Sunday, February 5, 2017

LogoTurtle Knows the Alphabet

I was inspired by Erik Nauman's student's project to program the LogoTurtle to draw the alphabet. I mused in a reply tweet that one could program each letter in a single document then call the letters in the startup procedure to spell words. And thus began a great Logo programming challenge.

I drew the first four letters on a piece of graph paper to determine the overall size of each letter. The letters occupied a 10 x 10 grid that I translated to a 100 x 100 grid on the LogoTurtle. Also, each letter was programmed so the LogoTurtle returned to where it started. This way I could program a kerning procedure to move the LogoTurtle into place to draw the next letter in a word.

I programmed about four letters an evening, refining the angles and degrees so it could write with relative precision when I finished.

I wrote my son's name with the first complete alphabet procedure.

You can download the alphabet text file and use it with your LogoTurtle. It is an interesting addition to the LogoTurtle's capabilities. It was also a fun experience to design a "font," though I claim no proficiency at this art form!

Friday, February 3, 2017

PIX-E Gif Camera

The "GIF-MAKING CAMERA" announcement on the cover of Make: volume 55 immediately caught my eye, and the easy-to follow directions convinced me that it would be a great project to cut my teeth on the Raspberry Pi, specifically the tiny Pi Zero.

While I waited for the hardware to be delivered I 3D printed the housing on my Replicator in blue and translucent red ABS. The parts were refined and very well designed and printed beautifully.

I used these helpful directions to set up the Raspberry Pi Zero to run headlessly after connecting it to my router with a USB to ethernet dongle. It helped immensely that I run Linux on my daily laptop and knew my way around the command line and filesystem. It was surprisingly easy to get the Pi Zero up and running with the required packages. The small form factor and zippy Linux distribution really intrigued me: I can foresee using this device more often.

While the article included a circuit diagram, I found a Pi Zero pinout to be very helpful since I soldered the PowerBoost directly to the Pi Zero and needed to know to which of the GPIO pins I needed to connect.

The camera, Pi Zero, and battery fit beautifully inside the housing (again, the design refinement was evident); the battery even snapped into the housing!

I added to the project by designing a lanyard bracket that can be attached with two 16mm M2 machine screws: since the camera is bulky, it's nice to be able to hang it from my wrist when not taking photos.

The Python script that makes the magic happen takes six photos fifteen milliseconds apart, hands them off to imagemagick, and churns out a gif. Sometimes imagemagick does not properly process the images and creates 0K gifs, but that is kind of like the disposable film camera that inspired this project.

The oversize power button, while awesome looking, tends to get flipped when I stuff the camera in my bag. I have resorted to taping it in the off position.

Here are a few of my photos.

I would highly recommend this project for anyone interested in photography, 3D printing and the Raspberry Pi. The Python script can be customized and changed, the housing is a fun 3D print, and the results are whimsical!

Saturday, January 28, 2017

Bringing Logo to NEIT17

I was privileged to attend the New York Association of Independent Schools NEIT17 Unconference at the Mohon Mountain House where I facilitated an open session on Bits to Atoms: Logo and Fabrication for a group of teachers. We had enough time for them to play with Turtle Blocks, and Maureen even built a piece of jewelry!

Several people were able to work through the workflow and were excited to bring the project back to their schools. One person planned to adapt the workflow to the work she and her students do in MicroWorlds by using online-convert to create an svg from the graphic file they produce in MicroWorlds. 

I also gave an ignite talk about the LogoTurtle.

Judith Seidel also spoke in part about her long relationship with Logo in the classroom and shared images of many of her favorite projects.

It was exciting to get people thinking about Logo and to showcase some projects, new and classic, that are very usable in today's classroom.

Friday, January 27, 2017

MacPaint Dot Matrix Art: Circuitboard01-03

Circuitboard01-03, 2016-17.

This is a piece I thought about for a while, worked on and didn't finish, then suddenly finished this afternoon.
I drew it in MacPaint on a Mac 512K using Brush Mirrors. I was given a Mac 512K and an ImageWriter I with two bags of ribbons in various colors. Evidently, kept properly packaged, they resist drying out.

