LuckyResistor / ReadSGP30

A simple command line tool to read values from an SGP30 sensor attached to a Raspberry Pi.

ReadSGP30

A simple command line tool for Raspberry-Pi to read the values from an SGP30 sensor over the I2C bus.

Basic Usage

There are a number of arguments you can use:

$ read_sgp30 -h
Usage: read_sgp30 [arguments]
 -h --help    Display this help.
 -v --version Display the application version.
 -r           Read the measurements (default).
 -i           Initialize the measurements.
 -t           Perform a measurement test.
 -s           Read serial number.
 -z           Reset the sensor (and other sensors on the same bus!).
 -xs          Store the iAQ baseline.
 -xr          Restore the iAQ baseline.
 -b0 -b1      Select the bus. 1 is the default.
 -d           Show debugging messages.

If you call the command, you will get JSON output:

$ read_sgp30
{ "co2_ppm": 5392, "tvoc_ppb": 48772 }

The idea is to call this command from your script and parse the returned JSON output.

Important Notes

The following important notes are taken from the datasheet. Please read the sensor datasheet for details.

• You need to initialize the sensor once (using -i) after each reset or power cycle before you can do measurements.
• Call -xs every hour to store the baseline value in a file. After a power-loss or reset, restore this baseline with -xr. This will speedup the baseline calculation, which can otherwise take up to 48h.
• The soft reset function uses a general call address, which may also reset other sensors on the same bus.

How to Compile and Install the Tool

In order to compile and install the tool on your Raspberry-Pi, you need to install the compiler, CMake and the I2C-Tools first:

sudo apt install gcc cmake i2c-tools

Download the files of this git repository to a sub directory in your home directory. In this example, I downloaded the files to the directory /home/pi/read_sgp30.

Now create a separate build directory. In this example, I create the directory /home/pi/build_read_sgp30.

Next switch to the build directory, execute cmake to create the build script. Build the executable with make and install the executable in your system with sudo make install.

cd build_read_sht31
cmake ../read_sht31
make
sudo make install

License (GPL v3)

Copyright (c) 2020 by Lucky Resistor.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.