Raspberry Pi Project Ended

I’ve really struggled with the Raspberry Pi Project. As I posted earlier, the Raspberry Pi kept killing the file system on the SD card. Pete traded me for a different Pi, which behaved much better, making the card last at least long enough to get the operating system and other software installed. Yet the Raspberry Pi continued to corrupt the file system if left running for longer periods. The latest time it totally killed the SD card; I couldn’t even reformat it on my computer.

If I include the Pi in the traveling mascot, I’m convinced it will not survive the inevitable rough treatment. The only other use I can think of for a Raspberry Pi in a travelling mascot is as a home base server for the mascot, publishing the travelogues. Yet it’s too unstable for even that task.

I still like the idea of a traveling mascot that can track it’s own travels, but I’m convinced that building it around a Raspberry Pi is not the proper foundation. I really like the little GPS unit that came in this kit, and will try to build a scaled down version of the traveling mascot with a USB interface to hook up with any computer for collecting data.

Thanks again Adafruit Industries, we really appreciate the kit, and we’ll continue to work with the parts on other projects. Like vultures, some other members have already picked off some pieces of the kit for their projects.

Raspberry Pi Challenge Update


Previously on The Raspberry Pi Challenge

Just a quick update on the “Milwaukee Makerspace Traveling Mascot” project as I caught Eric doing a bit of Raspberry Pi + GPS hacking last night.

Raspberry PI + GPS

I’m excited to see how this project progresses. I’ve not had a chance to get hands-on with the Adafruit Ultimate GPS Breakout yet, but there’s a great tutorial on using it with a Raspberry Pi and one that covers Arduino usage as well.

The Raspberry Pi Challenge!

Raspberry Pi Challenge

Thanks to our friends at Adafruit Industries, we’ve got an awesome Raspberry Pi Starter Pack (and a few other goodies) and we decided that rather than fight over who gets to play with it, we’d issue a challenge to our members: Tell us what you’d build with the kit.

The results are in, and we’ve got a bunch of entries to look at before we decided who will be chosen take on the challenge. Hopefully in the next week or so we can reveal what the winning entry is.

But don’t worry, we’re going to share a bunch of the ideas right here on the blog. We may not get to build them all, but we’ll do our best to highlight some of the ideas that our members have come up with.

(If you’re looking to get into using the Raspberry Pi in your projects, you’d do well to check out the Adafruit Learning System’s category on the topic.)

I am the Cult of “Foamy”

Hello all:

I have been a member here at the Milwaukee Makerspace for about 15 months now.  One of my favorite things to do here is machine architectural reliefs from foam.  I studied architectural history extensively at UWM, so I have a lot of influences to draw from.

The first piece I did was 3/8″ deep, since that’s the bit we had at MMS.  I first tried a piece with all flat surfaces.  It turned out very well, so I tried another piece that has slanted roof surfaces; again, success, so then I did some searching and found a 1/2″ deep milling bit.  I did several pieces “on a theme”, taking the first one and making slight modifications. All of these designs are my own creations, I just daydream and think them up.

I have found that I can get 1/64″ details on these pieces.  I have recently started using 1″ deep bits, and the results are fantastic!  The best part is that the foam is really cheep-cheep-cheep, $25 for a big sheet at Home Depot!

My process is:

1) design in Solidworks (CAD)

2) Export to .STL file format

3) Import into Cut3D, where I generate G-Code

4) Load into Mach 3, the software that controls the CNC router.

5) Let the foam fly!

I started out on the MMS router, which uses leadscrews; my newer Zenbot machine uses belts, and is blazing fast.  I can now machine 8 times faster!  The largest piece shown here went from about 19 hours down to 2.5 hours.

My next challenge is to get small lines onto my pieces that will represent bricks/mortar, etc.  I’ll have to generate different code for that; the milling code runs in 3d, but the “bricklines” will need to be in 2d, so I’m looking forward to that challenge.  I’ll be using Vectric’s “Aspire” software for that.  More to come!



The Critic

This is “The Critic.” It’s the USB accessory version of a red pen: Once armed by rotating the red safety cover up, the device is activated by simply flipping the toggle switch.  When connected to a computer via the convenient USB plug, it will begin to delete text, continually deleting until all the (presumably erroneous) text preceding the curser has vanished. At that point, the safety cover can be lowered, thereby deactivating the device.  The Critic is an indispensable tool for use when the document you’re editing is just so full of errors that your fingers begin to ache from holding down the delete key.  The Critic measures 3″ by 2″ by 2″ tall, and was designed to fit conveniently within arm’s reach, beside your keyboard or mouse.

I was inspired by the open source work of Pete at RasterWeb! and his recent effort to bring “The Button” to a wider audience of busy or non-makers.  He has freely helped tens of people create their own buttons, but is now able to fulfill requests for preassembled units. Among other applications, these USB buttons can be used as the shutter control of  Mac powered Photo booths at public events. These photo booths are powered by Sparkbooth, which can automatically upload the photos to Facebook, Twitter, tumblr or other social media sites.  His buttons emulate a keyboard, and contain an Arduino Teensy (only 0.7″ by 1.2″), which is a USB based AVR microcontroller.  Despite the Teensy cost of $16, I saw an opportunity for cost savings by opening a standard USB keyboard and spending a few minutes to extract and reverse engineer their compact circuit board.  Although this isn’t a solution suitable for even small scale production, it can work for a one-off prototype, like The Critic.

Below are several photos that show the process of opening the keyboard to extract and modify the circuit board.  When the top of the keyboard is removed, a sheet of silicone ‘popples’ is revealed.  These ‘popples’ are the springs under each of the keys.  Under this layer are two sheets of thin plastic, one with conductive ink traces that are (mostly) horizontal, and one with conductive ink traces that are (mostly) vertical.  These layers of traces are separated by a small gap.  When a key is pressed, a protrusion on the bottom of that key’s popple pushes the two layers of plastic together at this location: connecting one of the vertical traces to one of the horizontal traces. These traces are routed to the circuit board via a row of contacts under the front edge:


The chip (under the black epoxy potting on the bottom of the board) detects this electrical connection, and outputs the appropriate character over the USB cable.  The keyboard, popples and plastic layers can all be replaced by an external switch and wires soldered directly to the circuit board.  The photo below shows wires (whose free end is to be connected to the switch) soldered to the pads required to output a space bar character.  To output other characters, simply follow the vertical and horizontal traces to the board, and solder wires to those pads instead.


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