In this chapter, we are going to get the Pico to start observing and interacting with the world around us using basic inputs and outputs, or basic I/O. When we say basic I/O, we mean that we are going to be inputting and outputting digital and analog signals with the GPIO pins of the Pico.

Starting off, digital signals can only be two possible states, either on or off, and when we use the pins of our Pico to output a digital signal, it's kind of like a regular light switch, you can either turn power on or off, no in between. An analog signal, on the other hand, is a signal that can be any value between on and off, or the maximum and minimum values. It's a bit different to a digital output in that it can take any of the values between them.

When we use the pins of our Pico to output an analog signal, we use them kind of like a dimmable light switch, you can set any brightness between fully on and fully off. We're just introducing these concepts now, and once we dive into them with some examples, all of this will become much clearer.

On top of writing code to use the Pico's pins for basic I/O, we're going to just weave in a little bit of circuit making, a little bit of theory on power, and some general knowledge on the Pico, so that by the end of this chapter, you should have the skills to plug in some basic hardware and get your Pico to start interacting with the world around it.