Posts | Comments

Planet Arduino

Archive for the ‘MKR Zero’ Category

A popular goal among roboticists is animal-like locomotion. Animals move with a fluidity and grace that is very hard to replicate artificially. That goal has led to extremely complex robots that require a multitude of motors and sensors, along with heavy processing, to walk. But even those don’t quite match biological movement. Taking a new approach, engineers from Carnegie Mellon University and the University of Illinois Urbana-Champaign created a simple bipedal robot named “Mugatu” that walks using a single actuator.

This approach is counter-intuitive, but quite sensible when we actually look at the gaits of real animals. Bipedal animals, such as humans, don’t need to engage many muscles when walking on flat surfaces. We achieve that efficiency with balance and body geometry evolved for this purpose. In a sense, a walking human is always falling forward slightly and redirecting their inertia to take a step. This robot walks in a similar manner and only needs a motor to move one leg forward relative to the other.

The team built Mugatu using 3D-printed legs connected by a servo “hip” joint. An Arduino MKR Zero board controls that motor, moving it with the precise timing necessary to achieve the “continuous falling” gait. This prototype doesn’t utilize it yet, but there is also an IMU in the left leg that could provide useful feedback data in the future. For now, the robot relies on pre-programmed movements.

While the prototype Mugatu has little utility, the research could prove to be indispensable for developing more natural gaits with fewer actuators.

Image credit: J. Kyle et al.

The post Bipedal robot walks with a single motor appeared first on Arduino Blog.

For some students, getting decent grades or even finding the motivation to attempt to do schoolwork is a challenge, and this is often met with incentives such as money, praise, or simply avoiding embarrassment. Adam Soileau of element14 Presents had the idea to build a robot, which is an incentive unto itself by playing music, launching confetti, and waving one of those inflatable car dealership arm-waving tube things when grades cross a predetermined threshold.

The first challenge Soileau was met with involved determining the best way to launch confetti. Due to the prevalence of party poppers, or mini confetti cannons, he chose to use a high-torque servo motor that could pull the string back. The audio portion of the project relies on reading music data from an SD card, outputting it via a digital-to-analog converter (DAC), and then amplifying the sound using an LM386 op-amp for the speaker. Finally, the wacky waving inflatable tube-man is placed onto the fan in order to inflate it, while waving is done by toggling the fan on or off quickly with a MOSFET. An Arduino MKR Zero was employed to control each component due to its DAC and SD card capabilities.

Perhaps the most important aspect, retrieving grade data was done by harnessing Canvas’s web API through which assignment, quiz, and test grades can be programmatically accessed. Once collected, this data was then processed and stored in a CSV file so new grades could be compared to older ones. After an ‘A’ has been spotted, the system activates and rewards the student with the aforementioned confetti, music, and dancing. Detailed information about this project can be found here and seen in Soileau’s video below.

The post Celebrate good grades with this Arduino-powered robot appeared first on Arduino Blog.

Augmented reality (AR) is distinct from virtual reality (VR) in that it brings the real world into virtual gameplay. The most famous example of AR is Pokémon Go, which lets players find the pocket monsters throughout their own physical region. Minecraft is the best-selling video game of all time, but lacks any official AR gameplay. So Ryan Chan tackled the problem himself and built a system that translates real world movement into control of a player’s Minecraft avatar.

We’ll just assume that you know how Minecraft works, because you have probably played it yourself. Chan’s project works with the standard game and doesn’t require any special mods — Chan could even use this to play on others’ Minecraft servers if he chose. The system counts footsteps and converts them into forward movement in-game. It also detects real life rotational movement and replicates that movement in the game. But other actions, like attacking or swapping items, require conventional button presses.

