Quelltext der Seite WSAL20168 – SGP40 VOC Sensor/en

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'''Documentation notice:''' This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

== Summary ==
The SGP40 VOC sensor is a digital sensing module for air quality monitoring that incorporates the SGP40 chip from Sensirion. It measures volatile organic compounds (VOCs) in the range of 0 to 1000 ppm ethanol equivalents and provides digital signals via an I2C bus for controlling air treatment devices.

== Related products at JW Tech ==
* [https://shop.jw-tech.eu/p/WSAL20168 WSAL20168 – Digital SGP40 VOC (Volatile Organic Compounds) Gas Sensor, I2C Bus]

== Technical overview ==
* Measurement range: 0–1000 ppm ethanol equivalents
* Communication: I2C with fixed address 0x59
* Operating voltage: 3.3 V or 5 V thanks to onboard voltage translator
* Response time: under 10 s (tau 63%)
* Switch-on time: under 60 s
* Dimensions: 27 x 20 mm; mounting hole 2.0 mm
* Pinout: VCC, GND, SDA, SCL
* Use cases: detection of smoke, gas emissions, emissions from construction materials, furniture, and home appliances

'''Commands and examples – verify before use:''' 
<syntaxhighlight lang="text">
sudo raspi-config
sudo reboot
wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.60.tar.gz
tar zxvf bcm2835-1.60.tar.gz
cd bcm2835-1.60/
sudo ./configure
sudo make
sudo make check
sudo make install
sudo apt-get install wiringpi
cd /tmp
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb
gpio -v
sudo apt-get install p7zip-full
wget https://files.waveshare.com/upload/6/62/SGP40_Voc_Sensor_code.7z
7z x SGP40_Voc_Sensor_code.7z -r -o./SGP40_Voc_Sensor_code
sudo chmod 777 -R SGP40_Voc_Sensor_code
cd SGP40_Voc_Sensor_code/RPI/c
sudo make clean
</syntaxhighlight>

== Notes and version constraints ==
* Exact commands and library versions are version-sensitive; verify compatibility with your system before running them.
* The module requires a warm-up phase after power-on; during this time the raw value slowly rises until it stabilizes.
* The sensor is extremely sensitive to ethanol; under normal conditions the VOC reading is near zero unless strong contaminants are present.
* If serial output stops or shows zero after startup: check hardware connections, ensuring SDA and SCL are not swapped; reconnect the sensor and rerun the program.
* Raw data values cannot be directly converted to PPM or PPB; the Sensirion library is required for conversion.

== Source and revision record ==
* [https://www.waveshare.com/wiki/SGP40_VOC_Sensor SGP40 VOC Sensor - Waveshare Wiki]
* Source revision: 69092
* Captured: 2026-09-02T03:28:20+00:00
* SHA-256: <code>3d8869d67a4ffa0d1e134c55c453c0554c5bdbae0321cabbaa3a82f82f43c7e8</code>