https://github.com/sensirion/raspberry-pi-i2c-sen66
C driver to work with Sensirion's SEN66 environmental sensor modules via I2C
https://github.com/sensirion/raspberry-pi-i2c-sen66
all-in-one co2 driver environmental-monitoring evaluation-kit humidity i2c module nox particulate-matter particulate-matter-sensor raspberry-pi sen66 sen6x sen6x-sek sensirion sensor temperature voc
Last synced: 6 months ago
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C driver to work with Sensirion's SEN66 environmental sensor modules via I2C
- Host: GitHub
- URL: https://github.com/sensirion/raspberry-pi-i2c-sen66
- Owner: Sensirion
- License: bsd-3-clause
- Created: 2024-10-30T08:14:22.000Z (11 months ago)
- Default Branch: main
- Last Pushed: 2025-03-13T12:25:25.000Z (7 months ago)
- Last Synced: 2025-03-13T13:23:18.155Z (7 months ago)
- Topics: all-in-one, co2, driver, environmental-monitoring, evaluation-kit, humidity, i2c, module, nox, particulate-matter, particulate-matter-sensor, raspberry-pi, sen66, sen6x, sen6x-sek, sensirion, sensor, temperature, voc
- Language: C
- Homepage:
- Size: 518 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
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README
# Sensirion Raspberry Pi I²C SEN66 Driver
The repository provides a driver for setting up a SEN66 sensor to run on a Raspberry Pi over I²C.
Click [here](https://sensirion.com/sen6x-air-quality-sensor-platform) to learn more about the Sensirion SEN66 sensor.
The default I²C address of [SEN66](https://www.sensirion.com/products/catalog/SEN66) is **0x6B**.
## Connect the sensor
Your sensor has 4 different connectors: VDD, GND, SDA, SCL.
Use the following pins to connect your SEN66:
| *SEN66* | *Cable Color* | *Raspberry Pi* |
| :----------------: | -------------- | ------------------ |
| VDD | red | Pin 1
| GND | black | Pin 6
| SDA | green | Pin 3
| SCL | yellow | Pin 5
### Detailed sensor pinout
| *Pin* | *Cable Color* | *Name* | *Description* | *Comments* |
|-------|---------------|:------:|----------------|------------|
| 1 | red | VDD | Supply Voltage | 3.3V ±5%
| 2 | black | GND | Ground |
| 3 | green | SDA | I2C: Serial data input / output | TTL 5V compatible
| 4 | yellow | SCL | I2C: Serial clock input | TTL 5V compatible
| 5 | | NC | Do not connect | Ground (Pins 2 and 5 are connected internally)
| 6 | | NC | Do not connect | Supply voltage (Pins 1 and 6 are connected internally)
## Quick start example
- [Install the Raspberry Pi OS on to your Raspberry Pi](https://projects.raspberrypi.org/en/projects/raspberry-pi-setting-up)
- [Enable the I²C interface in the raspi-config](https://www.raspberrypi.org/documentation/configuration/raspi-config.md)
- Download the SEN66 driver from [Github](https://github.com/Sensirion/raspberry-pi-i2c-sen66) and extract the `.zip` on your Raspberry Pi
- Connect the SEN66 sensor as explained in the [section above](#connect-the-sensor)
- Compile the driver
1. Open a [terminal](https://projects.raspberrypi.org/en/projects/raspberry-pi-using/8)
2. Navigate to the driver directory. E.g. `cd ~/raspberry-pi-i2c-sen66`
3. Navigate to the subdirectory example-usage.
4. Run the `make` command to compile the driver
Output:
```
rm -f sen66_i2c_example_usage
cc -Os -Wall -fstrict-aliasing -Wstrict-aliasing=1 -Wsign-conversion -fPIC -I. -o sen66_i2c_example_usage sen66_i2c.h sen66_i2c.c sensirion_i2c_hal.h sensirion_i2c.h sensirion_i2c.c \
sensirion_i2c_hal.c sensirion_config.h sensirion_common.h sensirion_common.c sen66_i2c_example_usage.c
```
- Test your connected sensor
- Run `./sen66_i2c_example_usage` in the same directory you used to
compile the driver. You should see the measurement values in the console.
## Troubleshooting
### Building driver failed
If the execution of `make` in the compilation step 3 fails with something like
```bash
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 `./sen66_i2c_example_usage` but do not get sensor readings but something like this instead
```
Error executing device_reset(): -1
Error executing get_serial_number(): -1
Error executing start_continuous_measurement(): -1
...
```
then go through the below troubleshooting steps.
- Ensure that you connected the sensor correctly: All cables are fully
plugged in and connected to the correct pin.
- Ensure that I²C is enabled on the Raspberry Pi. For this redo the steps on
"Enable the I²C interface in the raspi-config" in the guide above.
- Ensure that your user account has read and write access to the I²C device.
If it only works with user root (`sudo ./sen66_i2c_example_usage`), it's
typically due to wrong permission settings. See the next chapter how to solve this.
### 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!**
This Sensirion library uses
[`clang-format`](https://releases.llvm.org/download.html) 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.
```bash
clang-format -i *.c *.h
```
Note that differences from this formatting will result in a failed build until
they are fixed.
## License
See [LICENSE](LICENSE).