Rpi::Dht

gem "rpi-dht"

require "rpi/dht"

pin = 4 # bcm number https://i.gyazo.com/8de74c9e6a7139e30c2f540715a24dc9.png

####################
# GPIO numbering
####################
# RPi::Dht.set_numbering(:bcm)        [default]
# or RPi::Dht.set_numbering(:board)

# Because it can't receive valid data from sensor reliably, there are methods try to read continusly until it gets valid data
# [read_11 and read_22] (without !) are recommended

####################
# for DHT11 sensor
####################
RPi::Dht.read_11!(pin) # raises exception, if you want to manage by yourself
# => returns e.g. {humidity: 12, temperature: 34, temperature_f: 93.2}
# or exception

RPi::Dht.read_11(pin, tries: 50) # tries 50 times and doesn't raise
# or RPi::Dht.read_11(pin) defaults to 50 tries
# => returns e.g. {humidity: 12, temperature: 34, temperature_f: 93.2}
# or nil if it doesn't get valid data

####################
# for DHT22 sensor
####################
RPi::Dht.read_22!(pin) # raises exception, if you want to manage by yourself
# => returns e.g. {humidity: 12.3, temperature: 34.5, temperature_f: 94.1}
# or exception

RPi::Dht.read_22(pin, tries: 50) # tries 50 times and doesn't raise
# or RPi::Dht.read_22(pin) defaults to 50 tries
# => returns e.g. {humidity: 12.3, temperature: 34.5, temperature_f: 94.1}
# or nil if it doesn't get valid data

# read.rb
require "benchmark"
require "rpi/dht"
PIN = 4

Benchmark.bm 10 do |r|
  r.report "reading 10 times" do
    10.times { RPi::Dht.read_22(PIN) }
  end
end

require "pathname"

def read_humidity
  Pathname("/sys/bus/iio/devices/iio\:device0/in_humidityrelative_input").read.to_f / 1000
rescue => ex
  sleep 0.5
  retry
end

def read_temperature
  Pathname("/sys/bus/iio/devices/iio\:device0/in_temp_input").read.to_f / 1000
rescue => ex
  sleep 0.5
  retry
end