Pavlov’s Cat is a training device that rewards your cat for coming to the food dispenser when a certain sound is played. It effectively conditions your cat to respond to specific stimuli and establish them as keywords, often making it easier to have those keywords correspond to different actions, such as “sit” or “come”, since food is associated with them.

The project integrates a basic food dispenser with Arduino’s IoT platform to automate food dispensing and play sounds to make it a “smart” dispenser. Much of the code is provided, making this primarily a hardware integration project. This is a fantastic opportunity to experiment with laser cutters and cardboard boxes or gain a basic understanding of Arduino and IoT.

• Difficulty: Beginner
• Designer: Arduino_Genuino
• Project site: Arduino Docs
• Core components: Arduino Nano, servo, buzzer module

This trashcan is smart indeed! This sensor-based bin allows you to “open” your trashcan without actually touching the lid, which is perfect if you have your hands full or simply don’t want to make contact with a dirty lid.

The Arduino-based project with an ultrasonic sensor is explained step by step, with links to the code and parts used. Positive comments show that at least a few have been successfully built.

• Difficulty: Beginner
• Designer: Indian LifeHacker
• Project site: YouTube
• Core components: Arduino Uno, ultrasonic sensor, servos, dustbin

If you’re the type of plant owner who’s admittedly a bit forgetful about watering your plants, this Arduino system will help sort it out for you so your plants stay healthy and happy. The moisture sensor in the project allows the water pump to be triggered so that the plants get their water supply.

This is a creative and compact project, ideal for small living spaces. In addition to all the necessary information to carry out this project, there’s a sketch that depicts the system’s functionality.

• Difficulty: Intermediate
• Designer: benrbill
• Project site: Instructables
• Core components: Arduino Uno, soil moisture sensor, breadboard, 12-V pump

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Humans have valued security since ancient times, with early mechanical locks appearing in ancient Egypt over 6,000 years ago. However, in our increasingly modern world, digitally controlled locks are becoming the norm. This RFID lock system is perfect for a pet project. It uses an Arduino, RFID reader, 4×4 keypad, LEDs, and a buzzer to complete a full security system.

The system communicates using the I2C protocol, allowing the Arduino to effectively interface with both the RFID reader and keyboard. For the lock to open, you’ll first need to scan your RFID chip or card, then type in your passcode – providing two layers of protection. The project itself doesn’t contain a set housing for the circuit and electronics, but could be a great addition if you decide to try it out.

• Difficulty: Intermediate
• Designer: Aqib
• Project site: Hackster
• Core components: Arduino Uno, RFID reader, 4×4 keypad, servo, I2C LCD

When you’re injured, stuck in bed, or feeling just a bit lazy, this Arduino remote control light switch is the perfect solution for a simple way to turn a light on or off at a distance in your room.

The project’s servo motor mechanism allows the light to switch on and off automatically, and the creator has provided all necessary CAD files, code, and instructions. Note that you’ll need access to a 3D printer to make some of the project’s parts, so different skills will be put to the test.

• Difficulty: Intermediate
• Designer: alanmerritt
• Project site: Instructables
• Core components: Arduino Uno, additional Arduino board (any), 3D printed parts

Having an easily portable humidifier is great for houses and apartments that get very dry, especially during winter when the heating can really dry things out. The portability factor makes it simple to move from room to room, should there be a need to do so (or you could build a couple of these).

The project is straightforward and includes a video tutorial. Since the humidifier is also automatic, it helps that you don’t have to constantly check the moisture levels, which can often be an annoying aspect of standard humidifiers.

• Difficulty: Intermediate
• Designer: Debasis Parida
• Project site: Circuit Digest
• Core components: Arduino Nano, ultrasonic humidifier, 5-V relay, electrolytic capacitor

Hydroponic towers are a fascinating system for growing plants at home. You can cultivate your own food by replacing soil with water with dissolved nutrients. The compact systems can even be stored in the house under artificial light, eliminating potential weather variations that affect the plants’ growth. This project details how you can build your tower and automate it using Arduino!

