A group of us from HackPittsburgh (Matt S., Marty, Mandy, and I) took an action-packed trip up to NYC this weekend to attend the Arduino Meetup, and got to visit Adafruit Industries, ITP, NYC Resistor, and Alpha One Labs. Thanks to everyone that took the time to meet with us and show off what they are working on, we had a great time! Full photo set is here.
Here is a pretty simple end table that I built using some scrap wood and nails. If you’ve got some extra veneered plywood, finishing nails, and access to a chop saw and band saw (don’t have them? join Hack Pittsburgh!) it should be pretty straightforward to make your own. The pillar is made up of four identical rectangular pieces and two small square pieces. The rectangle pieces are mitered along their long edge, and the square pieces are then sized to fit into the center hold formed when the rectangle pieces are assembled into a pillar. Once they were cut, finishing nails were used to assemble the pieces into a square pillar. Finally, the top was made of two larger square pieces, which were nailed onto the pillar in an arrangement that seemed pleasing. Sharp edges were sanded down, but no further finishing was applied.
Once I got it home, I added a lamp and a set of typographic character coasters given to me by Windel and Lenore of Evil Mad Science Laboratories. I’m thinking I will do a more polished version of the nightstand once I get my engraving machine working 
To escape the plastic world for a bit this weekend, I headed out to the Phipps Conservatory for some organic scenery. Though I was a big fan of the Desert Botanical Garden in Phoenix, I’ve only been to Phipps a few times since I moved to Pittsburgh. The desert room here saddens me. Though it is laid out well, I miss the smell of creosote bush, and have to fight the urge to put on my hiking boots and head west. Turns out I miss Arizona!
Anyway, this is a pleasant place overall, wonderful smells, colors, and sounds (even the pre-recorded bird calls- either a nice touch or an extreme annoyance). I took a couple of photos, but mostly just sat and observed. The sheer variety of shapes and colors produced by our floral friends can be quite overwhelming.
I did pick up a membership, so if’n you ever want to make a visit there, let me know.
Collin sent me a pre-release sample of his MidiVox kit to try out, so I dutifully soldered it up, and then proceeded to have some fun with :-). It’s a cool little add-on shield for the Arduino, consisting of a MIDI input jack, DAC and audio output jack, allowing the Arduino to act as a MIDI synthesizer. The board and components are beautiful, with cool curvy traces (which I suggest you consider from an aesthetic standpoint, not an engineering one) and solid connectors, and I had little trouble assembling it. The kit included 5-banded resistors, which I didn’t remember how to decode, (it turns out they are higher precision then their 4-banded cousins), but a multimeter did the job just fine.
Once it was all put together, I grabbed the pre-release version of the software, and after working through some issues to get it to compile on my Linux system (filename case sensitivity, we make everything difficult!), and uncovering (and fixing) a bug in the Arduino environment that prevented a supporting library from compiling, the sketch uploaded fine. I plugged in a MIDI patch cable and was busting out melodies from my MIDI keyboard in no time.
Then, OCD mode kicked in, and strange things were made to happen… Becasue my keyboard only has one adjustment knob, I wasn’t able to use it to tweak all of the synth parameters, so I wrote a PD sketch to expose all of the knobs:
Then, I decided that I really wanted to use a sequencer to feed the MidiVox, so I fired up Seq24 and made some patterns, throwing in a drum track generated by QSynth. This was all working great using the MIDI out through my keyboard, but I realized it would be much more convenient if I could control it directly through the USB connection. Well, Steven Hobley recently made a program to achieve this in Windows, but I couldn’t find anything like it for Linux. Instead, I hacked up a copy of ttymidi to work backwards. It’s a pretty incomplete implementation of a serial->MIDI bridge (ideally, it would support bidirectional messages of all kinds, not just note on/note off/control), but it seems to do the job. If you are interested, the hacked-up mess is here, and be sure to set your Arduino to 38400 baud.
At the end of it all, I was able to relax on my couch and control the MidiVox directly from my laptop, without a MIDI cable in sight… quite a bit of fun! If I get inspired sometime soon, I’ll try to clean up the hack job I did to ttymidi, and release it properly.
Extended the controller to handle all three drive axis, so now we can draw some things. Here is what came out:
Props to Matt S. for gently reminding me that this doesn’t require a super complex system, and that some tape and open loop controls are probably good enough :-).
Project code is now on github!
Finally getting around to designing up a stepper motor controller for this chemical mixing robot that I picked up this summer. So, here is a super simple controller to drive one axis! Right now it’s using Arduino on an Atmega168, but I think i’ll switch to something lighter, give each module it’s own micro (with limit switch and encoder support), and talk to them from a master controller using some serial bus. Or just talk to them all using a parallel port on a PC ;-). Sample code for this guy after the break.
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I’ve been on a bit of a baking kick lately. I’d been making a country loaf recipe, but decided to try out a French bread recipe this time. I like the taste of it, however purists might argue that it isn’t quite right stylistically- the crust is crunchy but not exactly hard, and the insides are warm and i think a bit denser than might be expected. Which is actually my favorite texture for bread, so I’m not complaining :-).
Following this recipe.
