The Raspberry Pi Zero GPIO is a great interface, but it does lack the analog ports you would find on something like an Arduino. We can use PWM to utilize analog devices over the digital ports, like we did with the first photoresistor recipe, or we can add an analog-to-digital convertor (ADC) to our circuit. As you can probably guess, the ADC will read the voltage and convert it into a digital signal that the Raspberry Pi understands natively. The MCP3008 analog-to-digital convertor will handle up to eight analog signals and report back over the SPI interface. Let's get started!
We will use the MCP3008 ADC. Along with that, you'll need the following:
One photoresistor (the one used in the earlier recipe is fine)
One thermistor
Two 10K resistors
