CircuitPython support for DHT11 and DHT22 type temperature/humidity devices
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kattni Merge pull request #20 from ladyada/master
change dht context to static var for linux
Latest commit 507f643 Dec 2, 2018

README.rst

Introduction

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CircuitPython support for the DHT11 and DHT22 temperature and humidity devices.

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 Example

Hardware Set-up

The DHT11 and DHT22 devices both need a pull-resistor on the data signal wire. This resistor is in the range of 1k to 5k. Please check your device datasheet for the appropriate value.

Basics

Of course, you must import the library to use it:

import adafruit_dht

The DHT type devices use single data wire, so import the board pin

from board import <pin>

Now, to initialize the DHT11 device:

dht_device = adafruit_dht.DHT11(<pin>)

OR initialize the DHT22 device:

dht_device = adafruit_dht.DHT22(<pin>)

Read temperature and humidity

Now get the temperature and humidity values

temperature = dht_device.temperature
humidity = dht_device.humidity

These properties may raise an exception if a problem occurs. You should use try/raise logic and catch RuntimeError and then retry getting the values after 1/2 second.

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-veml6070 --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.