DHT Sensor FFI

A Ruby library for reading from a DHT-11 or DHT-22 type sensor connected to a Raspberry Pi

Installation

First install the bcm2835 lib (v1.51+), available at: http://www.airspayce.com/mikem/bcm2835

Then either install manually

gem install dht-sensor-ffi

or add to your Gemfile

gem "dht-sensor-ffi"

Usage

require "dht-sensor-ffi"
val = DhtSensor.read(4, 22) # pin=4, sensor type=DHT-22
puts val.temp               # => 21.899999618530273 (temp in C)
puts val.temp_f             # => 71.4199993133545 (temp in F)
puts val.humidity           # => 22.700000762939453 (relative humidity %)

val = DhtSensor.read(4, 22, 10) # 10 retries

There is also a simple binary for testing purposes

$ dht_sensor
Temperature: 22.40 C Humidity: 26.70%

Note: Running as root may be required, depending on your configuration. YMMV!

Contributing to dht-sensor-ffi

  • Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet.
  • Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it.
  • Fork the project.
  • Start a feature/bugfix branch.
  • Commit and push until you are happy with your contribution.
  • Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
  • Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright (c) 2014 Chetan Sarva. Licensed under the MIT license. See LICENSE.txt for further details.