Class: RPi::Dht::Dht22

Inherits:
Base
  • Object
show all
Defined in:
lib/rpi/dht/dht22.rb

Constant Summary

Constants inherited from Base

Base::BITS_IN_BYTE, Base::CLEAR_SIGNALS, Base::ENOUGH_TO_CAPTURE_COUNT, Base::HUMIDITY_PRECISION, Base::START_SIGNAL, Base::TEMPERATURE_PRECISION, Base::VALID_BYTE_SIZE

Instance Method Summary collapse

Methods inherited from Base

#collect_response_bits, #initialize, read, read!, #send_start_signal

Constructor Details

This class inherits a constructor from RPi::Dht::Base

Instance Method Details

#convert ⇒ Object 



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# File 'lib/rpi/dht/dht22.rb', line 4

def convert
  humidity_high, humidity_low, temp_high, temp_low, _ = bytes

  is_negative = 0 < (temp_high & 0b10000000)
  temp_high &= 0b01111111

  humidity = ((humidity_high << 8) + humidity_low) / HUMIDITY_PRECISION
  temperature = ((temp_high << 8) + temp_low) / TEMPERATURE_PRECISION
  temperature *= -1 if is_negative

  {
    humidity: humidity,
    temperature: temperature,
    temperature_f: fahrenheit(temperature)
  }
end