Tag Archives: Arduino Pro Mini

Creating an elaborate BB-8 replica

Inspired by BB-8, one Maker is bringing some Star Wars magic of his own to life with a ball-balancing robot. 

It didn’t take long for everyone (ourselves included) to fall in love with JJ Abrams’s adorable new BB-8 droids, who have stolen much of the Star Wars: The Force Awakens spotlight even before hitting theaters. As you can imagine, countless fans are already counting down the days before the arrival of what will surely be a holiday best-selling robot toy this year. However, instead of waiting, a number of Makers like James Burton have decided to take it into their own hands by devising fully-functioning replicas.


Whereas the actual character is comprised of two separate parts (a remote-controlled body and a separately remote-controlled head), Burton’s latest project consists of a balancing robot that sits atop a 500mm diameter polysyrene ball serving as its body. This lightweight material gives more relative inertia, and therefore, stability for the droid positioned on top.

As seen when the robotic creature made its debut on stage in Anaheim, the “real” BB-8 features a robotic ball for its body with an independently-moving head that doesn’t fall off, which is clearly the work of physics and maybe some magnets?


And this Maker has taken a somewhat similar approach. Gyroscopes and accelerometers from SparkFun are tasked with maintaining the ball-balancing robot’s equilibrium. Meanwhile, the Maker has employed an Arduino Pro Mini 5V (ATmega328), a couple motor drivers, a few DC motors, a level shifter, and of course, a set of omni wheels for multi-directional movement. These components are all mounted to a 3D-printed chassis and housed inside a 300mm acrylic hemisphere.


With that working well, he also tried to make it remote-controlled. This required the addition of an RC receiver along with another Arduino that offsets the gyro value to make it roll in one direction. For a while, BB-8 was only capable of running on carpet; however, as you can imagine when trying to demonstrate the project at shows and other conventions, carrying around a small piece of rug could be quite tedious. So in an effort to solve this problem, Burton improved his design with some trial-and-error by adding ball bearings inside the hollow sphere, thereby emulating the slowness of carpet.


With a little more 3D printing for additional details, such as its eyes, and some airbrushing of its exterior, Burton was just about complete with his impressive project — that is at least, until he begins a second version. For those of you who are familiar with this Maker’s work, it should come as no surprise that he has put together an extremely elaborate playlist of steps, which you can find below. Interested? You can find the project and its entire code on Github.

Vinduino is a wine grower’s water saving project

Vineyard + Arduino = Vinduino

Given the current water crisis affecting the Golden State, farmers are constantly seeking alternative ways to reduce agricultural consumption. Take Reinier van der Lee, for example, who has developed a solution that can cut H2O use by up to 25%. And for that reason alone, it makes for an excellent Hackaday Prize entry.


The project, which is aptly named Vinduino, began as a necessity to better manage irrigation on his Southern California vineyard. However, it’s not just the U.S. west coast that is impacted by drought. There are 36 countries, spanning from Africa to India, that are facing similar situations due to lack of rainfall. With this in mind, van der Lee hopes that his DIY system can reach a widespread audience by making it open source, affordable, and easy to build.

As a whole, the system is comprised of calibrated gypsum soil moisture sensors, a handheld sensor reader and a solar-powered remote platform. Based on an Arduino Pro Mini (ATmega328), the Vinduino is equipped with three inputs for soil moisture sensors, an RTC module, a load switch, irrigation valve control, and wireless communication via either a ESP8266 Wi-Fi or a long-range RF module. Most recently, the Maker installed extra gypsum sensors and implemented a 4G hotspot for Internet access on his vineyard by connecting to the ESP8266.


“Using a single soil moisture sensor, you can determine when to start irrigation, but overwatering is hard to avoid,” van der Lee writes. “By the time the irrigation water reaches the sensor, the layer above is saturated and likely there is more water than the plant can consume. The surplus water will now seep below the root zone, out of reach of the plant, taking unused nutrients with it as well.”

Instead, this problem was solved by using three sensors. The lowest most sensor is placed below the roots, so it should never go off. If it does, this means that the plant is not taking in all the water, and subsequently, the output can be reduced. The two sensors above it monitor the H2O as it transitions through the soil, and adjust the water amount and interval frequency accordingly.


With multiple sensors located at various depths, users can actually control irrigation to not exceed the active root zone, thereby saving water. Rather than have to irrigate for an extended amount time and with long periods of rest in between, Vinduino allows for much shorter, more frequent irrigation cycles. The result? The plants will be able to absorb the water before it even has a chance to reach the level below the active root zone. It is important to keep in mind, though, that different crops call for different depths. For instance, recommended sensor depths for grape vines are 24, 48 and 60 inches.

