https://github.com/sensirion/raspberry-pi-i2c-sgp41
The SGP41 is Sensirion’s new digital VOC (volatile organic compounds) and NOx sensor designed for easy integration into air purifiers or demand-controlled ventilation.
https://github.com/sensirion/raspberry-pi-i2c-sgp41
driver i2csgp nox raspberry-pi sensirion sensor sgp41 sgp4x voc
Last synced: about 1 month ago
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The SGP41 is Sensirion’s new digital VOC (volatile organic compounds) and NOx sensor designed for easy integration into air purifiers or demand-controlled ventilation.
- Host: GitHub
- URL: https://github.com/sensirion/raspberry-pi-i2c-sgp41
- Owner: Sensirion
- License: bsd-3-clause
- Created: 2021-08-10T16:31:21.000Z (almost 5 years ago)
- Default Branch: master
- Last Pushed: 2024-05-23T18:20:59.000Z (about 2 years ago)
- Last Synced: 2025-06-04T13:29:51.979Z (about 1 year ago)
- Topics: driver, i2csgp, nox, raspberry-pi, sensirion, sensor, sgp41, sgp4x, voc
- Language: C
- Homepage:
- Size: 635 KB
- Stars: 2
- Watchers: 4
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
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README
# Sensirion Raspberry Pi I2C SGP41 Driver
This document explains how to set up the SGP41 sensor to run on a Raspberry Pi
using the provided code.
[
](https://www.sensirion.com/en/environmental-sensors/gas-sensors/sgp41)
Click [here](https://www.sensirion.com/en/environmental-sensors/gas-sensors/sgp41) to learn more about the SGP41 Sensor.
## Setup Guide
### Connecting the Sensor
Your sensor has the four different connectors: VCC, GND, SDA, SCL. Use
the following pins to connect your SGP41:
*SGP41* | *Raspberry Pi*
:------: | :------------------:
VCC | Pin 1 (3.3V)
GND | Pin 6
SDA | Pin 3
SCL | Pin 5
### Raspberry Pi
- [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 driver for the [Sensirion Github Page](https://github.com/Sensirion/raspberry-pi-i2c-sgp41) and extract the `.zip` on your Raspberry Pi
- Compile the driver
1. Open a [terminal](https://www.raspberrypi.org/documentation/usage/terminal/?)
2. Navigate to the driver directory. E.g. `cd ~/raspberry-pi-i2c-sgp41`
3. Run the `make` command to compile the driver
Output:
```
rm -f sgp41_i2c_example_usage
cc -Os -Wall -fstrict-aliasing -Wstrict-aliasing=1 -Wsign-conversion -fPIC -I. -o sgp41_i2c_example_usage sgp41_i2c.h sgp41_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 sgp41_i2c_example_usage.c
```
- Test your connected sensor
- Run `./sgp41_i2c_example_usage` in the same directory you used to
compile the driver.
Output:
```
SRAW VOC: 25720
SRAW NOx: conditioning
SRAW VOC: 25846
SRAW NOx: conditioning
...
SRAW VOC: 25951
SRAW NOx: 15656
SRAW VOC: 26153
SRAW NOx: 15612
SRAW VOC: 26278
SRAW NOx: 15553
...
```
## Conditioning
After each restart of the sensor or when the hotplates have been switched off, the conditioning command must
be called from idle mode. The conditioning heats the hotplate of the NOx pixel to a different temperature compared
to the measurement mode enabling a faster switch-on thereafter.
It is recommended to execute the conditioning for 10s, but **10s must not be exceeded** to avoid damage to the sensing material.
## Troubleshooting
### Initialization failed
- 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 ./sgp41_i2c_example_usage`), it's
typically due to wrong permission settings.