Ustreaming Geiger Counter

With all the interest of nuclear fallout from the reactors in Japan, I decided to get out my geiger counter that I made over 20 years ago. I thought it would be fun to Ustream the data from the counter. My counter has a optocoupler that makes a digital pulse everytime a particle is detected. To stream the data, some kind of presentation is needed to show on Ustream.

Free and useful programs are always welcomed. So I searched the web for a geiger counter grapher and logger. I found one that was suitable. Its called "Digital Geiger Counter" and can be found at Images Scientific Instruments. They have some nice kits for those who don't have a counter. The program connects to an interface at 9600 baud and receives a count for displaying inside the program. They also have instructions for building your own interface using a Pic MPU. I made mine with a Picaxe MPU instead. These are cheap pics that use Basic language for programming. You can get one from Sparkfun and the free compiler from Revolution Education.

Here is a drawing of my Picaxe Interface and program. Its very short and sends the count once a second to Digital Geiger Counter program through the RS232 link. For a more robust interface using a MAX232 use this drawing. You can also program the picaxe through both type of interfaces remotely. This makes it handy if the geiger counter is mounted outside.

To present the data using Digital Geiger Counter, you need a way to present your desktop on Ustream. You can use Ustream's Producer or Manycams as the presenter. Get a free Ustream account, connect your geiger counter and you got your own Web Station off and running. This is my Ustream Geiger Counter Channel. It may or may not be running all the time.

You can view an excel file of the first set of data that I started on Friday, 3-18-11, that ran all night to Saturday morning. Each data point is 1 minute as counts per minute (CPM). The counts seem pretty random and I didn't see any rise in the background radiation. So unless you have a blown reactor in your backyard, you may not see a rise of the background radiation. Here on the West Coast in the SF Bay Area, I'm not seeing a problem.

I also wrote an instructable on this project. You can view it here.

So if you got a geiger counter and can interface a logger to it, get it out and count those radioactive particles. Share with us your results.

Update 3-29-11 Plot of the Counts:

I plotted the CPM on 3-19 and 3-28 to compare value. Didn't see any change. You can download the excel file here.

Update 3-31-11 New Hardware with a PIC 12F675 and 16 mhz xtal.

Schematic: Interface3.pdf
Program in Pic Basic Pro: counter3.bas
HEX code for 12F675: counter3.HEX

Percussus, the drum machine

I always liked the way relays make sounds when clicking on and off. That gave me the idea of using them as a drum machine. I gave it a try and Percussus was born. To control the relays I used a midi interface with a drum sequencer program. One relay is wired as a buzzer, that is, you connect a normally closed contact in series with the coil. A capacitor across the coil softens the tone. The relays are all different sizes and each make there own distinctive click-clack sound. A guitar tuner pickup amplifies the sounds through a homemade guitar amp. Now I just have to learn how to play the drums. A sample of the click clack of little relays can be downloaded here. Website on the project is here. I also did something similar with hard drives. A Instructable (Hard drive after life) shows the process with a different midi interface.

Zi8 on button glows when off

I noticed that the power button on the side of the Kodak Zi8 glows when off. Its just a tiny glow, but you can see it in a fully dark room. At first I thought it was side illumination leaking into the case, but not so in a fully darken room. Could this be wasting power as it sits in the "off" position? What the purpose of allowing the led to light? Could I have a leaky transistor lighting up the led?

16F88 3-digit voltmeter

I wanted to make a simple 3 digit voltmeter for mounting inside a power supply for troubleshooting purposes. Scouting around the internet, I couldn't find anything complete enough to make a meter. So I decided to make my own using Pic Pro basic to program a 16F88 PIC. Micro Engineering Labs has a good tutorial on how to interface a 4 digit led display to a pic. The tutorial was helpful enough that I was able to fashion a circuit and program into a usable meter. Then it dawned on me that the circuit could become an event counter by changing the input stage and program. The event counter uses a 16F628A or 16F88, since both pics have the same I/O pinout.

The circuit is also compatible with a frequency counter I found on the net. This circuit uses a 16F628. Use code "COUNTER3.HEX" for common anode display found at that site. This site got me started in making a multipurpose board.

Below I included links to my programs and schematic for anyone else to make there own. You can use the programs and circuit freely, just don't make money with it.


PBP Basic Program as 100V meter.
Hex file for 16F88 PIC
Schematic in PDF

PBP Basic Program as event counter.
Hex file for 16F628A
Hex file for 16F88

Midi to Relay Controller

I've been looking for a schematic and code for a Midi to relay decoder. I finally found one that actually works well. This circuit will work with sequencer software and commands relays or solenoids with Midi. I plan to make a robot drummer controlled by sequencer software. The decoder required turning on several solenoids at the same time with precision, following notes from a drum sequencer. The circuit and code is free and so is the drum sequencer software (DrumFlow 1.7) that I'm using to test the code. My video on youtube show several outputs turning on at the same time. Just what I wanted. You don't need to wire up all 32 outputs, just use what you need and eliminate the other driver ICs. With just a 16f84 PIC and two other ICs you can drive eight drummer solenoids. Thats enough for a hell of a drummer.

Hard Drive Afterlife

So your aging hard drive can't hold its data any longer and you replaced it with a new one. Instead of letting it die by the hands of the recycling undertaker, you force it into a new life as a musical noise maker. A dying hard drive makes all kinds of grunts and groans as it starts up. The sounds it makes can be musical and percussive.

This project uses a homemade PIC midi interface to allow sequencer software (Anvil Studio free) to turn on and off eight hard drives. Midi signals are serially transmitted by the sequencer software as sets of 3 bytes at 31,250 baud. A PIC 16F877 has been programmed to receive these bytes to turn on and off solid state relays. Each hard drive needs 5 volts and 12 volts to run. Two SSRs are used to turn on and off the hard drive. I tried leaving on just the 12 volts, then switch on 5v to start the drive up. This worked well for awhile until one smoked up. So I use two SSRs to switch on both 5 volts and 12 volts at the same time. A modified PC power supply is used to supply power. A tuner pickup and computer soundcard amplifies the sounds, making the point that something went horribly went wrong with those drives.

The project is for testing the idea of making a larger kinetic/musical artbot "tree" consisting of 24 hard drives. Each hard drive will be mounted as a branch extending from a central trunk in a circular spiral.

This is what happens when you don't throw away broken stuff, you make something cool out of it.

Schematic here.
Pic Pro Basic Code here.
HEX code here.

You can download an mp3 file of the sounds here.
Email me (see my webpage) or leave a comment to check for updates as the code is evolving.

Fix your Garden Light

I bought several cheap Hampton Bay garden lights at Home Depot a few years ago. Part number 498-959. The clear plastic diffuser that supports the electronics has become brittle and fell apart. I suspect its the UV from the sun and has broken down the chains of molecules of the plastic. Instead of throwing them away, I discovered they will fit on top of a Ball canning jar with little effort. First remove the four Philip head screws that hold the two halves of the solar head.


There are four holes already in the solar head. Use two of them with 6-32 machine screws and nuts to attach the canning jar lid. You can see the screw heads in the photo below just inside the lid's rim. In the photo above, you can see the nuts of these two screws

Now the glass won't fall apart like the plastic in the sun. You may need a little caulk around the edges to seal out water. I intend to place mine in my window to light up at night, so theres no water proofing required. If you want more info about the schematic inside, go here to my webpage. I also wrote about the plastic falling apart problem in this 2007 blog.