Monthly Archives: October 2019

Every jack-o’-lantern needs a pair of animatronic eyes

via Arduino Blog

If you’d like your jack-o’-lantern to stand out, a pair of animatronic eyes should do the trick. While there are numerous ways that you can go about this, few (if any) look as good as the set made by Will Cogley in the first video below.

The incredibly realistic 3D-printed eyeballs are installed into the hollowed out pumpkin using skewers as supports, and glance in all directions, along with orange eyelids that open and close for an even more human(ish) appearance. 

The second clip delves deeper into the eyeballs themselves, which come in several forms. Control is via a Wii Nunchuk-esque joystick interface, with the help of an Arduino.

Enginursday: Building a Wireless EL Wire Dance Suit, Part 3

via SparkFun: Commerce Blog

As with any project, you will want to start small and work on the project in parts. In this case, my initial goal was to built one suit for Mark IV before making six more for each student. This has been an ambitious goal of mine since making the first version for my students back in 2014.

Mark 1: EL Dance Shirts on Bboys and BGirls

Once I created the EL suits for each student, I decided to move forward to the next goal and control two channels wirelessly. Satisfied with a wireless blink test on a breadboard between a controller and one sequencer, I tested the setup remotely with a wireless glove and three sequencers. After a few successful tests, off I went to modify the EL Sequencers, hacking the EL inverters, making custom EL wire extension cables, cutting out enclosures, and connecting the hardware for each dancer. This was tedious but not as time consuming as sewing the EL wire along each suit's arms and legs. I had enough time so I decided to go the extra mile to sequence the suits to the beat of the music three times in the piece.

Cardboard Enclosure with Electronics Cardboard Enclosure Closed

How did the performance go? Overall, it went well. However, I found it difficult to dance and control the suits simultaneously. One of the sections that I decided to sync the animation with had a lot going on. The music was fast music and there was lot of movement. This was not ideal as the controller had to be in the correct mode before I was able to hit the send button. What I could have done differently with this setup would have been to not to have as much movement when hitting the send button.

Mark IV: EL Wire Dance Suit on BBoys and BGirls

Mark IV: EL Wire Dance Suit in 2017

How Do You Build Such a Thing? Part 3

Check out the tutorial below for details on how to complete this project.


Wireless Controlled Wearable EL Wire Dance Suit

October 31, 2019

In this tutorial, we will build an EL wire dance suit that can be controlled by a wireless glove controller!

Have you built an EL Wire Suit before? If you have, did you use an XBee or a different wireless module? Let us know your thoughts below in the comments. Otherwise, tune in some time in the future for Mark V for some additional upgrades and improvements! ;D

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Build the ultimate 4K home theatre PC using a Raspberry Pi 4 and Kodi

via Raspberry Pi

We love Raspberry Pi for how it’s helping a new generation of children learn to code, how it’s resulted in an explosion of new makers of all ages, and how it’s really easy to turn any TV into a smart TV.

While we always have a few Raspberry Pi computers at hand for making robots and cooking gadgets, or just simply coding a Scratch game, there’s always at least one in the house powering a TV. With the release of the super-powered Raspberry Pi 4, it’s time to fully upgrade our media centre to become a 4K-playing powerhouse.

We asked Wes Archer to take us through setting one up. Grab a Raspberry Pi 4 and a micro-HDMI cable, and let’s get started.

Get the right hardware

Only Raspberry Pi 4 can output at 4K, so it’s important to remember this when deciding on which Raspberry Pi to choose.

Raspberry Pi has been a perfect choice for a home media centre ever since it was released in 2012, due to it being inexpensive and supported by an active community. Now that 4K content is fast becoming the new standard for digital media, the demand for devices that support 4K streaming is growing, and fortunately, Raspberry Pi 4 can handle this with ease! There are three versions of Raspberry Pi 4, differentiated by the amount of RAM they have: 1GB, 2GB, or 4GB. So, which one should you go for? In our tests, all versions worked just fine, so go with the one you can afford.

