multiplexing hardware

TCA9548A and a dime. Yes, I have
to solder that to a circuit board.

So... I got this chip in the mail from Texas Instruments the other day (if you ask nice, they will ship you free samples...). Looks cool, but it's not even half the size of a dime! How the hell am I supposed to solder each little pin coming off of this damn thing?!

The chip is the TCA9548A 8 channel I2C switch. It was recommended to me by Kerry Wong on his blog article about multiplexing I2C chips. The point of the chip is to be able to connect 4 of my ADXL345 accelerometers to the single I2C input line on the arduino. Now the whole point of I2C is to be able to connect multiple sensors to a single set of input lines; but, to do this, the sensors all need a unique hardware address. My accelerometers all have the same address, so I have to put the TCA9548A in between my I2C input lines and my accelerometers. The TCA9548A allows you to select one pair of input lines as the line to listen to (one out of the 8 supported that is).

28 pin 0.65 pitch TSSOP compatible
prototype board from Schmart Board

I made a quick trip to the local electronics shop and to Radio Shack and all the prototype circuit boards I could find looked like a rhinoceros compared to my little ant of a chip. A little ol' googling of the interwebs led me to SchmartBoard, a little company up in San Ramon that makes prototyping circuit boards that noobs like myself can use to deal with chips this small (That's a Thin-Shrink Small Outline Package or TSSOP for those in the know). And it turns out I was cruising the motorcycle right by their shop on business the next day! So, I stopped in and met up with Neal Greenberg, the VP of sales and marketing. Neal was fantastic and gave me the run down on what I needed to do and hooked me up with this little SOIC prototype board that will fit my TSSOP integrated circuit perfectly.

My next battle is that I've gotta find a soldering iron conical tip with a point that's smaller than 0.65 mm...

Android, bluetooth, and arduino oh my.

[most of this was originally written and posted to FB on 10feb2013]

An onslaught of anti-social sentiments from an overly active couple days coupled with a ridiculous amount of caffeine spurred quite the productive Sunday. What you see here is an android powered HTC incredible 2 (AKA my playa calendar that tells me when to go to what event), paired with a BlueSMiRF bluetooth modem hardwired to a seeeduino v2.21 (basically an arduino). The phone is showing a prototype chat application I wrote that allows me to communicate with the arduino over bluetooth.

This is cool cause it proves that my phone can be used to control my entire suit! So, from my droid, I can tell my entire costume to change from green to purple or switch from being gravity sensitive to being sound sensitive. I'm pretty psyched because this means I (or you!) can change a lot of things about my suit while I'm out wandering the playa and I'm not stuck with just a handful of hardware switches controlling a limited set of options. The flip side is that my arduino can also send real-time info to my phone. With that, I can see the sensor data in real time and have an easier time of figuring out how to make the lights react the way I want.

Most of what I'm doing is on github. The android app I'm showing is here: https://github.com/gerstle/LightWalker/tree/master/tests/android/BluetoothChat and the code that's communicating back and forth with it on the arduino is here: https://github.com/gerstle/LightWalker/tree/master/tests/arduino/bluetooth

Next step? I'm about halfway through creating the first shot of my android app that will control the costume. I've also got all the material I need to make my first modified stilt setup. Well, not all of it... I still need to find some almost see-through white spandex or something. Anybody got any ideas?

first bit of hardware received

Cool Neon toys.

About three weeks back, I got my first bit of goodness related to the LightWalker project -- some killer RGB LED lights, an arduino compatible board, and a developer's shield from Cool Neon  (AKA Funhouse Productions) out of Oakland. I have done a lot of software in my day, but pretty much have zero experience with hardware. I've done a little bit of el-wire soldering along with soldering it onto fabric, but the last time I hooked up an LED to anything and made it turn on and off was roughly 1998. And that was only done like three times to pass my assembly language class.

It took about 30 minutes of mucking around on the interwebs before I had the arduino IDE up and running and made the lights dance. I was hooked! Well, after I made it so I could edit my sketches in Vim instead of the standard editor.

playa coat froggy.

The worst part of getting this stuff and starting to use and understand it was that I soon realized I needed a lot more electronic gear. And sensors! And wires and breadboards and yeah. The local electronics shop failed at all of this; however, radio shack actually saved the day. The local radio shack actually has a lot of cool arduino related stuff and some decent starter kits. Even though some of it looks suspiciously like re-branded versions of stuff from Seeed Studio.

[The only other "electronic" stuff I've done in the last 10+ years is this tree frog climbing up the back of my playa coat. Coincidentally, also done with hardware from cool neon. Where's a rad place to get stuff to make cool things?]

Long story short, within a week I had an ADXL-345 triple axis accelerometer breakout board hooked up to the whole thing and could fairly accurately detect when a step was taken by measuring the g-force applied to the accelerometer against a moving average baseline. Point being, when I walk, pretty lights sparkle every time I take a step. I also realized that having an accelerometer on each limb introduces a lot of potential for some fun light shows. I'll leave you with this example of it's goodness...

LightWalker is born!

I started playing with stilts last summer in prep for Burning Man 2012. In the last nine months or so I've had a fantastic time dancing with The Samba Stilt Circus, wondering around in a kilt on stilts (Kilts & Stilts!), and generally just being a circus monkey as much as possible.

As the new year rolled around and Burning Man released this year's theme, The Cargo Cult, I started thinking about creating some kind of tall, four-legged stilt monster costume to go with that them. I also wanted it to be a night time thing. That requires lights. When I started thinking about lights, I went straight to wanting to make the lights interact with my walking. Eventually this led to me scrapping the alien monster idea and going straight to a huge light display four legged stilt costume.

And so, LightWalker was born!

I've already started in on a lot of it and have some cool stuff to show. I will post most everything here and catch the blog up soon!

Inappropirates.

Inappropriate. But harder to say when you've been drinking.

We were born from a random comment uttered by Jeff over dinner with friends at the 2nd Street Bistro back in October of 2012. His desire was to have a shirt with "Inappropriate" written across the front of it for his birthday that weekend. I'll let the pictures explain the rest...

jeffe

minty.

darren.

scott.

Who are the Inappropirates?! There's a little inappropirate in all of us.