penabled
New Member
I'm just gonna leave this here: http://shop.evilmadscientist.com/productsmenu/793
Want to Make my LEDs Flicker!
- Thread starter MythMaker
- Start date
Just viewed the video. Yeah, agreeing with x197 on this one. Custom PCB will save you on scale if you are doing more than 3-4 of the things. Surface-mount LEDs, pre-programmed ATtiny controller with slice-and-solder PCB traces to select the behavior on a unit-by-unit basis. External LiPo or coin cell holder soldered right on the board. Biggest cost outside of the batteries themselves is fab cost for short-run; I use OSHpark and it works out to about five bucks a PCB in prototype runs.
I'll probably regret this (deep in tightening up the programming on my Holocrons right now) but I've got Eagle open and if you shoot me accurate scale drawing/measurements I'd be happy to work up a board for you. I've got a baby reflow oven too...I might be talked into soldering a few up (probably would want to do one myself just to test the PCB and dial in the programming).
I'll probably regret this (deep in tightening up the programming on my Holocrons right now) but I've got Eagle open and if you shoot me accurate scale drawing/measurements I'd be happy to work up a board for you. I've got a baby reflow oven too...I might be talked into soldering a few up (probably would want to do one myself just to test the PCB and dial in the programming).
xl97
Master Member
OSH park has GREAT quality PCB! (good mention!)
That being said.. if you can 'wait'.. you can get 10 x pcb's from China for roughly $10 bucks.. (I think its like another $5 to ship?)
yeah.. post the dimensions!
OD, ID... and thickness of 'prop' (and how much room under it you have to practice your 'cram-fu'!) LOL
@OP.. if you get myself or nomuse to whip you up a PCB in Eagle.. the hardest part is done for you.. just order and get to populating the pcb's..
if you get myself or nomuse to also populate said pcb's... then you can focus on the code, (which if you are new to all this, can be a daunting task in-itself).
but with nomuse and myself here to guide you.... you should have one kick-ass prop in the end!
That being said.. if you can 'wait'.. you can get 10 x pcb's from China for roughly $10 bucks.. (I think its like another $5 to ship?)
yeah.. post the dimensions!
OD, ID... and thickness of 'prop' (and how much room under it you have to practice your 'cram-fu'!) LOL
@OP.. if you get myself or nomuse to whip you up a PCB in Eagle.. the hardest part is done for you.. just order and get to populating the pcb's..
if you get myself or nomuse to also populate said pcb's... then you can focus on the code, (which if you are new to all this, can be a daunting task in-itself).
but with nomuse and myself here to guide you.... you should have one kick-ass prop in the end!
propmaster2000
Sr Member
MythMaker,
Are you still going to use an external power supply (battery pack 8AA) and 9 LEDs per watch?
If so, then the Blinky/Flicker circuit can be external as well (and as you said earlier, between the power and LEDs).
Just wondering what your thinking is now on this and do you have a more accurate description and measurements
of the prop itself (sketch, drawing, diagram, etc.)?
propmaster2000
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Add to the questions -- is the 12v bus part of the costume design? Would you prefer individual batteries? I think I know how you ended up with 3x3 LEDs but do you need individual control of each set of three (in the video, looks like the entire face flickers as a unit)?
propmaster2000
Sr Member
It sounds like to me that the 9 LEDs are cut from a 12v strip.
Each strip is designed to put 12v to every 3 LEDs at the cut line, so all 9 LEDs are tied together through the strip circuitry.
It looks like to me the the LEDs in the watch video are randomly flashing and not flickering (flickering sounds more like
the look of a flame).
.
Each strip is designed to put 12v to every 3 LEDs at the cut line, so all 9 LEDs are tied together through the strip circuitry.
It looks like to me the the LEDs in the watch video are randomly flashing and not flickering (flickering sounds more like
the look of a flame).
.
Heh. That was my guess, also. Sets of three corresponds to snip points on a 12V strip, and also agrees with the 8xAA pack the OP describes using for the lighting test. I'm not sure what a good term is for that kind of intermittent display -- I agree, "flicker" seems to imply intensity changes, just as "blink" implies a simple and regular repetition.
