Temperature Measuring

LEVEL: Beginner

SKILLS REQUIRED: Breadboard wiring, Spin Programming


This project incorporates the LM34 Temperature sensor with an MCP3202 12-bit ADC and a Propeller Project board to make an accurate, low cost, simple thermometer.  The LM34 is a temperature sensor rated to be accurate to within 1 degree, for operation between +32 to +212 degrees Fahrenheit.  The LM34 outputs an analog voltage that corresponds to the current temperature of its environment.

In this application we are reading the current temperature and displaying it in the Parallax Serial Terminal.  You can modify the program to display the data on an LCD, transmit it over an XBee network from a remote location to your house, or wherever you may need to display the data. 

There have been numerous times when I have needed to add temperature monitoring, or to have temperature-based events triggered.  If you are wanting to prevent pipes from freezing during the winter, you can have heating elements triggered when the temperature reaches 32 degrees Fahrenheit.  If you need to keep a chicken coop cool during the summer, you could trigger a cooling system to turn on when the temperature in the coop gets to some maximum threshold value.  With this simple circuit you will be able to have accurate temperature monitoring incorporated into your project, without spending a lot of time or money.


What's Needed:

  • (1) Propeller Project Board (#32810)
  • (1) MCP3202 12-bit ADC (#604-00060)
  • (1) LM34 Temperature Sensor (#604-00011)
  • (1) 220 ohm resistor (#150-02210)
  • Misc jumper wires