Section outline

    • Temperature and Humidity with an AHT20 Sensor

      Review:

      Microcontrollers M _________and C_________

      You have measured:

      • switch condition (on/off) 
      • voltage (potentiometer)
      • distance
      • time (with software)
      • temperature
      • humidity

      You have controlled:

      • LED (on/off)
      • LED brightness (PWM)
      • speaker (frequency, duration)
      • LED strip (color and brightness)

      types of resistor circuits:
      Current Limiting, Pull Down, Voltage Divider (Potentiometer), Pull Up

      Fun Fact:

      Relative Humidity (%) is a measure of how close air is to being saturated with water vapor.
      Cold air can hold less water vapor than warm air
      so... as temp increases Rh(%) decreases - if water content stays the same
      as temp decreases Rh(%) increases - if water content stays the same

      Temp and Humidity Grapgh


      New Parts : AHT20 Temp & Humidity Sensor (4 Leads

      LED Cup Holder

      Demo AHT20 - Link


      Breadboard Circuit:


      LCD Circuit: 

      AHT20 Pin --- Arduino Pin

              Vin         ---     5v

             Gnd        ---     Gnd

             SCL        ---     A5    (SCL)

             SCA        ---     A4   (SCA)



      Program to test the AHT20 writing data to the serial monitor:

      Click Here for Test Program


      Load this Analog Read Code to see how buttons on LCD are encoded to A0:

      Click Here for Analog Read of A0


      Load this program to exercise the LCD with Buttons:

      Click Here for LCD Button Read

      Assignment:

      Create a sketch that:

      Reads Temp and Humidity(%) and prints the Temp (F) and Humidity (%)

      When the "Up" Button is pressed the Temp (C) is displayed for 2 seconds instead of Temp (F)

      When the "Down" Button is pressed the Temp (K) is displayed for 2 seconds instead of Temp (F)

      When the "Left" Button is pressed the LCD displays a NICE message to Mr. Suvar


      Notes:  F = 9/5 C + 32
                    K = C+273


      Temp variables should be floating point (not integer)