This seems to have stalled out. Pity. I was in fact offering to draft the board in Eagle, generate the BOM (pretty much have to, in order to get the Eagle files right), and order a prototype run of PCBs in order to confirm my design was correct. Not just for altruism; there are a couple of technologies here that are next on my list to explore as I refine my own LED circuits. I'd learn useful things putting together a self-powered board with surface-mount LEDs (and quite possibly MOSFET switches on them). Also a nice excuse to try out cut-trace solder jumpers.
propmaster2000
Sr Member
Not sure if this thread is still active, but I bought the Neopixel Ring and attached it to an ATtiny85 with it's own external 5v reg.
Here is a video where I loaded a red, white, blue, purple, green, orange with a variable pattern display code.
.
Here is a video where I loaded a red, white, blue, purple, green, orange with a variable pattern display code.
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propmaster2000
Sr Member
You know...we had some of those LED tea candles at Thanksgiving dinner. Not bright enough by themselves, but is practically a no-experience-required to chop out the LED, hang a power darlington in it's place (the venerable TIP120) and switch whatever arbitrary string/voltage is on the actual prop.
MythMaker
Active Member
Hey everybody - thanks for all the input! I was excited to try getting into adafruit and all that but realized I probably did not have the time to do it. The convention is coming up in about a month at this point, and I still have lots of work to do. A few weeks ago I remembered we had gotten a flickering/short circuit lightbulb for Halloween. I got out my dremel and cut it open (see pics). Unfortunately, when I tried hooking it up to the battery pack, nothing happened. Going to need some kind of adapter to make that work.
However, Nomuse, I'm IMing you to see what we're talking about here...
However, Nomuse, I'm IMing you to see what we're talking about here...
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MythMaker
Active Member
DUPLICATE DELETED Sorry
- - - Updated - - -
This looks cool, thanks for the link. Will look at this closer during the day, and will post some pics of the revised model I got.
- - - Updated - - -
This looks cool, thanks for the link. Will look at this closer during the day, and will post some pics of the revised model I got.
propmaster2000
Sr Member
Good morning MythMaker,
<snip>
The convention is coming up in about a month at this point, and I still have lots of work to do. A few weeks ago I remembered we had gotten a flickering/short circuit lightbulb for Halloween. I got out my dremel and cut it open (see pics). Unfortunately, when I tried hooking it up to the battery pack, nothing happened. Going to need some kind of adapter to make that work.
>snap<
Did you post a picture of the Halloween flicker light bulb you cut open?
Also, if your Halloween bulb was originally 120AC, you will have to find where in that circuit it was converted to low voltage DC
in order to drive the bulb LED's.
What convention are you planning for?
Have a good afternoon.
.
<snip>
The convention is coming up in about a month at this point, and I still have lots of work to do. A few weeks ago I remembered we had gotten a flickering/short circuit lightbulb for Halloween. I got out my dremel and cut it open (see pics). Unfortunately, when I tried hooking it up to the battery pack, nothing happened. Going to need some kind of adapter to make that work.
>snap<
Did you post a picture of the Halloween flicker light bulb you cut open?
Also, if your Halloween bulb was originally 120AC, you will have to find where in that circuit it was converted to low voltage DC
in order to drive the bulb LED's.
What convention are you planning for?
Have a good afternoon.
.
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MythMaker
Active Member
Doh! Edited previous post and insert the pics.
I'm going to try to figure out where the circuit converts current.
I am prepping for PAX South in January!
Replied in IM. Repeating here that for centralized control -- and working on a tight deadline -- the simplest option for you is probably Arduino and a MOSFET shield from Sparkfun -- https://www.sparkfun.com/products/10618 .
The Arduino's built-in regulator can handle 12V as long as you aren't drawing a lot of current for other things. And with the MOSFET shield all the heavy lifting is done on the shield. Biggest downside from your point of view is you'd need to learn the basics of Arduino programming, and also decipher Sparkfun's documentation.
The Arduino's built-in regulator can handle 12V as long as you aren't drawing a lot of current for other things. And with the MOSFET shield all the heavy lifting is done on the shield. Biggest downside from your point of view is you'd need to learn the basics of Arduino programming, and also decipher Sparkfun's documentation.
propmaster2000
Sr Member
MythMaker,
I see from your picture that there appears to be three main components.
