Introduction¶
A CircuitPython driver for the Sensirion SGP30 gas sensor with eCO2 and TVOC output. This sensor uses I2C!
Dependencies¶
This driver depends on:
Please ensure all dependencies are available on the CircuitPython filesystem. This is easily achieved by downloading the Adafruit library and driver bundle.
Usage Notes¶
See the guide for wiring and installation instructions.
First, import the library:
import busio
import adafruit_sgp30
Next, initialize the I2C bus object:
from board import *
i2c_bus = busio.I2C(board.SCL, board.SDA, frequency=100000)
Since we have the I2C bus object, we can now use it to instantiate the SGP30 object:
sgp30 = adafruit_sgp30.Adafruit_SGP30(i2c_bus)
Reading from the Sensor¶
To read from the sensor:
co2eq, tvoc = sgp30.iaq_measure()
print("CO2eq = %d ppm \t TVOC = %d ppb" % (co2eq, tvoc))
Contributing¶
Contributions are welcome! Please read our Code of Conduct before contributing to help this project stay welcoming.
Building locally¶
To build this library locally you’ll need to install the circuitpython-build-tools package.
python3 -m venv .env
source .env/bin/activate
pip install circuitpython-build-tools
Once installed, make sure you are in the virtual environment:
source .env/bin/activate
Then run the build:
circuitpython-build-bundles --filename_prefix adafruit-circuitpython-sgp30 --library_location .
Sphinx documentation¶
Sphinx is used to build the documentation based on rST files and comments in the code. First, install dependencies (feel free to reuse the virtual environment from above):
python3 -m venv .env
source .env/bin/activate
pip install Sphinx sphinx-rtd-theme
Now, once you have the virtual environment activated:
cd docs
sphinx-build -E -W -b html . _build/html
This will output the documentation to docs/_build/html
. Open the index.html in your browser to
view them. It will also (due to -W) error out on any warning like Travis will. This is a good way to
locally verify it will pass.
Table of Contents¶
Simple test¶
Ensure your device works with this simple test.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | """ Example for using the SGP30 with CircuitPython and the Adafruit library"""
import time
import board
import busio
import adafruit_sgp30
i2c = busio.I2C(board.SCL, board.SDA, frequency=100000)
# Create library object on our I2C port
sgp30 = adafruit_sgp30.Adafruit_SGP30(i2c)
print("SGP30 serial #", [hex(i) for i in sgp30.serial])
sgp30.iaq_init()
sgp30.set_iaq_baseline(0x8973, 0x8aae)
elapsed_sec = 0
while True:
print("co2eq = %d ppm \t tvoc = %d ppb" % (sgp30.co2eq, sgp30.tvoc))
time.sleep(1)
elapsed_sec += 1
if elapsed_sec > 10:
elapsed_sec = 0
print("**** Baseline values: co2eq = 0x%x, tvoc = 0x%x"
% (sgp30.baseline_co2eq, sgp30.baseline_tvoc))
|
adafruit_sgp30
¶
I2C driver for SGP30 Sensirion VoC sensor
- Author(s): ladyada
Implementation Notes¶
Hardware:
- Adafruit SGP30 Air Quality Sensor Breakout - VOC and eCO2 (Product ID: 3709)
Software and Dependencies:
- Adafruit CircuitPython firmware for the ESP8622 and M0-based boards: https://github.com/adafruit/circuitpython/releases
- Adafruit’s Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
-
class
adafruit_sgp30.
Adafruit_SGP30
(i2c, address=88)[source]¶ A driver for the SGP30 gas sensor.
-
baseline_co2eq
¶ Carbon Dioxide Equivalent baseline value
-
baseline_tvoc
¶ Total Volatile Organic Compound baseline value
-
co2eq
¶ Carbon Dioxide Equivalent in parts per million
-
set_iaq_baseline
(co2eq, tvoc)[source]¶ Set the previously recorded IAQ algorithm baseline for CO2eq and TVOC
-
tvoc
¶ Total Volatile Organic Compound in parts per billion.
-