Raspberry Pi Cases

Flirc Raspberry Pi 4 case

Made of aluminium and designed to be its own heatsink, the Flirc case for Raspberry Pi 4 is a perfect choice and looks great as part of any home media entertainment setup. This will look at home in any home entertainment system.

Official Raspberry Pi 4 case (in black and grey)

The official Raspberry Pi 4 case is always a good choice, especially the black and grey edition as it blends in well within any home entertainment setup. If you’re feeling adventurous, you can also hack the case to hold a small fan for extra cooling.

Aluminium Heatsink Case for Raspberry Pi 4

Another case made of aluminium, this is effectively a giant heatsink that helps keep your Raspberry Pi 4 cool when in use. It has a choice of three colours – black, gold, and gunmetal grey – so is a great option if you want something a little different.

Optional Raspberry Pi add-ons

Maxtor 2TB external USB 3.0 HDD

4K content can be quite large and your storage will run out quickly if you have a large collection. Having an external hard drive connected directly to your Raspberry Pi using the faster USB 3.0 connection will be extremely handy and avoids any streaming lag.

Raspberry Pi Fan SHIM

The extra power Raspberry Pi 4 brings means things can get quite hot, especially when decoding 4K media files, so having a fan can really help keep things cool. Pimoroni’s Fan SHIM is ideal due to its size and noise (no loud buzzing here). There is a Python script available, but it also “just works” with the power supplied by Raspberry Pi’s GPIO pins.

Raspberry Pi TV HAT

If you are feeling adventurous, you can add a Raspberry Pi TV HAT to your 4K media centre to enable the DVR feature in Kodi to watch live TV. You may want to connect your main aerial for the best reception. This will add a perfect finishing touch to your 4K media centre.

Rii i8+ Mini Wireless Keyboard

If your TV does not support HDMI-CEC, allowing you to use your TV remote to control Kodi, then this nifty wireless keyboard is extremely helpful. Plug the USB dongle into your Raspberry Pi, turn on the keyboard, and that’s it. You now have a mini keyboard and mouse to navigate with.

Read more for free…

Looking to read the rest of this article? We don’t blame you. Build the ultimate 4K home theatre PC using a Raspberry Pi 4 and Kodi is this month’s feature article for the brand-new MagPi magazine issue 87, out today.

You can read issue 87 today, for free, right now, by visiting The MagPi website.

You can also purchase issue 87 from the Raspberry Pi Press website with free worldwide delivery, from the Raspberry Pi Store, Cambridge, and from newsagents and supermarkets across the UK.

The post Build the ultimate 4K home theatre PC using a Raspberry Pi 4 and Kodi appeared first on Raspberry Pi.

Pen plotter? Laser engraver? This DIY machine gives you both!

via Arduino Blog

If you find yourself debating between a pen plotter or laser engraver, this project by Patrick Panikulam lets you have the best of both worlds in style. The DIY device pulls a writing instrument in the X-axis using a belt-driven overhead system, while the base itself moves in the Y direction.

Motion is handled by an Arduino Uno, along with a CNC shield and two A4988 drivers that actuate modified 28BYJ-48 steppers. The shield also outputs laser control signals, which are converted into PWM signals for the lifting servo when in pen mode. 

It’s an extremely clean build, and even features a Bluetooth module for wireless communication with your computer. Panikulam provides more details here if you’d like to create your own!

A couple of months back while checking out a few laser engravers on aliexpress, I came across some USB powered laser engravers. It was awesome that these could engrave on a variety of materials and also cut out shapes and designs from sticker sheets and paper and doing all this powered by a 5V USB supply. But the downside of these engravers was that they had a small work area, in most cases just 40mm X 40mm which is definitely way too small for my needs.

So I thought why not design and 3D print my own laser engraver from scratch. I started the designing process in Fusion 360 while keeping in mind all the 3D printing tolerances. And finally came up with something really cool. Along the way, I decided to make the laser holder modular so that I can easily replace the laser with a pen or marker for pen plotting. I also added a Bluetooth connectivity feature so that wired connection between your PC and the engraver can be eliminated while transmitting G-codes.

