Monday, April 4, 2011

Project 24 - LCD Temperature Display

I added in the pushbutton and temperature sensor to the circuit I built for Project 23... after powering it up, I do get the readings on the screen for both Celsius and Fahrenheit but the numeric values are obviously incorrect.

I consulted the data sheet for the temp sensor but the calibration instructions are confusing and also they're for the "can" version of the sensor and not this extremely tiny sensor I purchased from Sparkfun... not sure if the sensor is defective but I know it's not 211F in my house.

I'd like to figure out why it's not working but without a way to verify the accuracy of the sensor, I'd rather move on to the next project. I'm going to leave the circuit alone for a day and see if anyone has any suggestions... I may also consult the data sheet again to see if I missed anything.


  1. Hi,
    Whats the Temperature Sensor?

  2. Jim,

    There is an error in the diagram that should never have made it to print. There is a wire missing going from the middle pin of the sensor to analog pin 1.


    1. Mike,
      What a great book..Thank you.
      BTW a LCD without backlite does in fact work but is just not impressive.