[Noisebridge-discuss] There Was Pizza

[John Radio]

Hi Noisebridge

The Instructables/Jameco hack went down successfully yesterday, Sunday, 
at Noisebridge.

You can view our circuit art, blinking in all it's glory, on the 
worktable against the woodshop wall, next to the reception desk.

I worked with John-who-has-a-British-sounding-accent, plus got some 
scientific narration on the side from Jonathan who makes and sells brain 
devices of some sort. Martin also did some breadboarding with us.

Jameco donated a buncha weird parts to Noisebridge, including LED's, 
crystal oscillators, 555 timers, capacitors.... Our mission: make 
something that does something. Not as easy as it sounds.

The result:
A 9-volt battery driving an LM317 power-supply outputting 5 volts, 
driving a tiny sliver of crystallized rock into resonance at 
one-and-a-half thousand vibrations per second, divided in half, 8 times, 
by a binary counter, down to a speed of about six vibrations per-second, 
driving an LED.

Meaning, we made a light blink 6 times per second.

Then we strapped some LED's onto the next two significant bits of the 
counter, to get blinkers at 12 vibes-per-sec, and 24 vibes-per-sec. In 
red, green, and yellow.

And i'm happy to say, not one 555 was used. This was my design goal 
(since everybody uses 555's for everything).

Video soon.

It's easy to breadboard. If you'd like to build one o these critters, 
all (or most) of the parts needed are sitting on the table next to the 
magnifier lamp.

I recommend you simply copy my circuit. It's the simpler circuit, on a 
single breadboard, with a bouquet of three LED's. Don't copy the other 
two boards (the one's that look less tidy).

Here's the instructable, which will go on Instructables.com (after editing):

Steps:
Hook up the power supply first (battery to the LM317), and hook up a 
voltmeter set to DC to the middle pin (output) and battery negative. 
Twist the trimpot with a flathead screwdriver until you're getting 
exactly 5 volts, or as close to 5 as you can get.

Next, add the crystal oscillator. Notice that there are only three 
connections to the oscillator, even tho it has 12 pins. Connect your 
oscillator output (pin 1) and battery negative to a multimeter that has 
a frequency counter, or use a scope, and ensure you've got a solid 
vibration coming out of the crystal. If you see a 60 Hz signal, that's 
just electrical hum in the air, NOT your oscillator.

Next, throw in the counter. Those connections can be a little tricky, so 
trace your wires carefully. To make the counter work right, send the 
crystal output to counter pins 11 /and /13. There are a couple other 
pins which need to be tied to ground or +V, i will post that info here 
soon. Look at my board to see how i did it. Thanks, 
John-who-has-a-British-sounding-accent for figuring that out.

Datasheets:
if you copy my circuit exactly you won't need to look at these.

Voltage Regulator, which John says is really a current regulator.
http://www.fairchildsemi.com/ds/LM/LM317.pdf

Crystal Oscillator (look at the silver sardine-can on the board to get 
the part number, find the number in this PDF to get the pinouts)
http://pccomponents.com/datasheets/OFC-OSC.PDF

8-bit Counter
http://pdf1.alldatasheet.com/datasheet-pdf/view/28018/TI/SN74LS590N.html
-The datasheet says it has an "output register", but i think they just 
mean it has a parallel output (vs. a serial output, which sends 8 bits 
of data out through one pin).

-Mod: The goal is to get some irregularity or syncopated pattern with 
only a very simple hack. Try sending a DIFFERENT crystal oscillator, 
running at a different speed, into the "register clock" or another input 
on the counter. I have no idea what it would do-- likely nothing 
interesting. Note, using a faster crystal is not desirable, since that 
will just give you blinks that are too fast too see.

Parts that get connected to the LM317 power chip:

2 Caps
1 uf and .1 uf. The numbers on the caps say 104 and 105. Just see what i 
used.

A trimpot.
You'll need to find a 1k trimpot in our component corner. Good luck. Try 
Radio Shack.

A resistor.
About 250 ohms.

And, yes, there was pizza. 1/2 vegetarian with pesto and garlic, 1/2 
pepperoni with extra cheese. Make a note of it.


Johny Radio

Stick It In Your Ear!

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