This hydroponics system is based on just a few main components: an Arduino Nano, a water pump, and an optional sensor. The pump will distribute water up the column of the tower and release a stream down through the roots. While optional, the quality sensor measures the amount of dissolved nutrients dissolved in the water, making it easy to stay on top of your plant’s needs. It can be programmed to activate the pump at set times of day or, by adding a water level sensor, triggered by a certain moisture threshold.

• Difficulty: Advanced
• Designer: laszlodaniel (printable files reuploaded by chrisebryan)
• Project sites: Printables, GitHub
• Core components: Arduino Nano, water pump, 3D printed parts

Keep Growing

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Let’s be honest, who wouldn’t want to automate all those pesky around-the-home tasks, such as turning off the lights? While remote control of household appliances is a mere comfort to most, for someone with a disability, it can be a real necessity for independence. While there are several projects around that dive into home automation, this one relies on voice control, which just makes everything so much cooler.

To complete this project, you’ll need to know how to solder electronics and how to assemble components on a universal board. The instructions and voice commands will be converted using an app (found on GitHub) and directed to the device through the Bluetooth module. You’ll find full, detailed instructions on the project page.

• Difficulty: Intermediate
• Designer: Jobit Joseph
• Project sites: Circuit Digest, GitHub
• Core components: Arduino Nano, Bluetooth module, 5-V power supply module, relays, LEDs

The perfect espresso is the culmination of a variety of factors, including but not limited to bean type, roast, grind, quantity, tamping pressure, and finally, consistent temperature and pressure. The last two are nearly impossible on a budget machine, but an engineering student from the UK set out to meet the challenge with technology. He deconstructed a budget espresso machine for some of the basic parts and housing, adding in a thermocouple with two Arduinos, and put together this awesome machine.

The entire project is open source with a parts list, instructions, and a lengthy guide to help you out if you attempt it. Additionally, the machine uses some 3D printed parts for certain housings, as well as some new pumps. The total cost of the machine was just south of $300 but delivered the performance of a $900 machine. If espresso isn’t up your alley, check out this cool laser-cut, automated tea maker.

• Difficulty: Advanced
• Designer: Zack Moss
• Project site: Hackaday
• Core components: Arduino Uno (2x), thermocouple and shield, liquid connection hardware

Although cars nowadays include numerous fancy gadgets that once were optional, not all of us are driving around with the latest car model… or even one less than ten years old. This is one of the most convenient tools to install on your car, especially if you regularly have to squeeze your wheels into tight spaces.

The system is simple yet clever. It’s based on an ultrasonic sensor that can calculate the distance to an object by emitting ultrasound waves. When those waves hit an object, some get reflected back to the sensor in an amount of time that’s related to the distance the waves had to travel. To make it functional, it’ll also need a buzzer that will generate a sound when the sensor tells Arduino that you’re approaching an obstacle.

• Difficulty: Beginner
• Designer: jackaless
• Project site: Arduino Project Hub
• Core components: Arduino Uno, ultrasonic sensor, buzzer

Want to diagnose broken wiring, plug pin connections, and more? With this cable tracer, you can test over 10 different cable types, including RJ45, USB-B/B3, USB-A/A3, USB-C, Mini-USB, Micro-USB, and Micro3. It’s possible to perform the diagnosis manually or automatically when plugging in a cable.

In this project, you’ll first need to load the code into the Arduino, then 3D print the required parts, which you’ll find on Thingiverse. After that, you’ll build your own tracer cable shield. You can purchase the complete and assembled kit for ~$155 at the Tindie store, or just the shield for ~$44. If you decide to venture into using universal boards or making your own custom PCBs, the author warns that it may take around 20 hours of soldering. In the printing instructions, it’s recommended to use 20% infill. Further assembly instructions can be found on Instructables.