LED panel, most likely the flicker circuit (under the shrink tube) and possibly the AC to DC converter.
Do you have a multi-meter?
Did the 120vAC go directly into the two short red,black wires of the first board
and is there a way for you to reconnect it to power again with clips without injury to yourself,
in order to take voltage measurements?
After looking at the board (with the small transformer), I do not see any Bridge Rectifier (or 4 diodes).
It is possible however that the AC to DC conversion is done on the board under the shrink tube.
You will have to remove the shrink tube to get a look under it and post a picture of both sides.
Is this the bulb you have:
.
I see from your picture that there appears to be three main components.
LED panel, most likely the flicker circuit (under the shrink tube) and possibly the AC to DC converter.
Do you have a multi-meter?
Did the 120vAC go directly into the two short red,black wires of the first board
and is there a way for you to reconnect it to power again with clips without injury to yourself,
in order to take voltage measurements?
After looking at the board (with the small transformer), I do not see any Bridge Rectifier (or 4 diodes).
It is possible however that the AC to DC conversion is done on the board under the shrink tube.
You will have to remove the shrink tube to get a look under it and post a picture of both sides.
Is this the bulb you have:
.
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I'd be uncertain of leveraging that 120 circuit. Those guys tend to work analog and do "clever" things with the precise characteristics of their circuit. I have one of those light-activated night lights in my bathroom converted to blue LED and I had to add an extra resistor to tweak the circuit to where it would actually turn off. Probably better to work "up"; start with a flicker candle and drive a Darlington switch (wasteful, but pretty near agnostic as to input and output which is why we still use them).
The reason I'm reaching for Arduino here is the meeting of time crunch and artistic goal. If you re-purpose someone else's flicker circuit you are stuck with the frequency and randomness they set. If you roll your own analog circuit, you are going to be spending a few hours trying different capacitor values and you are going to be constrained as to how nuanced you can get it. But once you get over the hurdle of code (and this is almost the simplest program you can write -- "blink" on the Arduino is literally four lines long and is the first example in the book) you can make it longer, more random, make double flashes, etc. Basically, you can make it duplicate what was visible on that game excerpt you linked to.
TLR; it's actually the shortest and most reliable way of doing it. And the reliably shortest as well; other methods may or may not work and you won't know until you've invested time you really don't have.
The reason I'm reaching for Arduino here is the meeting of time crunch and artistic goal. If you re-purpose someone else's flicker circuit you are stuck with the frequency and randomness they set. If you roll your own analog circuit, you are going to be spending a few hours trying different capacitor values and you are going to be constrained as to how nuanced you can get it. But once you get over the hurdle of code (and this is almost the simplest program you can write -- "blink" on the Arduino is literally four lines long and is the first example in the book) you can make it longer, more random, make double flashes, etc. Basically, you can make it duplicate what was visible on that game excerpt you linked to.
TL
R; it's actually the shortest and most reliable way of doing it. And the reliably shortest as well; other methods may or may not work and you won't know until you've invested time you really don't have.
MythMaker
Active Member
I don't have a multimeter.
That IS the bulb. Maybe I should cut the wires to the converter unit and try connecting the rest of it to the powerpack and see if thats all that is needed?
propmaster2000
Sr Member
Hi MythMaker,
Cut away the shrink tube and take a picture of the front and back, then post....
Thanks.
P.S. Seeing that there are 2 capacitors on the first board, there must be DC present.
You can try and put your "power pack" power on the red and black wire of the flasher circuit to see what it does.
You probably should cut away the first board however so it does not effect the circuit.
One other thing, is this circuit going to fit in your prop or are your LEDs going to be wired externally?
.
Cut away the shrink tube and take a picture of the front and back, then post....
Thanks.
P.S. Seeing that there are 2 capacitors on the first board, there must be DC present.
You can try and put your "power pack" power on the red and black wire of the flasher circuit to see what it does.
You probably should cut away the first board however so it does not effect the circuit.
One other thing, is this circuit going to fit in your prop or are your LEDs going to be wired externally?
.
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