A Disaster and a Half

via SparkFun: Commerce Blog

Every autumn deserves its pumpkin hacking projects. This Halloween, our pumpkin comes with a horror story. It began last year in early November. All the Halloween decorations were on clearance, and I found a plastic jack-o-lantern bucket for 15 cents. On first sight, I knew I must remote control it. Over the months following, the project came to my work bench now and then. I did simple things like cutting holes for the wheels, and mounted some of the mechanical things. Cutting the plastic with a utility knife was super easy.

Around the end of September this year, I sifted through my scavenged collection of electronics and formulated a plan. I decided on some Bluetooth devices because I wanted to explore that technology. The particular board in my stockpile was discarded from the product development process (insert eerie sound effects here). I didn't know its history. I didn't know if it had the standard released bootloader. I didn't even know if it worked. I was driven to make this pumpkin roll, so I chose to go forward with it. Our SparkFun nRF52832 breakout board would provide the brains and radio for the operation. The new Qwiic Motor Driver would control the drivetrain. Last, a SparkFun USB LiPoly Charger would provide battery management for the whole system.

SparkFun nRF52832 Breakout

SparkFun nRF52832 Breakout

Qwiic Cable - 100mm

Qwiic Cable - 100mm

SparkFun Qwiic Motor Driver

SparkFun Qwiic Motor Driver

SparkFun USB LiPoly Charger - Single Cell

SparkFun USB LiPoly Charger - Single Cell

SparkFun Qwiic Adapter

SparkFun Qwiic Adapter

Dual Motor GearBox

Dual Motor GearBox


Toy Tires - Off Road


Confident in my success, I walked over to marketing and asked to write a blog about this project ( tense orchestra music), and we set the blog date near Halloween. It was only some wiring and software development – what could go wrong?

Drama and jokes aside, I’m bummed I don’t have a pumpkin to show today. My job here is IT, not EE, so this is my free time hobby. I have a number of other things that consume that free time, such as my two young children. Here are the high-level things that went wrong with the pumpkin.



My first holdup was getting any code to upload to the Nordic board. I recently started using PlatformIO and it’s awesome. It has the features of Visual Studio Code (or Atom) and a huge number of board and library definitions built in. The SparkFun nRF52832 breakout board is not explicitly in the list of supported boards. If I understand this GitHub issue, a breakout board is close enough to a bare chip to not merit its own named board definition.

That hindered my progress in my first-choice IDE. I’m certain I could get it to work with enough time, but I was already so close to my deadline so I chose to try something else.

Segger Embedded Studio

My second choice was to follow Nordic Semiconductor’s recommendation: Segger Embedded Studio with the Nordic SDK. SES is focused on ARM chipsets, and has a workflow that resembles Visual Studio. Nordic has built their SDK to integrate into SES. This combo provides the best capability for working with Nordic SOCs on OS X. I spent a couple hours following the instructions, trying to troubleshoot why SES didn’t find the SDK. I’ve set up IDEs with SDKs before, and I know issues such as this can take a huge amount of time to fix. I stopped there. The IDE looks like it’s great for ARM development, so I look forward to getting back in there another time.


I fell back on the old familiar. SparkFun has a board definition for our nRF52832 breakout board in Arduino, so that situation got me out of my standstill. On to software development!


Bluetooth is a large topic; I didn’t know quite how large until I dove in. The process of developing firmware would take longer than expected. A Bluetooth network must have a central node and the rest are peripheral nodes. Each node specifies what it can do in one or more profiles. A profile can have multiple services. Each service can have multiple characteristics. A characteristic has a value (usually shown in hex) with one or more permissions assigned to it. Each of those pieces has a UUID associated to keep them all straight. There are standard profiles with reserved UUIDs for things like mouse, keyboard and audio devices.

The task of inventing the Pumpkin Control Profile didn’t pan out as I hoped. I also tried to find a profile to use with a ready-made phone app (more on that below). I resorted to a UART profile I found in the examples of the BLEPeripheral library.

