Author Topic: animated fez tassel (hackathon project and beyond)  (Read 1572 times)


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animated fez tassel (hackathon project and beyond)
« on: February 10, 2013, 08:55:50 PM »
 After chatting w/ Lance for a bit about the haptic "feelspace belt" it seemed like something along those lines woud be interesting, but having a bunch of pager motors buzzing around my head all day would probably never become non-annoying. On the other hand, teaching the tassel of my fez to always point north might be doable, and still silly enough to be fun.  (Having it point to the nearest coffee shop would be ideal, but beyond the scope of the weekend.) 

When I got home, I dug around and found an I2C magnetometer thing that was supposed to be part of the ardupilot 1.0 rig that became obsolete long before I got around to putting it together.  After  fiddling around with it on the raspberry pi for a while, I gave up, and hooked it up to an arduino, and proceeded to get numbers out of it that seemed to change depending on which way it was pointing, but which didn't make much sense to me.  At least that was a start.  The next step was to track down either a 360+ degree servo (aka a drum winch for an rc sailboat) or a continuous rotation servo. I didn't have a drum winch thingie, but was pretty sure I had a parallax continuous rotation servo.  After a lot of rummaging, I found my parallax servo, but it was a standard servo, not one the continuous ones that were on that BOEbot that I left with my friend's kid in Seattle.  Radio Shack carries them, but none of the stores around here had either the servo or a BOEbot kit in stock. RC store didn't have either a drum winch or a continuous rotation servo.


Okay, maybe I could just make the tassel move back and forth whenever someone tweets something with hashtag #familab or #davethatfezismagnificent or something similar.  i could have a pi watch for the tweets and notify the fez via xbee->air->xbee->ATtiny4313->standard servo.
That seemed doable. Next step: see if I can even program the chip to move a servo.

I proceeded to spend a good chunk of time figuring out how to set up my 28pin zif socket programming shield thing ( so it could be switched easily between programming ATtiny85's ATtiny4313's and ATmega328's. I added a few header pins, and a few female jumper wires, and although it wasn't nearly as cool as this guy's shield, I was still pretty happy with it.  Since rumor had it that the toolchain for the 4313's was a bit, um, unpleasant to work with, I started out testing it with an ATtiny85. (I've been wanting to try one of those ever since Tetsu showed me how back in 2011.)

I got it to blink!

The standard arduino servo library doesn't work very well with the 85, but I found a library that did at

I got a servo to move!

I then wandered down the rabbit hole of trying to get the toolchain working for the 4313. After a lot of flailing around, I ended up fudging the signature and treating it like a 2313.

I got it to blink!

Then I tried the servo lib, but apparently there was enough if-def-ery going on that the compiler didn't think it would be a good idea let me try.

Even after commenting out a lot of things and copying and changing a lot of things.

Time was running out. At this point, I could have just used blink to trigger a relay/transistor/whatever and spin a regular motor, but since I could also do that directly with the xbee, I'd essentially just be using the 4313 as a piece of wire, which kinda misses the point.

In the end, I built a programmer that I've been meaning to put together for years, and did it with enough jumpers that I can use it on a variety of chips.  I spent sufficient time experimenting with 85's and then wrestling with a broken 4313 toolchain that by the time I gave up,  working with ATtiny85's actually felt felt pretty comfortable. Thank you Abyss, this was a lot of fun!


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Re: animated fez tassel (hackathon project and beyond)
« Reply #1 on: February 16, 2013, 03:35:43 AM »
Crap this would be awesome. Coffeeshop is definitely the pinacle so far.
I like colors.