Resistive sensors, like gypsum sensors, need to be excited with short pulses of alternating current to avoid electrolysis effects. The Vinduino interface alternates currents through the sensor, while a pair of analog inputs are utilized to measure voltages over the bridge. This compensates for differences in battery supply voltage, as well as sensor bias voltage.


Since the sensors are connected together through a soil resistance path, multi-sensor measurements can only be achieved if the sensors are disconnected when not in use. For this, Vinduino employs regular 2N7000 FETs. The handheld reader is capable of only measuring one sensor at a time, thus can use a simpler interface circuit without FET switches.

For vineyards, irrigation reduction is sometimes practiced in the days leading up to harvest in order to get highly-concentrated wine grapes. The idea is that the best wines come from vines that have suffered water stress. In case you’re interested in van der Lee’s status, his vines are doing well under the new irrigation regime.

Intrigued? Check out the Maker’s entire project on Hackaday.io here.

This three-axis motion sensor gyroscope is based on an Arduino Pro Mini

Maker Martin Cote has developed a three-axis motion sensor gyroscope that enables you to track head or arm movement, then reproduce it on servos. 

Initially conceived for head-tracking FPV goggles, Martin Cote has created a three-axis motion sensor gyroscope based on an Arduino Pro Mini (ATmega328). Applicable in a wide range of settings, users can track the movement of the head or arm, and replicate it on a set of servos.


Available in two different versions, both wired (Iota) and wireless (Z-ita), the gyroscope is ideal for Makers seeking an inexpensive head-tracking system yet are not comfortable with the advanced programming of accelerometers. Sample use cases include robotics, remote-controlled toys, gaming and interfacing with computers.


First, Iota provides users with the ability to control mini servos that reproduce movement on three axes, as well as reverse the direction of the servos to act as a stabilizer. Measuring just 1” x 3″ in size, the super small and lightweight unit can be easily integrated into any project. Meanwhile, Z-ita does pretty much the same thing but wirelessly within a range of 30 to 50. This set comes with the Ita receiver, which transmits the signals to the servos, as well as a battery capable of lasting of over two hours. What’s more, it offers a selection of 16 channels at the frequency of 2.4Ghz, and allows more than one to be used at a time.


“You want to use the accelerometer signals to another type of application? Get the Iota or Z-ita set and plug it into your Arduino MCU according to the video and use the sketch file provided (which you can adapt to your needs), and look for new possibilities to suit your needs.”

Interested? Head over to Kickstarter page, where Cote has already well exceeded his initial goal of $408. Shipment is expected to begin in October 2015. 

Creating a dual-mode compass with Arduino and NeoPixels

With the push of a button on this DIY compass, a user can select between north tracking and heading indicator modes.

After coming across a video of fellow Maker David Ratliff’s NeoPixel compass project on YouTube, Philo Mech had wanted to create a dual-mode one of his own for quite some time.


The compass is comprised of a 12-LED NeoPixel ring (which will be swapped out for 16-LED in the next iteration) along with an Arduino Pro Mini (ATmega328) that drives an accelerometer/magnetometer breakout board, and a momentary pushbutton tasked with shifting between both modes. Meanwhile, the device supports 5V voltage regulation circuitry for managing the Pro Mini and NeoPixel ring.


This current version boasts two very useful modes: one to track the whereabouts of north, the other to determine the direction that the user is heading. When in the first mode, north is indicated by a red LED sandwiched between two yellow lights. As the Maker demonstrates in his video, it should match up fairly well to a standard compass arrow. While the range of degrees is not yet perfect, Philo Mech admits, it is still fairly close. The latter mode, which perhaps is a bit more helpful, reveals a different splash background with a red light denoting the cardinal direction that the user is going.

As the Maker reveals, future models will not only employ a 16-pixel ring but will also provide finer degrees of directional change and better compensate for tilting. In the meantime, you can see it in action below.

Build your own activity monitor with Arduino

RetroBand is an open source, ATmega328 powered activity tracker that pairs with your smartphone.

Over the last couple of years, the wearable technology market has experienced tremendous growth, particularly when it comes to health and wellness. When thinking of the latest and greatest fitness bands, companies like Jawbone, Fitbit and Nike typically pop into mind. However, despite its surge in popularity, the cost of owning such a device has become as a major barrier in adoption. That’s exactly why an Instructables user “GodsTale” has decided to take it upon himself to create a DIY activity tracker using an Arduino Pro Mini (ATmega328), a Bluetooth module, an accelerometer, a LiPo battery and some custom software from his smartphone, all housed inside a 3D-printed case. Total cost: Less than $30.


The Maker, who recently designed the RetroWatch, says that the device he calls the RetroBand has only one feature: collecting data through its built-in accelerometer and relaying it to his smartphone. An accompanying mobile app (available on Google Play) then analyzes the accelerometer data and provides an output of calories burned as well as steps taken to the user. Subsequently, GodsTale urges that “this shouldn’t be called a ‘smart band’ since it has only simple features.”