The BLEPeripheral library does a great job making some of all that complexity more accessible. It even forced me to learn how to spell peripheral. However, it does not enable the user to create a central node. I’m bound to using a phone or computer to act as my central node until I can determine how to get center functionality in an ARM chip.

iOS Apps

I tried two iOS apps with joysticks for Bluetooth. Each of them required some specific hardware. I assume they’re looking for the UUIDs or device names of the product they support, and I tried to get information I needed to fake them out. Maybe the info is out there, or I’m overthinking it. Either way, the joystick on the phone didn’t happen. Nordic has some awesome mobile apps for their products. The nRF Toolbox app, among other functions, has a UART feature with assignable buttons. I gave each button a couple of ASCII characters that correspond to instructions for the two motors in the pumpkin firmware.


Poorly planned connector placement

Disconnectable assemblies are my favorite. Whenever possible, my projects have pin headers and other connectors wherever the solder joints occur. This makes it possible to untangle the spaghetti.

The buttons for this board are smallish, and they are necessary to put the device in DFU mode. That is not a huge problem, but I chose to put all of the connections to the board on the same side as the buttons - not good. There is now a tiny fence around it, and my finger barely fits inside. Uploading to the pumpkin meant I had to find the button by touch and hold it while plugging in the FTDI cable. I spent most of my time developing on another of the same board with no such impediments.


The I2C didn’t seem to work for me at the start. After plenty of trial and error, I noticed a highly valuable comment from Bobby on our tutorial page. Basically, you have to define in Arduino the SDA and SCL pins you want to use. After a couple of hours, I thought I was finally ready, and no - the devices didn’t connect. I tested the motor driver with RedBoard and Qwiic shield, so I know it works. This is the final problem. I’d have a drivable pumpkin if I could get them to talk. It’s fixable, but not in time for this blog post.

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Defeat vs Failure

If you’ve made it this far into the horror story, you’ve reached the unresolved ending. Will the pumpkin make it out alive? Will the gremlins kill it? It’s also the most important part of this story. I love a podcast called Making It. It’s three YouTubers that converse about making physical things for content on their channel. One of the recurring themes in the podcast is how to deal with not succeeding. When you make a thing, it may not turn out as expected. That’s the situation I’m in, so I get this following bit of inspiration from the podcast.

As of this writing, I’m defeated. The pumpkin doesn’t work, but to quote Thomas Eddison:

I have not failed, I have just found ten thousand ways that won’t make a remote control pumpkin.

If I stop now, I will fail. However, I’m going to get this pumpkin rolling. Since the problem is the I2C connection, I can either fix it or replace it with a simpler motor driver. I’m also keeping a positive attitude about all the external things I used in this project. I won’t blame the IDE or the manufacturers when it was clearly my preparation and decisions that led me here.

I may be defeated at the time of this post, but I won’t fail. Watch the comments for updates on this pumpkin. While you’re down there, misery loves company. I’d love to hear your horror stories too.

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Project anyone’s face onto your own with Raspberry Pi Zero

via Raspberry Pi

Sean Hodgins is back with a new Halloween-themed project, this time using a pico projector and a Raspberry Pi Zero to display images and animations onto a mask.

It’s kinda creepy but very, very cool.

Face Changing Projection Mask – Be Anyone

Have a hard time deciding what to be on Halloween? Just be everything. Some links for the project below. Support my Free Open Source Projects by becoming joining the Patreon!

Face-changing projection mask

Sean designed his own PCB – classic Sean – to connect the header pins of a Raspberry Pi Zero to a pico projector. He used Photoshop to modify video and image files in order to correct the angle of projection onto the mask.

He then 3D-printed this low poly mask from Thingiverse, adapting the design to allow him to attach it to a welding mask headband he purchased online.

As Sean explains in the video, there are a lot of great ways you can use the mask. Our favourite suggestion is using a camera to take a photo of someone and project their own face back at them. This idea is reminiscent of the As We Are project in Columbus, Ohio, where visitors sit inside a 14-foot tall head as their face is displayed on screens covering the outside.

For more of Sean’s excellent Raspberry Pi projects, check out his YouTube channel, and be sure to show him some love by clicking the ol’ subscribe button.

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