This instructable will show you how to make a thermometer that displays the temperature of the air.
It's not the most accurate thermometer in the world, but for this price and the fact that it was homemade...
Step 1: Parts
You will need:
2x7 segment display
1x1800 ohm resistor
1x KTY-13-5 (temperature sensor)
Step 2: Circuit
I tried to make the circuit as simple as I could without over complicating the program.
Step 3: Software
You can change the resistor you use with the sensor and the formula for calculating the temperature if you got a different sensor.
Step 4: Uses
Now you might wonder where you could use this thermometer.
You can use it in your computer, but you should have plexi glass.
You could also use it for measuring the temperature in a room.
And what about putting it in a greenhouse and monitoring the temperature?
You should just remember that it isn't very accurate.