Supernatural EMF detector

[thatdecade]

My version of code and circuit schematic.

This will read EMF from an antenna, display on the LED bargraph, and play sound when a preset threshold is reached. In addition, there is an override button to force the sound and animation to trigger.

Not coded yet:

• Analog Meter output
• Threshold selection by potentiometer
• Mode selection (demo/prop mode)

Arduino Code:
https://codebender.cc/sketch:28269

Circuit:

Demo Video:

 

[Sulla]

My version of code and circuit schematic.

This will read EMF from an antenna, display on the LED bargraph, and play sound when a preset threshold is reached. In addition, there is an override button to force the sound and animation to trigger.

Not coded yet:

• Analog Meter output
• Threshold selection by potentiometer
• Mode selection (demo/prop mode)

Arduino Code:
https://codebender.cc/sketch:28269

Circuit:
[url]http://farm8.staticflickr.com/7290/12094754483_c44303bf6b_m.jpg[/url]

Very cool! Great job.

 

[thatdecade]

I still need to keep playing with that sound, is a basic approximation right now. I think I can get closer by mixing multiple frequencies to the speaker. Data I am using to generate the sound is below.


EMF Sound Sample (2 seconds):
Mediafire - emf_sample.wav

EMF Sound Sample - Spectrogram Analysis:


If you look closely, you can see the highest high tone in the center. A heavy 1000hz with a light 2000hz mixed in.

 

[thatdecade]

That plan sucked, lol. Instead, I went with a PCM audio library, converted the audio, and stored the entire shortened clip in arduino memory.

Normally PCM playback is dependent on an SD card to store the large .wav file data, but a small tweak and you can store the .wav file locally (without an SD card). You just have to keep the data small, under 4 seconds small.

Brief demo of the audio: https://www.youtube.com/watch?v=mEpeiSOC9lc


Next step is splitting up that short clip further into sections. Looping the different sections to be longer, etc.

 

[RichLather]

I'm about ready to dive headfirst into this, but it seems the parts list from FriedGeek is completely gone. Thanks to the work of many others in this thread I know I can get the LEDs, some of the switches and potentiometers, the Syntax board and a Draper multimeter to begin with, but I'm wondering if more complete parts lists and Arduino circuit diagrams are available, or being played close to the vest. I suppose I can pore through electronics catalogs if that's what it comes down to.

I'd dearly love to make one of these, especially with thedecade's recent work with the squawk sound. Sure, I could buy one, but I want the challenge and learning experience of assembling and programming one.

 

[thatdecade]

I too am working on an updated standard part list. Currently, I am still missing:

• the square resistors (top)
• antenna holder clips

Some progress I have made. Designed a custom pcb to make the additional arduino circuit better hidden. Leaving the work area untouched so that you have to run wires to the knobs and switches, still giving the emf reader that hand made look.


You may notice that some of the square pads are missing a hole. Those are fake vias to hide the backside circuit. The mockup doesn't show the solder mask layer very well. I assure you that each shiny square will have a dark spot in the center.

 

[thatdecade]

Overview of the parts I have found so far. Still missing those box looking resistors located under the LEDs.

Specific Part List
Use these exact parts for accurate 'do dads'

• Prototyping Board - Syntax PC 462904 - circuitspecialists
• Toggle Switch - C&K 7101 - digikey
• Trimmer Pots - 3362U-103LF-ND - digikey
• Thumbwheel Pot - 3352T-103LF-ND - digikey
• Antenna Clips - Clear 1/8" P-Clips - fiberopticproducts

Generic Part List
These are the parts I am using, use what you can find local and cheap

• Telescoping Antenna - radioshack
• Analog Multimeter - menards
• Colored Hook-Up Wire - radioshack

Powered Part List
These are additional parts to make the 'do dads' light up and do things.

• Battery Clip
• Resistors
• Arduino
• Mini Audio Amp
• Mini Speaker

 

[thatdecade]

Couldn't find the right square part because they are not resistors, are suppression capacitors with 10mm lead spacing.


Quick reference
Identify various capacitors and understand their specifications | Marine Notes
.

Yellow - Cornell Dubilier MPX
MPXQS22K Cornell Dubilier | Mouser

White - Kemet PME
PME271Y447MR30 Kemet | Mouser

and Red, because... - Wima MKP10
MKP1G023303F00JSSD WIMA | Mouser

 

[thatdecade]

I am getting close to making a full run through on the protoboard before final assembly. :cool



Here is the analog meter graphic I threw together.

Supernatural EMF Graphic by thatdecade, on Flickr

 

[phillydon21]

I too am working on an updated standard part list. Currently, I am still missing:

• the square resistors (top)
• antenna holder clips

Some progress I have made. Designed a custom pcb to make the additional arduino circuit better hidden. Leaving the work area untouched so that you have to run wires to the knobs and switches, still giving the emf reader that hand made look.

http://farm3.staticflickr.com/2839/12234930653_51913c3c16_o.png http://farm6.staticflickr.com/5497/12234930083_79597d887d_o.png
You may notice that some of the square pads are missing a hole. Those are fake vias to hide the backside circuit. The mockup doesn't show the solder mask layer very well. I assure you that each shiny square will have a dark spot in the center.

I think i might have some extra left over from when i did mine if you still need them

 

[thatdecade]

I'm interested

 

[RichLather]

Next step is splitting up that short clip further into sections. Looping the different sections to be longer, etc.

By this, may I infer that you want to split the short WAV into three parts? And if I may illustrate with onomatopoeia, I see it as "erREEEEErr". Perhaps split the clips into "eeR" "EEEE" and "Err", and loop the middle "EEEE" for longer sections?

 

[thatdecade]

Correct. The EEEE and eeee sounds are the trickiest as they must be looped for the high and low readings. The looped sounds get a little glitchy on the transitions.

I have the looped audio written up in code, but didn't take a video because I didn't like the way it sounded with the looping. Still needs some re-work.

 

[thatdecade]

I didn't like how the emf readings were going so I changed the circuit to be a crude light sensor. The readings will now indicate proximity to other objects. Meaning every object you "scan" will give a reaction.

The potentiometers are for calibration of the high and low sensitivity.

Circuit:

Light / Proximity Bargraph by thatdecade, on Flickr


Source Code:
https://codebender.cc/sketch:30543

 

[Loompa2000]

Great work guys! I'd be interested in purchasing one if anyone plans to make additional ones once the prototypes are done!


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[DeadRoach]

Sorry if I missed it, but has anyone identified the black piece on the front/bottom of Deans emf?

 

[Sulla]

Sorry if I missed it, but has anyone identified the black piece on the front/bottom of Deans emf?

I am sure someone has. I thought it was some kind of potentiometer.

 

[thatdecade]

Do you mean this?

Thumbwheel Pot - 3352T-103LF-ND - digikey

Instead of buying one, you can salvage a pot wheel from a volt meter. The same volt meter you are salvaging an analog display from.


IMG_2240.JPG by thatdecade, on Flickr

 

[DeadRoach]

I was looking for the boxy looking thing in the middle

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[Aposstle]

Hey guys! Is anyone still making any of these for people who want to buy one? Just thought i'd check coz it's a pretty old ongoing thread now!