sen5x-go

README

sen5x-go

A wrapper for the Raspberry Pi Driver provided by Sensirion for the SEN5x sensors family that can write the measurements to a csv file and send them to the cloud to sensor.community.

Why Go?

Go is very fast and easily to write language that can be compiled to a single binary unlike Python which needs a lot of dependencies and also needs to be installed on the target system. With Go you can just copy the binary to your Raspberry Pi and run it. No need to install anything else.

Compatibility

Tested with a Raspberry PI Zero 2W but should work with the PI 4 as well.

[!WARNING] Using the 64-bit version of Raspberry PI OS is required to run the precompiled binary.

Installation

The installation is very easy. Just copy the binary to your Raspberry Pi and run it. You can find the latest binary in the Github releases page.

systemd service

To run the binary automatically, even after a power loss, you can easily create a systemd service. Just create a file in /etc/systemd/system/sen5x.service with the following content:

[Unit]
Description=Runs the data collection script for the SEN55, even after a reboot of the system.
After=network.target
Wants=network-online.target

[Service]
WorkingDirectory=/home/aggellos2001
Restart=always
Type=simple
ExecStart=/home/aggellos2001/sen5x-bin
 
[Install]
WantedBy=multi-user.target

After that you need to reload the systemd daemon with the command

sudo systemctl daemon-reload

and enable the service with

sudo systemctl enable sen5x.service

Make sure to start the service also for the first time with

sudo systemctl start sen5x.service

If you run the script as a service and you want to see the logs you can use the command sudo journalctl -u sen5x.service -f to see the logs in real time.

Configuration

This script is higly configurable. It uses the TOML format which you can learn more here.

When you run the script for the first time, it will create a file called config.toml in the same directory as the binary. You can edit this file to change the configuration of the script.

The default config.toml configuration with some comments to help you understand what each option does is included in the repository.

Sensor Community

Here's a short guide on how to get your SensorNodeID from sensor.community.

Firstly, you will need to make an account on https://devices.sensor.community/.

Then, go to My sensors tab and click Register new sensor.

On the Sensor ID field you must put something unique. It's recommended to put the serial number of your Raspberry Pi.

You can find easily your serial number by running:

cat /proc/cpuinfo | grep Serial | cut -d ' ' -f 2

The rest of the options are self expainatory except the hardware configuration. For this script you need to pick a SPS30 and a SHT30 component.

The SPS30 will be used to upload the particulate matter data and the SHT30 will be used to upload the temperature and humidity data.

Currently the NOx and VOC data are not supported by the script to upload to sensor.community.

After you click Save settings you new sensor node will appear on your list of sensors in the My sensors tab.

All you need is to copy the SensorUID and put in the config.toml file in the SensorCommunity section (and of course set the Enabled option to true).

After that you can run the script and it will upload the data to sensor.community.

Updates

Check the releases page for updates of the script. When a new version contains changes to the config.toml file it will automatically update and remove or add default values to the config.toml file as need so make sure to read the release notes and check the config yourself after an update.

Cross compiling for Raspberry Pi

If you want to cross compile the script from the source for the Raspberry Pi you can use the following command:

CGO_ENABLED=1 GOOS=linux GOARCH=arm64 CC=aarch64-linux-gnu-gcc CC_FOR_TARGET=gcc-aarch64-linux-gnu go build -o bin/sen5x-bin .

For this to work you need to have the appriopriate compiler installed and also your system should have a compatible libc version. Currently RaspberryPI OS is based on Debian 11, so you need GGLIBC 2.31 or older.

Versioning

This project uses Go's module version numbering rules.

Contributing

If you want to contribute to this project, feel free to open a pull request. I will be happy to review it. If you have any questions, feel free to open an issue and make sure to follow the appropriate template.

Documentation

Overview

This program uses the SEN55 sensor from Sensirion to take various measurements and print them to a file and or the community site sensor.community if configured. A configuration file is available at the github repository that you may use to configure all the available The folder sen5xlib contains the C bindings and the functions to communicate with the sensor that Sensirion provides at their github repository. This program is not endorsed by Sensirion!