The Android app is comprised of four parts: an Android UI, a Bluetooth manager, a background service and an algorithm section.

“The Android app check steps using collected data provided from RetroBand Arduino. The algorithm of the app is not that complicated. If you have much experience to this area, you can replace it with your own algorithm. The app saves the calorie data, so you can see the progress it in a monthly/daily/hourly graph form,” GodsTale explains.


The Maker has established a system where the accelerometer data is checked 20 times a second by the device. The gadget then transfers data to the smartphone application once a second. From there, the Android app receives the information in a matter of two seconds and determines an interval that the user’s movement increases dramatically — the number of movement increases is the step count. Beyond that, the app calculates calories burned based on user’s weight and steps, along with accumulated monthly, daily and hourly data.

At the brains of the operation lies an ATmega328. The Maker selected the Pro Mini board as “it works well with 3.7V lithium-polymer battery and its size.” He also employed a USB-to-UART converter to upload its source code.


One drawback of the RetroBand is that it cannot save data given its limited memory capacity, which is the reason for pairing it to a smartphone. GodsTale has made his code available on GitHub, while its Android app can be downloaded from the Play Store. Want to save some money on your next wearable? Head over to the project’s official page here to get started.

This IoT device will help detect heatstroke during road races

Telefonica and GFI Informatique have developed a wearable device that will be able to stop heatstroke before it occurs.

Recent studies have shown that long distance running involves a slightly increased risk of death but it’s heatstroke, not heart-related issues, that are the culprit. Luckily, when racers take their mark this weekend at the Proniño six-mile race in Madrid, they will only have to focus on battling each other, not so much high temperatures. That’s because Telefonica and French IT services group GFI Informatique have announced a new device that will be able to prevent heatstroke before it occurs.


The battery-powered gadget, which measures just 58mm x 30mm x 27mm, can be comfortably clipped onto a wrist and head band, or any part of a runner’s clothing for that matter. Still in its prototype stage, the wearable is based on an Arduino Pro Mini (ATmega328), and features a GPS module, a Lilypad temperature sensor and an M2M SIM card with global coverage. Additionally, it packs a LiPo battery with a life of about eight hours, which should be plenty for the duration of the event.

During the race, staff will use a special web-based app to monitor a runner’s position and body temperature, ensuring that the latter doesn’t exceed 104°F — one of the first signs of heatstroke. Meanwhile, the unit’s built-in GPS will provide accurate positioning of the wearer’s whereabouts throughout the course. The prototype will be connected to S.A.M.U.R. (Servicio de Asistencia Municipal de Urgencia y Rescate) should any emergencies arise.

Beyond spotting potential risks in marathons and other strenuous sporting activities, its creators say that the device can be used in outdoor work environments that entail high exposure to heat, as well as by the elderly and children — two segments of the population most likely to suffer from heatstroke.

Turn off this Arduino alarm clock by flipping it over

This DIY alarm clock even senses a user’s presence and saves power when they’re not around.

When it comes to Makers and their alarm clocks, we’ve seen some pretty nifty ideas in recent months. Added to that growing list is the latest project from Devdhar Patel with his clever take on the age-old timepiece.


Chronobot is a wireless analog clock that consists of a TFT screen, an RTC module for keeping time, a 3.3V battery and an Arduino Pro Mini (ATmega328) as its brains, all housed inside a custom 3D-printed case. An embedded sensor allows the device to sense its own orientation, providing users with the ability to turn the alarm on and off by merely flipping it. Impressively, the gadget even detects presence and powers down when no one is around.


“The alarm setting can be changed from the code. The colors can also be changed from the code, only they have to be in 16-bit format,” Patel reveals.

Is it time to make one of your own? Head over to its Instructables page here.

ShakeIt is an interactive light game

And the Makers gonna make, make, make, make, make. Baby, I’m just gonna shake, shake, shake, shake, shake!

When it comes to education, learning can be much more engaging with just a little bit of entertainment and gamification. Knowing this, Arkadi Rafalovich has developed an interactive art exhibit that is based on his earlier Smart Juggling Balls project along with a 3D-printed fixture embedded with several RGB LEDs. Dubbed ShakeIt, this Hackaday Prize entry is intended to demonstrate to kids how colors are mixed and then reward them with a fun-filled light game.


The system is comprised of three embedded balls and the light fixture. Each of the juggling spheres are equipped with an Arduino Pro Mini (ATmega328), a 6-DOF sensor, a few addressable LEDs and a LiPo battery. An external magnet activates a reed switch inside the balls and triggers them into action. As for ShakeIt’s light fixtures, these consist of an Arduino Nano (ATmega328), an NRF24L01+ with SMA antenna, a buck converter, 74 addressable LEDs, a Bluetooth module, along with some capacitors, a 3.3V regulator and a Diode 3A for reverse voltage protection.

