Qwiic_SGP40_Py

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SparkFun Qwiic RFID Reader

Python module for the SparkFun Qwiic Air Quality Sensor - SGP40

This python package is a port of the existing SparkFun SGP40 Arduino Library

This package can be used in conjunction with the overall SparkFun qwiic Python Package

New to qwiic? Take a look at the entire SparkFun qwiic ecosystem.

Supported Platforms

The Qwiic SGP40 Python package currently supports the following platforms:

Dependencies

This driver package depends on the qwiic I2C driver: Qwiic_I2C_Py

Documentation

The SparkFun Qwiic Sgp40 module documentation is hosted at ReadTheDocs

Installation

PyPi Installation

This repository is hosted on PyPi as the sparkfun-qwiic-sgp40 package. On systems that support PyPi installation via pip, this library is installed using the following commands

For all users (note: the user must have sudo privileges):

sudo pip install sparkfun-qwiic-sgp40

For the current user:

pip install sparkfun-qwiic-sgp40

To install, make sure the setuptools package is installed on the system.

Direct installation at the command line:

python setup.py install

To build a package for use with pip:

python setup.py sdist

A package file is built and placed in a subdirectory called dist. This package file can be installed using pip.

cd dist
pip install sparkfun-qwiic-sgp40-<version>.tar.gz

Example Use

See the examples directory for more detailed use examples.

from __future__ import print_function
import qwiic_sgp40
import time
import sys

def run_example():

    print("\nSparkFun Qwiic Air Quality Sensor - SGP40, Example 1\n")
    my_sgp40 = qwiic_sgp40.QwiicSGP40()

    if my_sgp40.begin() != 0:
        print("\nThe Qwiic SGP40 isn't connected to the system. Please check your connection", \
            file=sys.stderr)
        return

    print("\nSGP40 ready!")

    while True:

        print("\nVOC Index is: " + str(my_sgp40.get_VOC_index()))

        time.sleep(1)

if __name__ == '__main__':
    try:
        run_example()
    except (KeyboardInterrupt, SystemExit) as exErr:
        print("\nEnding Example 1")
        sys.exit(0)

SparkFun - Start Something

Table of Contents

API Reference

qwiic_sgp40

Python module for the SparkFun Air Quality Sensor - SGP40 (Qwiic).

This package is a port of the existing [SparkFun SGP40 Arduino Library](https://github.com/sparkfun/SparkFun_SGP40_Arduino_Library) and is heavily based on the driver written by [DFRobot](https://github.com/DFRobot/DFRobot_SGP40/tree/master/Python/raspberrypi).

This package can be used in conjunction with the overall [SparkFun Qwiic Python Package](https://github.com/sparkfun/Qwiic_Py)

New to qwiic? Take a look at the entire [SparkFun Qwiic Ecosystem](https://www.sparkfun.com/qwiic).

class qwiic_sgp40.QwiicSGP40(address=None, i2c_driver=None)[source]
Parameters

  • address – The I2C address to use for the device. If not provided, the default address is used.

  • i2c_driver – An existing i2c driver object. If not provided a a driver object is created.

Returns

The GPIO device object.

Return type

Object

begin(warm_up_time=10)[source]

Initialize the operation of the Qwiic SGP40 and wait through warm- up time. Run is_connected() and measure_test().

Returns

Returns true if the intialization was successful, false otherwise.

Return type

bool

get_VOC_index(_QwiicSGP40__relative_humidity=50, _QwiicSGP40__temperature_c=25)[source]

Get VOC index

Parameters

  • __relative_humidity – float relative humidity between 0 and 100%.

  • __temperature_c – float temperature in celcius between -45 and 130 degrees.

Returns

VOC index

Return type

int

heater_off()[source]

Turns the hotplate off and puts sensor in idle mode.

Return type

void - returns nothing

is_connected()[source]

Determine if a Qwiic SGP40 device is connected to the system.

Returns

True if the device is connected, false otherwise.

Return type

bool

measure_raw(_QwiicSGP40__relative_humidity=50, _QwiicSGP40__temperature_c=25)[source]

Returns the raw data. See the SGP40 datasheet for more info.

Parameters

  • SRAW_ticks – variable to assign raw measurement to

  • __relative_humidity – float relative humidity between 0 and 100%.

  • __temperature_c – float temperature in celcius between -45 and 130 degrees.

Returns

0 if CRC checks out, -1 otherwise

Return type

int

measure_test()[source]

Sensor runs chip self test.

Returns

Returns 0 if the self-test succeeded and 1 if it failed.

Return type

int

soft_reset()[source]

Sensor reset

Return type

void - returns nothing

Example One - Get VOC Index

examples/qwiic_sgp40_ex1.py
 1# !/usr/bin/env python
 2# ----------------------------------------------------------------------
 3# qwiic_sgp40_ex1.py
 4#
 5# Simple example to get VOC index
 6# ----------------------------------------------------------------------
 7#
 8# Written by Priyanka Makin @ SparkFun Electronics, June 2021
 9#
10# This python library supports the SparkFun Electronics qwiic sensor/
11# board ecosystem on a Raspberry Pi (and compatable) single board 
12# computers.
13#
14# More information on qwiic is at https://www.sparkfun.com/qwiic
15#
16# Do you like this library? Help support SparkFun by buying a board!
17#
18# ======================================================================
19# Copyright (c) 2021 SparkFun Electronics
20#
21# Permission is hereby granted, free of charge, to any person obtaining 
22# a copy of this software and associated documentation files (the 
23# "Software"), to deal in the Software without restriction, including 
24# without limitation the rights to use, copy, modify, merge, publish, 
25# distribute, sublicense, and/or sell copies of the Software, and to 
26# permit persons to whom the Software is furnished to do so, subject to 
27# the following conditions:
28#
29# The above copyright notice and this permission notice shall be 
30# included in all copies or substantial portions of the Software.
31#
32# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
33# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
34# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
35# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 
36# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
37# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 
38# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
39#=======================================================================
40# Example 1
41
42from __future__ import print_function
43import qwiic_sgp40
44import time
45import sys
46
47def run_example():
48
49	print("\nSparkFun Qwiic Air Quality Sensor - SGP40, Example 1\n")
50	my_sgp40 = qwiic_sgp40.QwiicSGP40()
51	
52	if my_sgp40.begin() != 0:
53		print("\nThe Qwiic SGP40 isn't connected to the system. Please check your connection", \
54			file=sys.stderr)
55		return
56	
57	print("\nSGP40 ready!")
58	
59	while True:
60		
61		print("\nVOC Index is: " + str(my_sgp40.get_VOC_index()))
62		
63		time.sleep(1)
64
65if __name__ == '__main__':
66	try:
67		run_example()
68	except (KeyboardInterrupt, SystemExit) as exErr:
69		print("\nEnding Example 1")
70		sys.exit(0)

Indices and tables