Whether you’re an electronics hobbyist or a full-blown computer science professional, you’re probably familiar with microcontrollers like the Arduino and Raspberry Pi. These pint-sized computing devices make programming and DIY technology projects accessible, approachable, and – best of all – affordable for nearly everyone who is interested.

That begs a few more questions: what does affordable or approachable mean for a hobbyist or someone in an educational environment? And what kinds of projects are well-suited to the diverse audience that might be interested in these devices?

Different use cases can give an idea of what you can accomplish, whether you work for MIT or have never built a tech project in your life. All the examples below propose a project, explain its appeal, and do not exceed a budget of $150.

1. Robot Arm: Project for an Engineering or Computer Science Teacher

The project in brief: pick up a robot arm kit with all the necessary parts and servos, build it as a class, and then have your students build microcontrollers to control it.

As technology and computing classes become more common at every level of education, teachers (who often buy their own supplies) may be looking for projects to make the most of a minimal budget. How do you challenge a class of talented youngsters without breaking the bank? The answer to that one is simple: build a controllable robot arm and have each student build and program their own microcontroller.

From a parts perspective, the technology behind an Arduino is inexpensive and straightforward. With about $5 per person in materials, students can learn the basics of building and executing circuits while setting up their own hardware. The program you’ll need to write software for your Arduino (called an “integrated development environment” or IDE) is open source, meaning it’s free to use. Some Arduino IDEs run directly in your browser, making them even more accessible and easy to start with.

Once your students build their homemade Arduinos, the class can assemble the robot arm and learn to program it using the microcontrollers they built themselves. Each student can access and store Arduino programs (called “sketches”) remotely from a web browser, so students without a home computer can use the school’s machine, if necessary. This also makes it easy to save the project and come back to it over multiple days.

The robot arm is an ideal project for a classroom full of today’s curious, tech-savvy kids. Here are some reasons we think it works well:

  • Teaches valuable skills. Students will have the chance to learn technology skills, from electrical engineering and circuit building all the way to programming and execution.
  • Easily customizable. Teachers can customize this project to each student’s level, allowing a rare amount of personalized instruction. After building the board, students can program it at their own level. Those who want to spend a lot of time programming long movement sequences for the arm will be able to do so, while those who are just figuring out the programming aspect, or who struggle to do it on their own at home, can work on basic programming.
  • Practical, hands-on learning. The robot arm allows each student to present their work practically – a day in the classroom showing off what they’ve programmed the arm to do allows everyone to see each other’s work. This step takes the skills out of the realm of theory and into practice in a memorable way.
  • It’s just fun. This project is great because robots are cool. With the long-term goal of controlling a robot, most kids, especially tech-minded ones, will have no trouble staying motivated to work on their board and program.

Total Cost: $150 for a class of 20 (about $50 for a robot arm kit, plus $5/student in parts for the controller)

2. Thermostat Controller: Project for an Experienced Hobbyist

The project in brief: get an Arduino, a WiFi module, sensors, and a touchscreen display and build a connected, Internet of Things home thermostat that not only controls your HVAC but also displays info about the weather (both current and forecasted).

A thermostat controller is a great project for the home hobbyist who already has experience with microcontrollers and building circuits, and now wants to venture into practical applications.

As we lead more connected lives, smart devices grow ever more popular and relevant to our everyday business. This project will help the hobbyist get a grasp of how the Internet of Things (IoT) works, and how to use it to add practical functionality to your home. Your new thermostat, for instance, will be able to integrate and display weather forecasts for your area by tapping into weather data online. You’ll be able to control it remotely, ensuring that your home is the perfect temperature when you arrive.

Once you can connect devices to your home network and build programs that allow you to control them from your computer or smartphone, you’ll open a world of possibilities. Having a practical, concrete goal will also help motivate you to finish the project and work through difficulties.

Even if you’re not ready to start programming automatic responses, building a controllable thermostat is a solid, practical project. Even better, you can source your programming from someone who has already done it. That’s one of the great things about Arduino – its open source nature has grown a community that likes to share. You can almost always find someone who has done your project before, and you can use their work as a guide if you’re feeling unsure.

Total cost: $155 or less

3. Fingerprint Lock: Project for a Small Business

The project in brief: use a fingerprint scanner module and an Arduino microcontroller to give employees access to a break room or other private area, with no keys or numerical codes required.

Most small businesses have an area set aside for staff use, be it a break room, record room, or stock room. These areas should be a secure place to keep possessions and discuss staff issues, but employees may accidentally or intentionally compromise this security.

One solution to this security issue is to combine an Arduino, a motorized lock, and a fingerprint scanner module and create a fingerprint lock. Enroll your employees’ fingerprints, and they’ll have nothing to remember and no key to lose—just a simple swipe to gain access to all the employee-only areas. If an employee quits or is fired, you can easily revoke their credentials without having to share a new code with the remaining employees.

Fortunately for you (the small business owner who wants to try this approach), you don’t have to go it alone. There are dozens of tutorials like this one on how to build a fingerprint lock with an Arduino microcontroller. This project has a lot to offer a tech-minded business owner:

  • A challenge. The programming is more complex than in the previous projects. Assembling and testing several different components involves more user interaction than the previous examples.
  • Practicality. The components to make the fingerprint lock cost less than half of commercial fingerprint locks available to buy online. Add to this the eventual savings in time and security, and it becomes a practical investment for the entrepreneur with safety and privacy in mind.

Of course, this fingerprint lock is not a substitute for a professionally installed security system, so do your homework before adding a homemade fingerprint lock to deposit safes, front door access, and other sensitive areas.

Total cost: $90 to control an already-motorized lock.

4. Fab Collabs: Projects for Advanced Users

The project in brief: seek out other makers, artists, and DIY-ers and try to solve some of their problems or enhance each other’s practice. Once you have an idea, set a budget and work to find a solution that fits it.

For advanced users, those who have mastered the basic techniques and processes to bring ideas to life, choosing the right project is so personal. Instead of providing a standard project recommendation for all advanced users, ask yourself a few questions to help brainstorm new projects:

  • Are you trying to learn about a specific kind of technology or application?
  • Are you looking for a challenge?
  • What kind of topics interest you?
  • What other tools are accessible to you?

Seek out other makers who do interesting work as a way to spark creativity and inspiration. Learning to collaborate with other people who build and tinker, especially in fields outside of your expertise, is the best way to expand your skillset. One practical approach is to locate someone in your area whose work you admire (perhaps through a local college, workshop, art gallery, or industry event) and try to hatch a project that mixes your expertise. Maybe there’s a sculptor nearby who wants to automate their art or make an interactive exhibit, or a local theater that might want to integrate technology into a performance but has limited resources or expertise. Once you’ve identified a common goal, set a budget and challenge yourself to find a solution.

Total cost: variable depending on your collaborators and goals. Given the cost of parts for DIY-microcontroller setups, $150 is a nice medium – enough to produce a potentially great result, but still a constraint that will force your creative hand.

Education level and budget shouldn’t be obstacles as you build your programming and technology skills. Microcontrollers may be user-friendly enough for middle schoolers to enjoy, but they’re still powerful computing devices that perform important tasks. Look for obstacles and problems in your everyday life, and find creative ways to address them with affordable, versatile microcontrollers.

Zach Wendt

Manager, Applications Marketing Engineer

Zach Wendt is a mechanical engineer who enjoys writing about how electronic components can best be applied in projects. He works for Arrow Electronics, a major supplier of microcontroller products