I was pleased to be selected to be a part of the Intel Edison IoT invitational here on Instructables (please consider voting if you like it!).The project that I proposed was an automated "light painter" which would use stepper motors to move an RGB LED around in space by winding the strings it was suspended from up and down.

The Edison made things interesting, since it allowed me to handle things at a higher level (I was able to do most of the project's code in Python) as well as providing useful features like WiFi.

The repeatability of an automated light painter allows for some interesting options, such as animation:

System Overview

The RGB led is suspended from two strings, the other end of each is wrapped around a pulley on a stepper motor. By Shortening or Lengthening the strings, the LED can be positioned at any X,Y coordinate between the two motors.

The stepper motors themselves are each driven by a Grove I2C motor driver. The motor drivers receive commands from the Edison via the I2C protocol.

The colour of the RGB LED is controlled by an ESP8266 WiFi module, which receives commands from the Edison (or can be controlled manually by a laptop of cellphone). The LED and ESP8266 are powered by a battery, so they have the associated voltage regulation circuitry as well.

The software that handles the coordinate geometry as well as the stepper control, LED control and SVG importing is all written in the Python programming language and runs on the Edison itself.

Here you can see the "light pen" hanging in place, suspended from the two pulleys

And here is the result of moving it around while the camera takes a long exposure photo.

Prior Art

String plotters are by no means a new idea, but this one is the first I have seen with wireless control of an RGB LED over WiFi and driven by Python.

This guy has made one that works on a XY gantry, but it's "art", so if that's your jam you can read my Instructable with some arty bollocks in mind.

And this chap has done one with string like me, but only in one colour,

Why you should read

Learn how to

  • Use Python to control the Intel Edison
  • Drive Stepper motors
  • Upload New firmware to Grove I2C Motor Drivers
  • Convert SVG to XY line segments
  • Control an ESP8266 with an Intel Edison

Even if you have no desire to build a string plotter, I hope that you will find something useful in here. I have tried to describe each module in a useful way, so that the concepts can be applied to other things too. One last thing. if you like my project, please consider voting for me in the contest, thanks!

Step 1: Parts Used

Here is a list of all the parts that I used.

For the Mechanics

  • 2x Stepper Motors (salvaged from printers: read motor section for details)
  • Nylon Fishing Line
  • Wood (or anything else to mount the motors to)
  • 2x 3mm Prop Adaptors (to attach pulleys to 3mm motor shafts)

For the Controller

For the Wirelessly Controlled Light

  • 1x ESP8266 Wifi Module
  • 1x RGB LED
  • 1x 3.3V Switchmode Regulator
  • 1x 5V Switchmode Regulator
  • 1x 3.3V FTDI Programmer

For the Camera


  • Resistors
  • Wires
  • Proto-board
  • Solder
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<p>Light Painting with an Edison. *Mindblown*</p><p>Fantastic Instructable. Congrats with the win.</p>
Thanks! This Intel challenge and its prizes were great incentive to get it working nicely, so I was very happy to end up winning something!
<p>I really like the detail you put into your instructables. Great work!</p>
<p>This is such a unique twist on a classic plotter, you did an amazing job!</p>
Thank you :-) It was nice to have the Intel Invitational motivating me to complete something i have had in the back of my mind for ages.
It's awesome.. voted :)
<p>Thank you very much!</p>

About This Instructable




Bio: Electrical Engineer by trade, tinkerer by heart.
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