The fixture connects to an accompanying smartphone app via Bluetooth, allowing it to be utilized as an interface and to adjust the various modes. A built-in accelerometer is tasked with measuring hard a ball is being shaken, while an NRF module handles the communication with the balls. Rafalovich also wrote some code for the system, which is designed to interact with up to 15 small balls at once, mixing up their colors and generating new hues. For this demonstration, however, only three were used.


The real fun starts when the interactive game mode is enabled, though. Rather than simply combining the light, the fixture generates patterns based on how strong the balls are shaken (hence the name of the project). First each kid is given a smart ball, each with a predefined color (red, green or blue). Once the sphere is jiggled, the light inside the ball becomes stronger. Each of the players then battle it out to see who can get their color to fill up the sphere completely until only one color remains. That person is declared the winner.

Not only does ShakeIt make for a great learning tool, it seems like it can be one heck of a party game. Want one of your own? Head over to its Hackaday.io page here to get started. Otherwise, watch the video below to see some grownups have a little fun.

Build an inexpensive handheld gaming console with ATmega328

If you love classic games like Tetris, you can now make an Arduino console to play them on the go and in full color.

If you’re looking for an extremely low-cost, minimalist gaming console that will take you back to a much blockier 8-bit era, you’re in luck. That’s because Maker Joao Vilaca has proven that you don’t need to browse eBay or head up into your parent’s attic to find an antique handheld controller, but instead can build one of your own for less than $20 in supplies.


Impressively, Vilaca required nothing more than a three-axis joystick, a small buzzer, a 2.2″ TFT screen, four AA batteries, and of course, an Arduino Pro Mini (ATmega328) in order to get his version of Tetris up and running.

The high-quality TFT screen featured an integrated ILI9341 controller, which he connected using Hardware SPI. Although the screen shipped as 240 x 320 pixels, Vilaca was able to make it a bit more gamer-friendly by configuring it into a 320 x 240 display. He even employed the help of Seeed Studios’ TFT library to simplify the interface.

Though he selected a Pro Mini for this project, the Maker notes that other ATmega328 based Arduino and Arduino-compatible boards can be used in its place. For those seeking a 5V chip like the Uno, Vilaca reminds us that you’ll need a level shifter from 5V to 3.3V to avoid frying the TFT.


And what would a video game be without its sound effects, most notably those old-school chiptunes? Cognizant of that, the Maker also implemented a small buzzer to provide audible feedback to the player. Cue the Tetris theme song!

Truth be told, this is not the first nor will it be the last Arduino gaming platform we stumble upon. However, we can’t help but love them all, whether it’s Nootropic Design’s Hackvision, Microduino’s Joypad or Kevin Bates’ latest iteration of Arduboy. Simplicity, nostalgia and Arduino, how can you go wrong? Want to create a handheld Arduino console of your own? You can find a detailed step-by-step breakdown of the project here.

Create your own muscle-controlled Wolverine claws

These DIY Wolverine claws will extend when you flex your muscles. 

While we’ve seen plenty of X-cellent DIY Wolverine projects in the past, this recent project from Advancer Technologies founder and die-hard Maker Brian Kaminski has surely topped the list of clawesomeness. He simply flexes his arms — and snikt! — the claws extend in a matter of seconds.


This project was devised as a way to celebrate the successful launch of the team’s fourth-generation muscle sensor, the MyoWare. For those who may not be familiar with the campaign currently live on Kickstarter, the wearable sensor platform is used to measure a muscle’s electric potential. The harder a wearer flexes, the more motor units are recruited to generate greater muscle force. The greater the number of motor units, the more the muscle electrical activity increases. MyoWare then analyzes this electrical activity and outputs an analog signal that represents how hard the muscle is being flexed. The harder it is flexed, the higher the MyoWare output voltage will go — as demonstrated in the latest Wolverine project.


To bring this claw to life, Kaminski attaches a few sensors to his arm and proceeds to making a muscle. As this occurs, MyoWare detects the flexing via EMG and converts it into a digital signal. This information is transmitted to an Arduino Pro Mini (ATmega328) embedded within the claw tasked with controlling the mechanism. Meanwhile, the Arduino’s built-in 5V regulator is also used to power the MyoWare.


An added bonus to the already X-tremely cool build is that a majority of its parts were 3D-printed. Intrigued? We thought you might be. Fortunately, Advancer Technologies has provided a step-by-step breakdown of its build over on MAKE: Magazine. However, those looking to get started may have to wait until MyoWare begins shipping in July.