Hanging Wall Plotter by HomoFaciens

“V plotter” / Hanging Wall Plotter by Norbert “HomoFaciens” Heinz

I’m very late to the party noticing the stripped down, simplified, and well documented hanging wall plotter by Norbert “HomoFaciens” Heinz posted by Liz Upton back in 2015! Norbert’s blog post provides lots of photos and details, while his videos more information with additional nuance.

One of the things I love about this style of drawing robot is that all the materials and hardware are fairly inexpensive, much of it can be built out of materials people already have or could salvage, almost any part can be over-engineered or streamlined, and the results are almost disproportionately amazing.

Great project Norbert!

Mirobot by Ben Pirt

Mirobot, ready for drawing!

Mirobot, ready for drawing!

A few weeks ago I stumbled across the Mirobot website after seeing a post on the Arduino forums.  The creator, Ben Pirt, designed this cool open source drawing robot that is driven over WiFi to roll around and draw.  One of the nifty things about this project is that the robot is that it has an almost unlimited drawing size.1

Ben was kind enough to answer a few questions about his project:

  • What is the Mirobot?
    • Mirobot is a simple drawing robot that’s designed to help children learn about programming and technology. It’s all open hardware and software so once you’ve done some of the basic exercises and you’ve built up your confidence you can start hacking it to do different things. It’s battery powered and WiFi-enabled which means you can put it on your home network and just start using it from any web enabled device.
  • How did you get started in robotics?
    • This is my first robot really! Although I guess back in the 80’s was when I first got my hands on a robot when I used the BBC Turtle. I was lucky because my Dad was a teacher and was involved int he early days of computers in schools – I was his willing guinea pig. Every school holiday he would bring something home to play around with and the Turtle was always one of the most popular things.
  • Why did you decide to work on a drawing robot? Where there any other robots that inspired you?
    • A couple of years ago I took my kids to the Science Museum in London (worth a visit if you ever get a chance) and saw one of the original Turtles that I’d used in my childhood. After being immersed in technology for a while now it struck me that what was then a very expensive and complex machine could now be constructed relatively easily and at low cost. In the era of the original Turtles you were lucky if you had one per school, but with an open hardware approach and using open platforms like the Arduino, much of the development is already done. I’m now able to build a robot that improves on the original (it has batteries, uses WiFi) at a fraction of the cost.
    • But the real reason I decided to start work on the project was so that I could build it with my kids. We built the first release over Christmas and it’s evolved from the learning that gave me.
  • Who do you see using these robots? What do you hope they’ll learn as they build and program the robot?
    • It’s designed with children in mind – it’s been made easy to assemble and I’ve put a lot of time into making sure the PCB is easy to solder. I’m hoping to work with schools so that a class can all build their own robots and then start learning by using them. When you build the robot yourself you have a much greater appreciation of where it came from. As you put together the PCB I take the opportunity to explain what each piece is doing so even if you don’t fully understand how it works, you still get more of an understanding about what it’s doing. You also get more of a mechanical understanding about how things fit together because nothing is hidden and you can see what everything is doing. Once you start using it you can obviously develop your understanding of some basic programming, but once you’ve mastered this there are lots of other ways you can learn by modifying it;
      • – you can customise the web application and learn Javascript / HTML
      • – you can program it from Javascript, either in-browser or via Node.js
      • – you can modify the firmware and add functionality to the robot
      • – you can add sensors to develop what it’s capable of
  • How big a drawing is the robot capable of? How complex a drawing?
    • Well the robot is battery powered and wireless so the question is how big is your piece of paper? I do have some plans to make a massive drawing at some time!
  • Besides drawing what else could people do with this robot? Do you think there are any commercial or industrial applications?
    • I definitely see Mirobot as a base for future experimentation so I can see people adding sensors and making it autonomous. Maybe someone will use it as a base to make the cleaning robots like in the Fifth Element! I’ve intentionally brought out any unused pins on the Arduino to a header so that it’s easy to add hardware.
  • Why did you choose to go with a custom designed board rather than an Arduino with a motor shield? What other applications do you see for the Mirobot board?
    • I originally started with a shield for a regular Arduino but found that it turned out to be quite expensive (and one of the goals of the project is to make it as low cost as possible) and also quite bulky. It began to impact on the physical design of the chassis and was quite difficult to mount (it required screws, and these cost money and add to the complexity of the construction process). I also wanted people to be able to completely build their own robot so liked the idea that you really do build everything. By building a custom board I can make it fit perfectly into the design of the robot.
  • Why did you choose open source?
    • I’m a big believer in the Open Source approach and I think this is the perfect project for it. If the aim of this project is to get it into as many children’s hands as possible then allowing anyone to make it, and also to learn from the making process, is a key part of that.
  • What’s your favorite thing to draw with the Mirobot?
    • At the moment my favourite test pattern is the classic 5 pointed star which can be nicely drawn in LOGO by doing:
      • repeat 5 [
      • forward 100
      • right 144
      • ]
    • Although I’m still learning! I’d like to teach it to do some portraits by converting vector images to drawing commands.

