When it comes to the hardware, there are a lot of existing guides out there as far as wiring up sensors to a Raspberry Pi. Because of that, and because the wiring can be done perfectly well in many different ways, I'll keep this as more of an overview.

Basic Wiring

With most of the sensors, there will be 3 types of connections that are important, and each of these generally have labeling on the hardware:

• "+" or "VCC", this is normally the positive connection which is wired to a 3.3V or 5V power on the Pi

• "SIG" or "Signal", this is normally the digital signal connection which is wired to a GPIO pin

• "-" or "GND", this is normally the negative connection which is wired to a ground on the Pi

Troubleshooting

I'm noticing, (maybe?) mainly because these electronics are so inexpensive and cheap to produce, that the same model of sensor will often look slightly different and act slightly different depending on where it was produced.

• One example is the PCF8591 D/A Converter which is used with the photoresistor. On one of these, I had to wire the Signal from the photoresistor to AINO and it worked. On the other I had to use AIN3 or it would throw a vague error.