• Difficulty: Intermediate
• Designer: TechKiwiGadgets
• Project site: Instructables
• Core components: Arduino Mega, shield, 3D printed parts, 2.8-inch TFT touchscreen, USB-A cable, USB-A charger, header connector strips

Adjustable bicycle suspensions are great for different types of terrain, but having to stop to adjust or even take your hands off the handlebars isn’t very practical. With this project, you’ll have a smart bike that will do the job on its own to be in the best shape for the ride.

The system uses 5-second intervals that are labeled and analyzed by AI through Edge Impulse Studio, which returns a model that classifies up to five different settings, including idle, medium, irregular, smooth, and sprint. It’s necessary to create a user and register if it’s your first time on it, then open a new project and select the accelerometer data.

• Difficulty: Intermediate
• Designer: Jallson S
• Project site: Instructables
• Core components: Arduino Nano 33 BLE Sense, lithium ion battery, smartphone, mini-servo SG90, 3D printed parts

No one likes to be in an overheated environment, and it can even be dangerous if temperatures rise too high. However, air conditioners are not always cheap or portable, so this powerful project can help you stay cool. You can add ice to the bucket of water to make the experience even more refreshing.

The device operates using water’s natural phase change, utilizing a conveyor belt to continuously absorb heat from the air to maintain a cool environment. You can view the assembly details in the circuit diagram available on Hackster.

• Difficulty: Advanced
• Designer: Jerry Miao
• Project site: Hackster
• Core components: Arduino Uno, stepper motor, 16×2 LCD, rotary encoder, 3D printed parts

This next project shows that it’s possible to recycle PET bottles at home to make 3D printable filament. The instructions for this project are clear and detailed. However, it will be necessary to adapt your hot end so that the plastic can enter smoothly.

To make this, you’ll need some tools, including a multimeter, soldering iron, screwdriver, and access to a 3D printer or a printing service. The project creator left recommendations for each of the parts and tools used, and the printable models are available on the blog. For the bottle to be cut correctly, it’s important to smooth the surface by carefully deforming it with heat. You’ll want to increase the flow rate to compensate for the density, as the filament created is hollow inside.

• Difficulty: Intermediate
• Designer: thediylife
• Project site: Instructables
• Core components: Arduino Pro Mini, NEMA17 stepper motor, stepper motor driver, 3D printer hot end, 2020 V-Slot profile, I2C OLED display, 3D printed parts

Our planet is polluted by trash every day, and this problem needs smart solutions like this next project. Here, the rubbish is classified and separated by artificial intelligence into baskets. Based on the noise it makes when falling into the bin, the item is then sorted into one of four different baskets.

The project author notes that they used 1 kg of PLA to make the 3D printed parts, corresponding to about 20% of the machine’s parts. Another 20% of the parts are made of acrylic, 55% are made of aluminum, and the remaining 5% come from various materials. Although the classification system isn’t perfect, it’s a device with incredible potential.

• Difficulty: Advanced
• Designer: Samuel Alexander
• Project sites: Hackster, Hackaday
• Core components: Arduino Nano 33 BLE Sense, lithium battery, 3D printed parts, neodymium magnets, A3144 hall sensor, NEMA17 stepper motor, servo motor, transparent acrylic, 2020 aluminum profile

If you’re a maker, you probably use at least one design software. If you’re looking for ways to improve your workflow with these kinds of programs, look no further. Orbion is a 3D space mouse that will improve your ability to work and navigate within the virtual 3D space. Some of the most famous applications that are compatible with Orbion include SolidWorks, Fusion, Blender, FreeCAD, ZBrush, and many more.

To recreate this build yourself, you’ll not only need an Arduino Pro Micro with the ATMEL32U4 processor but also a joystick with a 4-mm shaft, an encoder, and OLEDs. The joystick will detect the movement of the hand and the encoder will convert it into data processed by the Arduino. The OLED screen displays some information about the space mouse, such as the mode list.

