brainwagon

Greetings readers. I’m hopefully wishing there is still more than one.

This weekend was the Bay Area Maker Faire 2015, the 10th incarnation of an event which has become increasingly (even frighteningly) popular. I’m tempted to channel Yogi Berra, who said “Nobody goes there. It’s way too crowded.” Anyway, I got out of my house around 9:00AM, with the plan of parking at one of the offsite parking lots and shuttling in. It took me about an hour to get to the Oracle lot on 10 Twin Dolphin Drive, and there were already probably six or eight busses lined up, but probably a thousand people lined up as well. As it happens, it took slightly more than an hour to make it onto a shuttle, drive in and enter the gates. Bleh. Not the most fun, but I had a good nights sleep the night before, so I was mostly in good spirits as I entered the park.

It was very crowded. I was by myself, so I just started wandering. When I go to these things, I am mainly looking for three things:

• Projects that inspire new projects.
• Cool new products, especially inexpensive dev boards and gadgets for future projects.
• Cool artwork that I haven’t seen before.

Sadly, I didn’t see a ton of projects that made me think of new projects, but there were a couple. I had a nice chat with Ben Krasnow who brought some low-tech versions of his excellent rheoscopic coffee table, which were just plastic cells that rotated on a lazy susan. You’ve probably seen identical gadgets in science museums. Fluid flow is always interesting. He said the instructions were already on the Make Magazine site, but I forgot to copy the url, and didn’t find it. He also said it would be in the print edition sometime soon.

I had a nice chat with Erin Tomson of Modulo Labs LLC. She’s a former Pixar colleague, who has gone off and created Modulo, a set of pluggable programmable modules that can be used to assemble modules in a tiny, secure network, without the hassle of routing jumper wires on breadboards. (In fact, a system like this would have prevented a lost hour of my time tonight, I’ll tell that story below.) It’s a very slick little system, and I’d like to see something like this take off. I can particularly see this as useful in education.

Check out her Kickstarter video.

I particularly like optical gadgets like telescopes and microscopes. My buddies Rich and Dave from the Chabot Telescope Makers Workshop were there, grinding away and answering questions about telescopes. Nice to catch up with them. They said that quite a few people came up to them and asked “So, you guys sell telescopes?” Sigh. This is the Maker Faire. If you are in the North Bay and want to learn how to build a telescope, click on the link above, and think about attending one of their free workshops (every Friday!).

I like projects which reuse camera phones, and this microscope project seemed pretty cool. They had a little gadget that allowed you to swap out three different lenses to get different magnifications. Their system seemed pretty cool, but the basic idea is pretty simple (in fact, it’s basically a version of Antonie van Leeuwenhoek’s first microscopes, but instead of holding it close to your eye, it’s held close to your cell phone, which can use nifty features like zoom and exposure adjustments, and can of course record video and stills. I should design such a gadget myself.

I also had a nice chat with Alan Yates who was demonstrating some “Lighthouse” technology that he’s been working on at Valve. The basic idea is to create a set of “beacons” that can be scattered around an environment, and a sensor that can (for instance) be mounted on a VR headset and can be used to figure out the position and orientation of the headset with high accuracy and low latency. I don’t have a link for this work yet (did I miss it, Alan?) but when I do, I’ll try to update it.

That was kind of it. I did poke my nose into various people experimenting with aquaponics, which I find interesting. I had a brief chat with the creators of Chip, the $9 computer currently on Kickstarter (I hope to have more information on that soon, stay tuned.) I didn’t spend much time in the “Dark Room”, the noise and flashing gives me a headache. I did spend some time looking at the various gardening and bee keeping exhibits.

And, I did pick up some new gadgets. Here’s a short video of my purchases, along with some links to the various items mentioned.

• My old PMB-648 GPS Module (obsolete)
• Adafruit Ultimate GPS Module. New, can do 10Hz updates, and has a 1PPS output. Much better.
• I got two Teensy 3.1 boards for just $15 each. Very cool.
• TI MSP EXP430F5529 Launchpad Low power, and cheap dev board, should be supported by platformio.
• A Spark.io Particle Photon Kit Spark.io has changed their name to Particle, and then did a deal with Sparkfun to build additional add ons and distribute the Photon. I don’t know a lot about the Photon yet, expect some posts about it in the future.
• A little wireless keyboard from dfrobot.com. Hooked it up to my Raspberry Pi in my living room, and it seems to work pretty well. DFRobot appears to have their own line of Arduino clones, including ones that do Bluetooth Low Energy at fairly reasonable prices. Might be worth checking out.

And that’s about it. If anyone thinks I missed something super cool, drop me a comment below and I’ll check it out.

Today, I had a bunch of chores to do, but I did start to play around with my AD9850 project a bit more. Since I spent so much time driving around yesterday, I had lots of time to think, and realized that the code the determined the tuning word (the 32 bit value used to select the frequency of the oscillator) was probably going to not work properly, since it used floating point arithmetic, and that probably didn’t have sufficient precision to do the calculation the way that I had coded. Indeed, when I got home, I hooked up and Arduino and found that I was not getting the sub-Hz spacing that I requested. I played around with the math a little bit, and got it working better, and then set it up and started it going. I had the output of the AD9850 going into my oscilloscope, so I could monitor the waveform.

And it was glitchy. Intermittent. Not working properly. Had I made a programming mistake?

I spent the better part of 45 minutes trying to understand how I had broken the program. Nothing made sense. I was cranky. I decided to step back and go buy some cat litter than I had forgotten, and give it a rest.

And of course when I got back, I stared at the board again. And it was immediately obvious. I had the AD9850 module on a breadboard, with all the RESET/CLOCK/LOAD/DATA lines going to the Arduino. And… that was it…

There was no common GND. I had somehow tugged out that little jumper wire. Without a common ground, it was surprising that there was any communications between the module and the Arduino.

Plugged it back in and voila. All works. Sigh. An hour of my life, wasted.

Suddenly, Erin’s Modulo setup seems pretty nifty. 🙂