Posts Tagged ‘maker faire’

Upcoming events: OHS, TAPR DCC, NYMF

Sunday, September 1st, 2013
OSHW summit goodie bag

photo credit: adafruit

There are three major events of interest to open source hardware and makery folks this month:

I’ll be at OHS and TAPR, but have to skip the NY Maker Faire this year.  I imagine that far fewer folks from OHS will be attending NYMF now that those events are no longer co-located.

Sorry NYMF, but I can’t turn down an excuse to visit my friends in Harvard square.

The Seattle Mini Maker Faire is next weekend!

Sunday, June 2nd, 2013

smmakerfairestranger

The 2nd(?) annual Seattle Mini Maker Faire will take place next weekend (June 8th-9th, 2013) in the Northwest Rooms at the Seattle Center.

I’ll be there showing off my Glowy Geiger Chimes and selling open source Geiger counter kitsAlan is bringing his Glowputer, and many other Seattle-area makers will be there (here’s a list).

See you there!

Come see my Glowy Geiger Chimes at the 2013 Maker Faire Bay Area!

Sunday, May 12th, 2013

It’s that time of the year again! The 2013 Maker Faire Bay Area is next weekend (May 18-19th) in San Mateo, California.

I haven’t had time to post about it, but over the past few weeks I’ve been busy working on a special project for the Maker Faire this year.

This year I am bringing a new and improved version of the “Geiger counter-powered ambient music thing” that I threw together at the last minute last year (and never really came up with a good name for). In that project, I connected five of my open source Geiger Counter kits to an Arduino that sent MIDI commands to a Sparkfun Music Instrument Shield. When each Geiger counter was triggered by background radiation or one of the weakly radioactive sources nearby, the Arduino would send a command to the shield to play a musical note.

This year I’m bringing a new and improved version that uses a new piece of hardware that I designed specifically for the Faire – the Geiger Pad.

Each Geiger Pad contains a fully functional Geiger Counter based on my Geiger counter kit. The output of the Geiger counter is connected to a cluster of 14 very bright 5mm UV LEDs. On top of the Pad is a petri dish filled with uranium marbles. Each time the Geiger counter detects that a gamma ray was emitted by the marbles, it flashes the UV LEDs. Since the uranium marbles fluoresce green under UV light, this produces a brilliant green glow.

Today (yes, once again at the last minute) I finally got all the pieces together and working. If you come to the Faire you’ll be able to see it in person, but I also posted a short video on flickr:

The Maker Faire website lists me in Expo Hall, but it’s more likely that I’ll be somewhere in the dark area of Fiesta Hall instead. Check the Maker Faire website later in the week for more details.

See you at the Faire!

Glowy Geiger Chimes at makerfaire.com

My Hardware/Maker/Arcade/Pinball Geeky Events Calendar 2013

Sunday, April 21st, 2013

It’s officially event season!  I was sorting through my calendar this afternoon and I thought I’d share a few geeky hardware/arcade/pinball/open source/hackercamp events that I’m looking forward to over the next few months.

April 22-25: DESIGN West, San Jose, CA.  I’ll be there.  Joe Grand is speaking on Wednesday

May 18-19: Maker Faire Bay Area, San Mateo, CA.  I’ll be there with a booth this year (Glowy Geiger Chimes).

May 17-19: Dayton Hamvention, Dayton, OH.  I want to check out this HUGE ham radio event sometime, but my attempt to go to Dayton this year was thwarted because, yet again, it falls on the same weekend as the Maker Faire.  Maybe next year.

June 2-7: MTT IMS 2013, Seattle, WA – Expo is free on Wednesday

June 7-9: Northwest Pinball and Arcade Show (NWPAS), Tacoma, WA.  Definitely checking out this local show this year.

June 8-9: Seattle Mini Maker Faire, Seattle, WA  (Another geek event collision, this time in Seattle.)

June 22-23: ARRL Field Day

July 13-14: California Extreme (CAX), Santa Clara, CA.  This might be my first year at CAX, if I don’t have to cancel at the last minute like last year!

July 31-Aug 4: OHM2013, Geestmerambacht, NL.  Deadline to submit a talk is May 1st.

Sept. 6: Open Hardware Summit, MIT (1st year held separately from the World Maker Faire!)

Sept. 21-22: World Maker Faire, Queens, NY.

Did I miss anything?  What other events are folks excited about?

Pics & video of my Geiger counter powered ambient music demo @ Maker Faire

Thursday, May 24th, 2012

IMG_5420.jpg

(photo credit: alvaroprieto)

This year I decided (in true last-minute fashion) to build a couple demos to show off my Geiger Counter kit at the Maker Faire Bay Area. One of these demos used my Geiger Counter kit to create ambient music:

(Thanks to @j_jwalrus for the interview and video!)

I used a five MightyOhm Geiger Counter kits, an Arduino Uno R3, a Sparkfun Music Instrument Shield, and an Adafruit Protoshield to make the demo.

Last minute project for the Maker Faire

The PULSE output of each Geiger counter is connected to one input of a 74LS04 hex inverter on the Protoshield. Each time a Geiger counter detects a radioactive decay, it sends a 0.1ms 3V high pulse to one input of the inverter. The 74LS04 functions as a level shifter and outputs an (inverted) 5V pulse that is suitable for driving an ordinary (5V) Arduino.

Five outputs of the 74LS04 are connected to input pins on the Arduino. For convenience, I used Analog inputs 0-1 as digital input pins. The rest of the gates are connected to digital pins 10-12.

I used the PinChangeInt library on the Arduino to trigger an interrupt handler every time a falling edge is detected on one of the geiger inputs. This interrupt handler stores the pin number to a variable and sets a flag to tell the main() function that something has happened.

The main() loop polls the interrupt flag and waits for something to happen. When it detects that an interrupt has occured, it sends a “Note On” midi message to the Music Instrument Shield, using the SoftwareSerial library built in to Arduino 1.0. I had to hack the library a bit to get it to work in conjuction with the PinChangeInt library, since the SoftwareSerial library automatically installs interrupts for all pins (bad, bad SoftwareSerial!)

The value of the note depends on which Geiger counter triggered the interrupt. In the video I am using note ‘C’ over five octaves, centered around middle C (midi note 60). (I am not a musician, but this seemed to provide a pleasing sound that wouldn’t annoy me or my neighbors at the Faire too much.)

The Arduino sketch is a complete disaster right now, having been thrown together at the last minute, but I plan to clean it up and post it soon.

Things I learned while creating this demo:

  • Sparkfun doesn’t include stacking headers with their shields unless you buy them in retail packaging. $30 in overnight shipping fixed that.
  • Arduino is still a pain to program for if you do anything moderately unusual, like try to use two libraries together that both use pin change interrupts.
  • You can get away without issuing “Note Off” commands for midi instruments that fully decay. (I think the MIDI spec frowns on this, but it works on the Sparkfun shield, at least.) This greatly simplified programming the demo, so I took advantage of it!

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