The most difficult part of the project is the wire management, so it’s ideal to have previous soldering experience. Moreover, the creator warns against ABS, as it’s prone to shrinking, making assembly more difficult or even impossible. Instead, a couple of makers reported good results with carbon fiber-reinforced PLA.

• Difficulty: Advanced
• Designer: FaqTotum
• Project sites: Printables, GitHub
• Core components: Arduino Pro Micro, joystick, encoder, I2C OLED, 3D printed parts

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Cyclops is a little yet powerful personal assistant robot that you can customize to your needs. You can entrust it with your time management, note-taking, emotion detection, and much more. If you want to save a few bucks, you can build its housing from some cardboard sheets, or you can download the model from the Tinkercad page of the project and 3D print it.

This cute robot is voice-activated, so you can ask it to play music or games, take photos, and much more. When you give it a command, the Arduino processes data, and when it’s ready to answer, its little pyramid top spins. Since it’s your own personal assistant, you can add whatever components and Arduino libraries to it you’d like, such as a temperature sensor to keep an eye on the room temperature. What will you add?

• Difficulty: Intermediate
• Designer: Mandred Tech
• Project site: Instructables
• Core components: Arduino Uno, servo motor, LCD screen, potentiometer

It can be quite boring to fold your laundry, especially shirts. You’ll find tons of t-shirt folding products on the market, but unfortunately, most of them are manual.

This project is an autonomous t-shirt folding robot that only needs you to place your clothes on it. Using FoldiMate as their inspiration, a couple of engineering students created this prototype as a relatively affordable product.

You can build the robot’s body using 3D printed and laser cut parts, motors, and a couple of other electronics, all powered by an Arduino. If you want to know how well this robot works, take a look for yourself!

• Difficulty: Advanced
• Designer: Stefano Pontoglio
• Project site: Instructables
• Core components: Arduino Uno, servo motor, stepper motors, motor drivers, plywood, 3D printed parts

There are many models of robotic arms out there, but the vast majority of them don’t have precise control or are too expensive to be worth it. This project aims to build not only a precise robotic arm but also do so on a reduced budget. The simple design of the robot makes it very versatile for any application where you may need a third hand, like recreational tasks or even small manipulations.

Costing only around $60 to build, you’ll just need to print the plastic casing and buy some other electronic parts, a complete list of which can be found on YouTube. You’ll also need a little patience and some skills to assemble everything, as the instructions are not newcomer-friendly, but the author has posted lots of resources and a video detailing his design process.

• Difficulty: Advanced
• Designer: jonserra
• Project sites: Arduino Project Hub, Thingiverse
• Core components: Arduino Leonardo, servo motors, servo driver, 3D printed parts

While anyone can have a mower, the designer of this project provides everything you need to up your lawn care game. Mowerino is an autonomous lawn mower robot that tends to your lawn. It even features a Bluetooth remote control mode, which allows you to control its movements and blades using a mobile app.

The parts of Mowerino are mostly 3D printed, and the design is optimized to house all the electronics and components to make it the perfect cutting machine. Its features include easily avoiding obstacles and displaying its battery charge using a smiley or sad face on a matrix LED display. In a way, this gives your Mowerino some personality.

• Difficulty: Advanced
• Designer: salmec
• Project sites: Arduino Project Hub, Hackster
• Core components: Arduino Mega, motor driver board module, ultrasonic sensors, angle tilt sensor, lawn mower blades

If you’re looking for a robot companion, a remote-controlled camera operator, a search and rescue device, or something capable of all three, then look no further! Meet Tishka, a six-legged pal that can maneuver over difficult and rough terrain and does so with a lot of personality thanks to its articulated ears.