Thank you to Ben for taking the time to share more about his project!

Mirobot - drawing!

Mirobot – drawing!

  1. As long as the paper, pen, and batteries hold out! []

Maker Artist Ytai Ben-Tsvi and his IOIO Board Plotter

Ytai showing off his plotter art at Codame 2013

Ytai showing off his plotter art at Codame 2013

Easily one of the most memorable aspects of exhibiting at this year’s Maker Faire Bay Area was getting to meet and interact with lots of other Makers.  Ytai Ben-Tsvi had built and brought a pen plotter of his own design – and it was amazing.

Ytai’s pen plotter used an Android tablet, his IOIO OTG board1 , two stepper motors, two comically large spools, and lots of custom code to turn pictures taken with the tablet into instant portraits on the fly.

His plotter was everything a Maker Faire exhibit should be – highlighting the intersection of art and technology while inviting the audience to be a part of the action.  Can you believe this guy was reluctant to call himself an artist?

After Ytai was invited to participate in the Codame 2013 art-tech festival2 he decided to create an entirely new drawing algorithm to turn images into a single line drawing which appears to be sharp scribbles up close and a detailed image from a few meters away.

Photo transformations with Ytai's ScribblerDemo

Photo transformations with Ytai’s ScribblerDemo

What I love about Ytai’s drawing process is that it produces a drawing with a sense of whimsy and movement without the hard number crunching necessitated by a Traveling Salesman Problem3 style drawing.4  By allowing the algorithm to have lines cross over one another, something the TSP method eschews with its own aesthetic, Ytai’s drawings essentially gets “for free” extra dark patches where lines closely intersect.5

Looking at this drawing, it seems to me that an SVG created from his algorithm conveys so much more meaning with far less points than a TSP file.  At least for my own PlotterBot, far fewer points would also mean a much faster, and more satisfying to watch, drawing.  I would estimate that in the time it took Ytai to cover a wall, I might have been able to create one, perhaps one and a half, drawings.  And, as any good Maker does, Ytai has shared the fruits of his hard work in the form of the source code on Github.

  1. Ytai’s succinct description of the IOIO board says it all, “The IOIO-OTG is a printed circuit board for electronics hobbyists and prototypers, which addresses a very common problem: how do I use my {computer, tablet, phone} to control my {robot, dish-washer, cat-feeder, etc.}.” []
  2. An art-tech festival?!  Why the hell aren’t there more of these things?! []
  3. Link to blog post showing a method []
  4. Doesn’t exactly hurt to have a cute kid as a subject either []
  5. Having played with TSP drawings a lot, I have discovered that finding the right balance between lightness versus darkness and simplicity versus complexity and quick versus glacial to be… maddening.  Like H.P. Lovecraft maddening []