionComments
1redVDDSupply Voltage3.3 to 5.5V
2blackGNDGround
3yellowSCLI2C: Serial clock input
4greenSDAI2C: Serial data input / output
5RDYHigh when data is availabledo not connect
6PWMdo not connect
7blueSELInterface selectPull to ground or floating for I2C

Raspberry Pi

Troubleshooting

Building driver failed

If the execution of make in the compilation step 3 fails with something like

 make: command not found

your RaspberryPi likely does not have the build tools installed. Proceed as follows:

$ sudo apt-get update
$ sudo apt-get upgrade
$ sudo apt-get install build-essential

Initialization failed

If you run ./scd30_i2c_example_usage but do not get sensor readings but something like this instead

Error executing soft_reset(): -1
Error executing read_firmware_version(): -1
Error executing start_periodic_measurement(): -1
...

then go through the below troubleshooting steps.

Missing I²C permissions

If your user is missing access to the I²C interface you should first verfiy the user belongs to the i2c group.

$ groups
users input some other groups etc

If i2c is missing in the list add the user and restart the Raspberry Pi.

$ sudo adduser your-user i2c
Adding user `your-user' to group `i2c' ...
Adding user your-user to group i2c
Done.
$ sudo reboot

If that did not help you can make globally accessible hardware interfaces with a udev rule. Only do this if everything else failed and you are reasoably confident you are the only one having access to your Pi.

Go into the /etc/udev/rules.d folder and add a new file named local.rules.

$ cd /etc/udev/rules.d/
$ sudo touch local.rules

Then add a single line ACTION=="add", KERNEL=="i2c-[0-1]*", MODE="0666" to the file with your favorite editor.

$ sudo vi local.rules

Contributing

Contributions are welcome!

We develop and test this driver using our company internal tools (version control, continuous integration, code review etc.) and automatically synchronize the master branch with GitHub. But this doesn't mean that we don't respond to issues or don't accept pull requests on GitHub. In fact, you're very welcome to open issues or create pull requests :)

This Sensirion library uses clang-format to standardize the formatting of all our .c 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 *.c *.h

Note that differences from this formatting will result in a failed build until they are fixed.

License

See LICENSE.