This robot is not very small, but it has a mounted camera that can be used for exploration or even for filmmaking. The complete list of required materials was posted by the maker on the Thingiverse page, along with an assembly video. The commentary is in Russian, but if you have background knowledge of robotics assembly, you should be able to follow along just fine. The same maker has posted several other robot projects, like the APC-1, which you can also draw inspiration from.

• Difficulty: Advanced
• Designer: AlexKorvin
• Project site: Thingiverse
• Core components: Arduino Mega, expansion board for Arduino, wireless Playstation 2 Gamepad, servos, 3D printed parts

Artificial intelligence is increasingly present in our lives, but it’s nothing like what we imagined a few years ago. For some, this hasn’t caused a personal existential crisis, but for others, it’s a strange feeling to talk into a hockey puck with access to infinite knowledge (looking at you, Alexa). This project aims to put a friendly face to the current generation of lifeless robotic assistants while also repurposing outdated electronics.

With animatronic eyes and a sound-signal “mouth” displayed on a CRT monitor, it’s not hard for you to think, if only for a moment, that this machine really is alive. There is even a sensor to track the user’s face and maintain eye contact. Of course, you can replace the CRT monitor with an LCD to make the assembly much simpler. Check out the video uploaded by the creator to see this impressive build in action. Apparently, an upgrade with expressive eyebrow movements is in the works.

• Difficulty: Advanced
• Designer: Thomas Burns
• Project sites: Hackster, YouTube
• Core components: Arduino Mega, Amazon Alexa Echo Dot module, 5-inch display, audio amplifier, servo driver, 3D printed parts

Water is an indispensable resource for all of us, and having a level meter that facilitates its management can be essential, especially for the forgetful folks among us. Whether for a pet’s water supply, a hydroponic garden, or your own small reservoir, this project will give you full control of the levels without having to worry about wires. The device also has an alarm to be sure you won’t miss a drought.

An ultrasonic sensor measures the water level, avoiding direct contact with the water and possible contamination. This is very important if you plan on drinking the supply. According to the designer, while other similar sensors cost around $70 on Amazon, they spent just $15 to assemble everything.

• Difficulty: Beginner
• Designer: Manusha_Ramanayake
• Project site: Arduino Project Hub
• Core components: Arduino Nano, HC-12 wireless module, ultrasonic sensor, 16×2 LCD

Pomodoro Tomato is the ideal project for those who want to maximize their productivity. There are many apps and websites that let you use their timers for the Pomodoro Technique. However, using these devices can make you more distracted than productive.

The Pomodoro Tomato has a 7-segment display for the timer that counts down while you work. Even if you’re engrossed in your task, you’ll be alerted by its buzzer once the time runs out. You can switch between the timer for work and a break using the button. In addition, the tomato’s design makes it a cute desk accessory.

• Difficulty: Beginner
• Designer: prusteen
• Project site: Instructables
• Core components: Arduino Nano, real-time clock module, buzzer, button, 7-segment display, breadboard, 3D printed parts

We often miss our alarm or oversleep by hitting snooze, even with multiple back-to-back alarms. No matter the device, be it your phone or alarm clock, you can easily shut off the alarm and go back to the land of dreams.

This project is the perfect alarm clock to tackle all these snoozing issues. Once you hear the alarm, you have to push the snooze button and stay in front of it for an entire minute to stop the buzzer. If you believe that a minute isn’t enough time to stop you from going back to bed, you can set a longer duration in the code.

The maker used balsa wood to make a compact enclosure, although you can easily design and 3D print your own instead. Once your device is ready, you’ll be ready to wake up and start your day on time.

• Difficulty: Beginner
• Designer: galoebn
• Project sites: Hackster, Arduino Project Hub
• Core components: Arduino Mega or Nano Every, motion sensor, clock module, buzzer

This Arduino-controlled Nixie clock gives retro vibes while emphasizing keeping up with the times. The Arduino chip keeps the time and feeds to the opto-isolation chip, which is responsible for controlling the tubes. This is a great project to learn more about hardware wiring.

