My son and myself made a little arduino robot that records temperature. He wanted me to draw a robot, I wanted to experiment with blinking LEDs relaying data so a plan was hatched. The way the LEDs work is as follows: Green = lowest temperature recorded, Yellow = highest and Red = current temperature with all readings being in °C.

Step 1: The Ingredients

The ingredients are rather simple and comprise of the following:

Arduino
LM35 temperature sensor
3 LEDs (1 x red, 1 x yellow, 1 x green)
9v battery and lead
Small breadboard and the usual wires
Small cardboard box

Step 2: Wiring Up

I realise now how bad the photograph is but as everything is nice and secure in the robot now, it would be difficult to take it out and photograph again - sorry.

The LEDs come off the following pins: Red (for current temperature) D13, Yellow (highest) D12 and Green (lowest) D11.
The thermometer conects to the 5v and Ground and feeds into pin A0.

Step 3: The Code

The code is made up from tutorials etc from the forums. It's a little messy I think but would love it if you pulled it apart and added your own take on the idea. Anyway download from here and upload. Meanwhile get your little monkey to draw or colour in the robot on the face of the small cardboard box. Once completed, make three holes for the LEDs to pop through in the face and a hole on the side for the temperature sensor to look through.

Robot_Temp.txt
Download

Step 4: And Finally

Thank you for getting this far. I love making stuff but this is my first tutorial so I think I'm going to need some practice writing these things.

Here's a little video of me taking it into my cold workshop: http://www.youtube.com/watch?v=361J19hbDgk

Please feel free to comment and suggest ways of improving this little toy of ours. I was thinking maybe adding an additional LED to denote whether a reading is a positive or a cold minus temperature.