The key components of this project are an Arduino MKR Zero board, a MPU-6050 IMU (inertial measurement unit), and two force sensitive resistors. The IMU detects rotational movement, while the force sensitive resistors detect footsteps when worn on the player’s shoes. Four mechanical key switches trigger the other actions. Chan configured the Arduino to appear as a standard USB HID keyboard and mouse when plugged into a computer, so Minecraft accepts the control commands without issue. To tidy everything up, Chan designed a custom PCB that hosts the aforementioned components.

Using this system for Minecraft gaming is tricky, as it requires plenty of real world open space to navigate the virtual world. But with access to a large park, it lets the player enjoy an AR Minecraft experience.

The post This project facilitates augmented reality Minecraft gaming appeared first on Arduino Blog.

As part of element14’s Build Inside the Box Challenge, James Lewis (AKA Bald Engineer) decided to make his own DIY tricoder from Star Trek. In the series, a tricoder is a ubiquitous scanning tool that can perform various scans of the environment through its onboard sensors, as well as record and analyze them later — all in a handheld format. Lewis’ design incorporates a MKR Zero as the microcontroller, a phototransistor to detect light levels, and an analog temperature sensor to sense ambient temperatures. 

The enclosure itself was based on a tricorder toy and recreated in Fusion 360. It features a hinge mechanism for easy opening and closing, as well as handling the wiring harness that connects both halves of the device. Once it was 3D-printed, Lewis moved onto the electronics.

A VL53L0X time of flight sensor was used to detect if the hinge was open, and thus if the OLED information screens should be turned on. Lewis utilized the SAM D21’s onboard capacitive touch controller to add four buttons onto his device for simple inputs. Finally, the DIY tricorder can play looped WAV files via its onboard SD card and DAC, along with an external op-amp and speaker circuit. 

To read more about how the Bald Engineer created this fun project and view its associated schematics, code, and design files, be sure to check out its write-up here on element14’s website. You can also see the build log and demonstration below! 

The post The Baldcorder is James Lewis’ tricorder-like device for measuring light levels and temperature appeared first on Arduino Blog.

As most homeowners with a basement will tell you, keeping track of the sump pump is an important part of maintenance, as neglecting it can lead to the basement turning into a swimming pool. This is the exact predicament that a recent element14 Build Inside the Box winner, Mike Moore, ran into with his house because freezing pipes and an unreliable pump often became problematic. He went with multiple approaches to solve this, including water level detection, temperature monitoring, and even checking if the pump has ceased working. 

The first component used was a TCST1103 photo interrupter, and its job is to send a signal if a bobbing piece of plastic gets between its emitter and receiver, which would indicate the water level has risen too high. For more granular and continuous measurements, Moore also implemented a VL53L0X time-of-flight sensor that sends a laser beam towards the water and waits for a reflection. Because water can distort this reading, a couple of readings get taken and then averaged together. Temperatures are read by a simple MCP9701 IC that was placed inside of a plastic tube and stuck to the side of the pit. Finally, detecting if the pump is running is handled by an MCP604 IC. 

All these sensors are controlled with an Arduino MKR Zero that can sound an alarm if something’s wrong, and power is provided via a portable high-capacity battery bank. In the future, Moore plans to add SD card logging so he can view long-term trends in the data readings.

To see more about his project, you can view the element14 Presents video below and check out Moore’s write-up here.

The post This MKR Zero system gives early warning of potential sump pump problems appeared first on Arduino Blog.

Within the Pokemon series there exists a special bicycle that plays a little tune when ridden, and this is what element14 Presents’ DJ Harrigan was trying to recreate with his DIY Pokebike project. It has a simple purpose: play a song and increase its volume while accelerating and then decrease the volume and eventually stop playing it once the bike comes to a halt.

The circuit uses an Arduino MKR Zero to handle all of the inputs and outputs, and with an onboard microSD card slot and the ability to output digital I2S audio, playing music is easy. Speed is determined by a Hall effect sensor and magnet pair that sends a pulse whenever the wheel has made a rotation. By tracking how many rotations have been made in a second and seeing the changes between these values, acceleration can be derived.