I printed successive parts of the drawing in different color inks on the dot matrix printer. I rolled the tractor feed paper back into position as closely as I could to print over the same areas multiple times.

These photos are details of the piece, where you can see the impact from the print head. 

I really love this process; it is akin to multiple runs through a printing press from 1984.

Saturday, January 21, 2017

3D Printed Fisher Price "Records"

During my time as the Creator of Learning and Discovery Experiences one project I worked on was 3D printed records for the vintage Fisher Price phonograph. The vintage version of the phonograph operates like a music box, with the "stylus" consisting of many tines that are plucked by the notches in the record grooves. 

There is an excellent Instructable that walks you through the technical process of fabricating your own records using custom software. The program where you create the music that the record contains is a Windows executable. I run it in Wine on my Linux laptop; the sound does not work in Wine on my machine, unfortunately, but that does not stop me.

My latest records are a copy of part of "Stairway to Heaven," which is included along with the software. Additionally, I created another Moondog record, this time of part of his "Elf Dance." His music lends itself to a music box, in my opinion.
I would enjoy the opportunity to 3D print a record with a resin or powder-based printer. Milling a record would also be a fun opportunity. This is a fun project, especially if you take the opportunity to compose your own music for a custom record. Give it a try and share your work!

Saturday, January 7, 2017

LogoTurtle Bump Sensor

I designed a bump sensor bracket for the LogoTurtle that you can 3D print and add to your LogoTurtle. The model was designed for the laser cut version of the chassis. However, with longer battery holder screws it could easily be attached to the 3D printed chassis as well.

The bump sensor is built around a small rocker switch.

I soldered two wires to the switch and soldered the wires to the LogoTurtle board. The ground connects to pin A2 on the Metro Mini through a 10K resistor. The positive wire from the switch connects to the positive rail on the LogoTurtle board.

The switch sits behind a tongue depressor that has two one inch springs behind it. The switch activates if the bumper is pressed nearly everywhere along its length. The sensitivity of the switch can be configured by moving the rocker switch closer (or farther) from the bumper.

A simple Logo procedure can be uploaded to the LogoTurtle to have the turtle drive until the switch is activated. This example backs up 200 then turns somewhere between 10 and 360 degrees before going forward again. This procedure could be made more "sensitive" by having the LogoTurtle drive a shorter distance before it polls the switch data.
to startup

to bump
ifelse a2 > 1000
[bk 200 rt random 10 360]
[fd 100]
This addition to the LogoTurtle adds functionality to this robot: in addition to making beautiful art, the LogoTurtle now can be programmed to behave as a roaming, autonomous robot capable of navigating flat terrain with obstacles. 

3D print yourself a bracket and upgrade the functionality of your LogoTurtle!

Tortoise and Hare Automaton

Over winter break from work I built a "Tortoise and Hare" automaton, based on the nursery tale. I used some of my 3D printed automaton parts that I used in my "The Cow Jumped Over the Moon" automaton, refining them slightly.

Again, the automaton was housed in an upcycled cigar box. These boxes are well made, inexpensive, and are the perfect size for a small, hand-held automaton.

This automaton used an oblong cam, a round cam, a round cam follower, and a pivot to produce two different movements from the hand-cranked mechanism.

The parts were 3D printed in ABS at .3mm layer height, 10% infill.

The tortoise and hare models were remixed to size them and to add an attachment for the dowels.

I used square dowels to insure that the cams do not slip. The pivot is connected to a push pin.

The grass obscures the dowels a little and adds to the narrative of the automaton. It was programmed in TurtleArt then imported into Tinkercad for extrusion and sizing.

I decoupaged the cigar box with the TurtleArt blades of grass design. I printed the design on an inkjet printer then put it into the freezer overnight so it would not smudge when I put the Mod Podge on it.

The finished automaton is whimsical and fun to play with! The box top slides open to reveal the mechanism, or can be kept closed to preserve the mystery of the movement.

The movements complete the narrative: the tortoise plods along while the hare spins freely on the cam and gets nowhere fast.


It was fun to revisit the nursery tale theme for automaton inspiration. I had fun with my first decoupage project and can see doing more of this fun craft. The 3D printed parts I developed earlier were helpful in rapidly constructing this project.