These tubes work similarly to incandescent lightbulbs, where a voltage is applied to an anode and cathode inside a sealed glass tube. However, in Nixie tubes, each number corresponds to a different cathode. Applying voltage to a specific cathode will make the corresponding number glow. Additionally, a different process occurs due to a significantly high voltage being applied, which produces a cold-cathode glow discharge, a sort of ghostly glow.

• Difficulty: Intermediate
• Designer: whitebank
• Project sites: Arduino Project Hub, Hackster
• Core components: Arduino Uno, Nixie tubes, clock module, opto-coupler chip, DC step-up module

A DIY version of a smartwatch, this Arduino-controlled device will send notifications to you from your iPhone with the help of Bluetooth and, as a bonus, will automatically synchronize the time when daylight savings occurs.

If you’re interested in taking this cool watch with you on the go, the project’s creator has provided all necessary directions and sources in a clear manner. Note that you’ll need a 3D printer and some experience with a soldering iron.

• Difficulty: Advanced
• Designer: Karlstrom
• Project site: Arduino Project Hub
• Core components: Arduino Pro Mini, Adafruit Bluetooth LE, Adafruit LED display, lithium ion battery, USB connectors, USB cable, SparkFun LiPo Charger, SparkFun FTDI

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One of the most fascinating things about technology is the ability to tear down boundaries we never thought possible. This is one of those fantastic projects that unlock new possibilities. As a wearable glove, it converts hand gestures to text and speech by sending movement data to a phone application.

The main component of this glove is the accelerometer and the flex sensor. The first measures the movements of the hand in the X, Y, and Z axes, while the second measures the bending of the fingers through changes in the resistance. The Arduino Nano processes the data collected from the sensors which then get transmitted to a phone via Bluetooth and converted into the corresponding letters and text.

The most involved parts of this build are the soldering process and the app development. The sensors have delicate pins that can easily break, so be gentle with the soldering iron. For the app, you can either develop your own with the MIT App Inventor or reach out to the creator directly (his email is in the comments) so he can send you his application.

• Difficulty: Advanced
• Designer: ayooluwa98
• Project site: Arduino Project Hub
• Core components: Arduino Nano, accelerometer, flex sensor, inertial measurement unit, HC-05 Bluetooth module

Get-Fit is an open-source wearable fitness tracker that keeps count of your exercise reps plus the calories you burn during them. It can identify and differentiate between several exercises, which are made possible by machine learning (ML).

Before you start working out, you need to train the ML model for your tracker. Edge Impulse is the perfect ML development tool to do so. You can easily follow the guide on Hackster to train your Get-Fit. After this, you can build the web-based user interface that displays information and lets you interact with it. Once all is ready, 3D print your parts, assemble your components, and take off on your fitness journey.

If you want to further develop the project and add more features and functionalities, you can do so. Regardless, the makers have shared some future improvements that will come soon, so keep an eye out for updates.

• Difficulty: Advanced
• Designer: CodersCafeTech
• Project sites: Instructables, Hackster
• Core components: Arduino Nano 33 BLE Sense, LiPo battery

If you’re taking multiple medications daily or are in charge of someone who needs to do so, you know the challenge of making sure it’s all organized correctly so that the right pill is taken at the right time. This helpful Arduino project allows you to take some of that stress away, as it’s meant to be configured and tracked via an app to ensure correct and timely dosage intake.

Plenty of detailed instructions and video footage make it easy to follow along with the project. This is a somewhat advanced project that requires 3D printing and some soldering work, so keep that in mind.

• Difficulty: Advanced
• Designer: Mireia Flores, Isabel Fernández Palou, Javier Poveda, Pablo Fernández Silva, Jaime Laborda
• Project site: Hackster
• Core components: Arduino Mega, AVR-IoT WA development board, micro servo motor, LCD touch display, speaker