Datasheet

The sensors

We'll use two basic sensors to log data, a CdS photocell to track light (http://adafru.it/aIH)

(this will tell us when the door has been opened) and a semiconductor temperature sensor

to log the ambient fridge temperature. (http://adafru.it/aIH)

We have two great tutorials for these sensors on our site, if you haven't used them before

or need some refreshment, please read them now (http://adafru.it/c7d)!

We will wire the sensors as shown in the diagram below.

Note that we connect ARef, the power pin of the temp sensor, and the light sensor to 3.3V

not to 5.0V - we do this because the 5V line is very noisy and the 3.3V regulator is better

filtered. In the actual board we used the 3.3V line from the datalogger's regulator, see the

images below - in theory its the same as the one off of the Arduino but we trust ours more.