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    A New Chapter for MagicMirror: The Community Takes the Lead
    Read the statement by Michael Teeuw here.

    AHT20 Humidity + Temperature Sensor

    Scheduled Pinned Locked Moved Solved Requests
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    • R Offline
      rkorell @JohnGalt
      last edited by

      @JohnGalt cool.
      congratulations.
      It’s may be worth to show the community what you have done?

      Regards,
      Ralf

      J 1 Reply Last reply Reply Quote 0
      • J Offline
        JohnGalt @rkorell
        last edited by

        @rkorell Yes, I can describe how I arrived at a resolution for my particular problem - which was to replace DHTxx sensors with the more accurate AHT20 temperature and humidity sensors.

        Caveat: I do not necessarily recommend this for the average person though, because I did not find Magic Mirror modules that natively support this sensor, and as a result had to make changes outside of the config.js and custom.css files. As usual, this puts me at risk of something breaking when the module is updated.

        The module being used (MMM-Temperature - found at https://github.com/Tom-Hirschberger/MMM-Temperature) utilizes python scripts to capture the data from the sensor. While the module is quite complete, with script support for many sensors, I did create a new script in order to use this particular sensor.

        The sensor is supported by Adafruit (https://learn.adafruit.com/adafruit-aht20/python-circuitpython), with instructions to install various adafruit libraries including adafruit-ahtx0 (sudo pip3 install adafruit-circuitpython-ahtx0).

        Using those libraries, your script needs to include the following instructions:

        import board
        import adafruit_ahtx0
        sensor = adafruit_ahtx0.AHTx0(board.I2C())
        

        One of the existing scripts supports I2C sensors using the Adafruit libraries, so it looked like a good candidate to use as a model. See htu21:

        #!/usr/bin/env python3
        #pip3 install adafruit-circuitpython-htu21d
        import board
        from adafruit_htu21d import HTU21D
        import json
        
        result = {}
        try:
            # Create sensor object, communicating over the board's default I2C bus
            i2c = board.I2C()  # uses board.SCL and board.SDA
            sensor = HTU21D(i2c)
            result["temperature_c"] = sensor.temperature
            result["humidity"] = sensor.relative_humidity
            result["temperature_f"] = (result["temperature_c"]*1.8) + 32
            result["error"] = False
        except:
            result["temperature_c"] = 0.0
            result["humidity"] = 0.0
            result["temperature_f"] = (result["temperature_c"]*1.8) + 32
            result["error"] = True
        
        print(json.dumps(result))
        

        My resulting script is aht20:

        #!/usr/bin/env python3
        # aht20: Modeled on htu21 
        # pip3 install adafruit-circuitpython-htu21d
        # pip3 install adafruit-circuitpython-ahtx0
        import board
        import adafruit_ahtx0
        import json
        
        result = {}
        try:
            # Create sensor object, communicating over the board's default I2C bus
            i2c = board.I2C()  # uses board.SCL and board.SDA
            # sensor = HTU21D(i2c)
            sensor = adafruit_ahtx0.AHTx0(board.I2C())
            result["temperature_c"] = sensor.temperature
            result["humidity"] = sensor.relative_humidity
            result["temperature_f"] = (result["temperature_c"]*1.8) + 32
            result["error"] = False
        except:
            result["temperature_c"] = 0.0
            result["humidity"] = 0.0
            result["temperature_f"] = (result["temperature_c"]*1.8) + 32
            result["error"] = True
        
        print(json.dumps(result))
        

        This module is now displaying the temperature and humidity from the sensor directly connected it it. Now all I have to do is figure out the complicated css and get it to look like the other modules on my Magic Mirror.

        Barring any objections, I will mark this as solved.

        S R 2 Replies Last reply Reply Quote 1
        • S Offline
          sdetweil @JohnGalt
          last edited by

          @JohnGalt css, use the developers window

          see the second link in my signature below

          Sam

          How to add modules

          learning how to use browser developers window for css changes

          J 1 Reply Last reply Reply Quote 0
          • R Offline
            rkorell @JohnGalt
            last edited by rkorell

            @JohnGalt Really COOL!
            Thanks for sharing!
            Ralf

            J 1 Reply Last reply Reply Quote 0
            • J Offline
              JohnGalt @sdetweil
              last edited by

              @sdetweil – Thanks for the reminder, I’ll take a look.

              1 Reply Last reply Reply Quote 0
              • J Offline
                JohnGalt @rkorell
                last edited by

                @rkorell – My pleasure.

                1 Reply Last reply Reply Quote 1
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