Harrigan then designed and 3D-printed a simple enclosure that houses all of the circuitry, including a battery pack. The front is shaped like a Pokeball, and it has an illuminated push button that allows for the user to interact with it. Finally, there’s a small speaker at the back connected to an I2S amplifier that takes signals from the MKR Zero and converts them into sound. 

With everything assembled and programmed, Harrigan had to make a slight modification as the wires coming from the hall effect sensor were unsightly, so he just made the pushbutton on the front toggle the sound on or off manually. Even though some adjustments were made, the project still turned out well, and you can read more about it on element14.

The post Turn your bicycle into a Pokebike with DJ Harrigan’s MKR Zero device appeared first on Arduino Blog.

Motion sensors for home security stick out like a sore thumb, as their shiny white exteriors can be easily seen from a distance. This is made worse when camping, as small, discrete security devices that blend into their surroundings are even harder to come by. This is what inspired Sean Miller to create his own that uses automotive bumper sensors to detect intruders and play loud noises when necessary. Better yet, the circuitry for this project was stuffed inside of an owl decoy, making it the perfect unassuming campsite guardian. 

At the heart of this disguised intruder detection system is an Arduino MKR Zero, which handles both the incoming distance readings from the sensors and playing various sounds from an onboard SD card. Miller had to perform a few hacks to get the automotive sensors working, as they use different custom protocols that can vary between manufacturers. After figuring it out, he then wired up the sensors to the MKR Zero and connected a small speaker to a custom amplifier circuit.  With the electronics completed, he produced some code that checks the distances between the owl and any obstacles, with an alert being produced if an intruder is detected nearby. 

You can read more about how Miller built this intruder-detecting owl here on Instructables, as well as see how he added an optional ESP8266 for sending alerts to his phone. 

The post This disguised campsite security system lets you know ‘hoos’ there appeared first on Arduino Blog.

How much coffee do you consume in a day? No idea? Then the Nespresso Shield by Steadman Thompson may be just what you need!

The device employs an Arduino MKR Zero, and a microphone unit to sense when a Nespresso machine gets louder than a certain threshold. When this level is met, it knows that a drink is being prepared and records this on the board’s built-in SD card reader. Info is coordinated with RTC values, allowing the card to be pulled in order to produce nice graphs in Excel or LibreCalc.

It also keeps track of water levels, based on how many cups have been poured, with a reset button and LED as the user interface. The unit simply sits on top of the machine, so there’s no modification needed whatsoever. 

The post The Nespresso Shield logs your coffee consumption using a MKR Zero appeared first on Arduino Blog.

While some keyboards provide media keys or even knobs to adjust your overall computer sound up and down, often what you really want is the ability to tune program volumes separately. To make this extremely easy, SNR Tech Bytes has come up with a beautifully-designed controller, which runs on the MKR ZERO.

The device features five encoders to individually tune the master volume, Discord, Chrome, gaming, and Spotify, with the help of software on the PC itself. Encoder button mutes each channel as needed, using NeoPixels below to indicate each status.

The build is based on the deej volume mixer, and more specifics on this version are available on GitHub.

While 2020 may seem like a very futuristic year, we still don’t have robotic maids like the Jetsons’ Rosie the Robot. For his latest element14 Presents project, DJ Harrigan decided to create such a bot as a sort of animatronic character, using an ESP8266 board for interface and overall control, and a MKR ZERO to play stored audio effects.

The device features a moveable head, arms and eyes, and even has a very clever single-servo gear setup to open and close its mouth.

UI is via smartphone running a Blynk app, and Rosie’s antennas can light up along with a “beep beep” sound to let you know it needs your attention!

More details can be found in Harrigan’s post here.



  • Newsletter

    Sign up for the PlanetArduino Newsletter, which delivers the most popular articles via e-mail to your inbox every week. Just fill in the information below and submit.

  • Like Us on Facebook