17 Incredible DIY Gadget Projects

boy looking closely at an invention
JERRY LAMPEN/AFP/Getty Images

We do love a good gadget project. From tinkering with Raspberry Pi microcomputers to automating our own homes, to coming up with cool renewable energy projects...we can't stay away.

1. Raspberry Pi Hack Unlocks Door When It Hears a Dog's Bark

pi-rex dog door image

David Hunt / Video screen capture

Maker David Hunt created a clever hack for a door for dog owners who are tired of getting up to let Fido outside. Called Pi-Rex, it is a bark-activated (note, not voice activated, but bark activated) door.

2. Make a Battery with Spare Change

diy batteries with pennies

via The King of Random

This project from King of Random teaches you how to build a battery with the spare change in your pocket. In just a few steps, a handful of pennies can power a small calculator or an LED bulb.

3. Make a Small Wind Turbine That Kids Can Help Build

handmade wind turbine

masynmachien

This project from masynmachien via Instructables is meant to be easy enough for older kids and adults to do without too much experience. It's a great way to brush up on your own skills or teach renewable energy basics to kids.

4. Make a Steampunk Solar Night Light in 10 Steps

solar lantern on a night table

Winged Fist

From Winged Fist on Instructables, learn how to cheaply make a Steampunk solar night light for your home. Because... why not!

5. Make an Emergency Light Powered by Fire and Water

tealight LED image

Joohansson

This DIY from Joohansson on Instructables is not only a neat project for creating an emergency light but also an excellent project for kids learning about science.

6. Turn an Old Laptop Screen Into a Stand-Alone Monitor

laptop monitor

augustoerico

We often hear of how using a second monitor can boost work efficiency by splitting up tasks between two screens. This project from augustoerico at Instructables gives you a neat DIY way to get a second monitor hooked up while also re-purposing an old laptop and giving it new life.

7. Home Brewer Makes a Digital Tap List Using Raspberry Pi

kegerator sadly without raspberry pi display

Micah Maziar / Flickr / CC BY-NC-SA 2.0

A first-time tinkerer going by the name SchrodingersDrunk on Reddit has rigged up this cool digital tap list display using our favorite DIY platform, Raspberry Pi, and a 19" Samsung monitor. For those who want to follow in his footsteps, he's made the project available on GitHub and answers questions over on Reddit.

8. Make a Hand-Crank Rechargeable Flash Light

hand crank flashlight

brunoip

From brunoip, this DIY project takes on a gadget that can easily be bought in a store, but instead lets you use materials you already have to make something useful. It's also a great way to build your maker skills.

9. How to Make a 35-Watt Solar Panel out of Broken Solar Cells

broken solar cell

mattfelice

Provided by mattfelice, this project is totally adaptable to the amount and size of solar cells you may have on hand, and the best part is that those discarded cells won't become e-waste, but a functional, clean energy-producing solar panel instead.

10. Make a Simple Microbial Fuel Cell

microbial fuel cell 2

drdan152

From drdan152 on Instructables, make a microbial fuel cell—a technology that harvests electrons that are a byproduct of bacteria breaking down organic matter to produce electricity—at home. This project lets you get up close with the science behind microbial fuel cells and learn about this type of renewable energy technology.

11. How to Make a Water Battery

water bottle battery

Roy02

With a few materials and a little bit of time, Roy02 shows us how to put together a working battery made from water. This project could be used to add a little charge to your smartphone or be a fun way to introduce battery chemistry to kids.

12. Make a Solar-Powered Bike Light From a Deodorant Stick

finished deodorant bike light

sudhu_tewari

Use an empty deodorant can for building a solar-powered bike light. The hack from sudhu_tewari is simple, cheap, and, we assume, great smelling!

13. Make a Bicycle Powered Generator in 9 Steps

bike generator

abemckay

This great project for making your own bicycle-powered generator for charging your electronics with clean energy was provided by abemckay on Instructables. Great for every day or as an emergency power supply.

14. How to Transform an Antique Portable Radio Into a Modern Bluetooth Speaker

antique portable radio

ke4mcl

This cool project from ke4mcl shows us how to take an antique portable radio you might find at a flea market or yard sale and give it a new modern life by making it into a Bluetooth speaker. Once transformed, this gadget can pair with your smartphone or iPod and play your tunes wherever you take it.

15. Make a Portable Solar Phone Charger for $5

solar charger side

ASCAS

Learn to make a solar-powered phone charger for only $5 thanks to this DIY from ASCAS on Instructables. It's as small as a smartphone and doesn't include a back-up battery, which is more environmentally friendly. ASCAS tested the device on both Apple and Android devices and it worked well with both.

16. Make a Fire-Powered Smartphone Charger

smartphone charger powered by fire

Joohansson

This portable DIY charger from Joohansson will let you keep your smartphone topped up with the heat from your camp stove or other heat source. It could be used to power other things like LED lights or a small fan.

17. How to Build Your Own Solar-Powered Plane

solar plane photo

jeffmazter406

This instructable from jeffmazter406 includes not only step-by-step instructions and photos but also links you to two PowerPoint presentations by Texas A&M; University to help walk you through.