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For the discussion of Arduino related topics.
By brinstar
#159073
pretend i don't know anything about programming arduinos or designing circuits. i have a challenge for you, and here's how i want this to go: i explain what i want to build, you help me with the schematics and code, i put it together myself, it works, i send you some sort of compensation (i.e. gift card to newegg? i dunno, we can talk about that later)

so here's the deal. i'm in a weird 80s pop funk band. i want to put together a jumpsuit with a large amount of EL wire sewn onto the outside, which reacts in realtime to environmental sounds and is controlled and powered by a small pack that will fit into one of its pockets. that's the basic concept, though i do have some additional requirements:

1. power supply must provide at least 90 minutes of continuous use
2. there will be 3-6 different colors of EL wire
3. each color of EL wire will be activated by sounds within a certain frequency range (i.e. red wire triggered by sounds below 200Hz, orange wire from 200Hz to 700Hz, etc)
4. the intensity of the EL glow will directly correspond to the intensity of the ambient audio within those frequency divisions
5. there needs to be a way to fine-tune the sensitivity of all the different frequency ranges, as well as a "master" knob that adjusts the sensitivity of the system as a whole

SO

the arduino needs to receive ambient audio signal, that signal needs to be split into different frequency ranges, the amplitude of signal in each frequency range needs to be expressed dynamically by pushing a corresponding amount of power through its color of EL wire, and all this needs to happen in realtime (i.e. with as little latency as possible). also i need the ability to tweak overall system sensitivity on the fly, because too much signal means the EL wire is always on, and not enough signal means nothing happens


i can afford to drop up to $150 on components, not including the jumpsuit itself. i just need someone to design the schematics and code for me so i can build the thing because i generally learn by doing. any takers?
By MichaelN
#159297
brinstar wrote:...I explain what i want to build, you help me with the schematics and code, i put it together myself...i just need someone to design the schematics and code for me so i can build the thing because i generally learn by doing. any takers?
I think you’ll find that people around here will be happy to HELP you with schematics, code etc., but aren’t going to do the work for you. If there was enough interest, you might get more help by making it an open-source project.

There are some here who would probably take it on as a commercial job (which would probably cost thousands of dollars), but it doesn’t sound like that’s what you’re proposing.
By Mee_n_Mac
#159316
MichaelN wrote:.. but aren’t going to do the work for you.
Yeah, that sounds like ... work. :twisted:

I believe you could assemble the whole electronics package from parts SFE sells. About the only thing that needs some thinking is the dimming function. I believe it's been shown that simple chopping of the AC waveform, as is done in a household light dimmer, doesn't work so well. Or rather while it may work, the result is blown triacs after a while. Seems the preferred method is to modulate the AC output voltage amplitude by varying the inverter's input voltage. I wouldn't think this would work with all inverters. Perhaps SFE should look into designing a dimming inverter, perhaps one with 8 independent channels of output. :wink:

Alternately I think you could make a dimming circuit by chopping the waveform more intelligently. That is enable/disable the triacs at zero crossings only and skip some cycles every 20 msec or so. Now you need a just-before-zero crossing circuit. Given the frequency of the waveform used, you might get a reasonable range of dimming this way. Or not, I've not seen it tried.
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By CircuitBurner
#159388
I used to build motorcycle 'regulator rectifiers' for sportbikes and racing bikes cause the stock ones burn out in a year or two usually, if you ride fast alot.

One of the components that was critical to the regulator circuit being able to throttle down the voltage when engine is revving fast was the lowly SCR...and not just the generic SCR packages...I used the big metal bolt looking versions that hard-mounted to heat sink surface to bleed off the heatr the SCR made when basically "shorting to ground" the excess current....was a simple method, and relied on a kickass SCR to carry the load of heat and abuse....
Maybe on this task you might employ some beefy SCR to choke down (short) the current for dimming / flashing...
Might be really utilitarian when used in cold weather, and the heat sinks for SCRs could contribute to warming garment..
LOL