You might not have had to write any functions yet. But you've used plenty of them. This guide explores functions in CircuitPython: why you want them, how to make them, and how to get the most out of them.

Make a descent vehicle for your Circuit Playground Express that JPL would be proud of. OK, maybe not quite that, but it's a cool application of the accelerometer and a couple servos.

Use a CRICKIT robotics board to build a robot that can maneuver around a space by interacting with its environment.

GBoard is an alternate keyboard for Android Devices that lets you type using Morse code. This has seen use for people with limited mobility, but it can also be useful for practicing your morse code skills. The goal of this project is to build a simple input device for GBoard that doesn't require soldering or elaborate construction techniques. We'll be using a Circuit Playground Express to build this project. We have a few different versions we'll be demonstrating - from the simplest using the two onboard buttons, to using capacitive touch inputs, to connecting up some alligator clips to big-and-easy-to-press arcade buttons.

Cricket provides an easy way to add measurement and action to a project. Adafruit IO provides an easy way to collect data from devices, make some basic decisions based on it, and communicate back to devices. Putting them together by using a Feather with network capabilities opens the gates to some interesting possibilities.

CircuitPython (and Python) gives you a lot of tools for storing and manipulating data. Storing that data in ways that makes sense become important when on a small microcontroller board. This guide looks at three data structures that CircuitPython provides.

Pomodoro timer is a technique for keeping focused on your work while also taking regular breaks. This project uses some NeoPixels, a rotary encoder and an ItsyBitsy M0 Express to make one.

When you use the Circuit Playground Express and it's matching Cricket you have access to the accelerometer on the CPX. Not so with the Feather version. This guide will help you add an accelerometer to the FeatherWing Crickit.

Using a TrinketM0, NeoPixels, a distance sensor breakout, and some CircuitPython code, make a small board that will control lighting based on how close something is.

We look at the ATMega328, one of the most prolific 8-bit MCUs. The '328 can be found in the Arduino UNO and various other microcontroller boards. To better understand MCUs, and be able to work with them more effectively, we need to go inside and understand what's in there and how it all works.

Build a simple battery powered temperature and humidity monitor with a audio alert. This project uses the Adafruit Trinket M0 and Si7021 temperature and humidity sensor. A TPL5110 module provides battery management to ensure months of operation on a single battery charge.

Building a retro micro project can be fun, but using old ultraviolet EPROMS is difficult. But, you can build a ROM emulator. In this guide, we'll walk through the design and implementation using a Metro M4, a static RAM chip, and a handful of digital logic chips.

In this guide we'll look at digital memory. We'll look at how it evolved over time and where it might go in the future. We'll mostly focus, though, on the types of memory that we can hack with.

In this part we will explore circuits that change their state over time rather than just responding to inputs in a functional way.

Logic gates are fun, but they get even more interesting when you start putting them together.