This chapter introduced several new concepts, including pulse width modulation and using threads in our application. You also learned how to use a photoresistor and read the values from it.

Another important step we performed was modifying our motor shield. This provided an introduction to doctoring off-the-shelf Arduino shields to work with the Raspberry Pi.

Next, we will examine how we can build a damp and water detection system. This will incorporate both the Arduino Uno and the Raspberry Pi.

Using this device, we can know whether high humidity has been detected (which can be a sign of damp), and send an alert to the Raspberry Pi to inform us that we potentially have a problem.