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DIY Sound-Activated High-Speed Photography

Soulskill posted more than 3 years ago | from the point-and-pop-a-balloon dept.

Hardware Hacking 106

eldavojohn writes "Have you ever wanted to catch the perfect photo with your SLR camera but couldn't time the shot just right? Photography enthusiast Matt Richardson brings us an instructional video over at Make Magazine that shows how to use some very basic breadboarding and an Arduino Nano to do some high-speed flash photography that is timed by sound instead of your finger hitting the button on the camera. He pops a balloon and smashes a wine glass to show some results. His code is available on Github, and you can find more of this sly hardware hacker on his YouTube channel."

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106 comments

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OK (4, Insightful)

hjf (703092) | more than 3 years ago | (#34374798)

Seriously, why do we need an Arduino to make a sound trigger?

Oh yes, all the cool kids use arduinos now, so if you make an electronics project without one, no one is going to read your article.

Re:OK (1)

Eunuchswear (210685) | more than 3 years ago | (#34374840)

Yeah, I'd just whip up a bit of python,

Oh, you mean your camera doesn't run Linux. How odd.

Re:OK (2, Interesting)

OzPeter (195038) | more than 3 years ago | (#34374904)

Oh, you mean your camera doesn't run Linux. How odd

I used to have an HP dig cam that allowed you to write programs against a public API, that you could load into the camera via the CF card and then run from the camera.

Re:OK (1)

dargaud (518470) | more than 3 years ago | (#34379340)

I used to have an HP dig cam that allowed you to write programs against a public API, that you could load into the camera via the CF card and then run from the camera.

Huh, I'd piss my pants for something like that.. What model was it and are there still cameras like that ?!?

Re:OK (1)

thisisntme (1617485) | more than 3 years ago | (#34380362)

You can do that (unofficially) with many Canon cameras, have a look at CHDK

Re:OK (1)

OzPeter (195038) | more than 3 years ago | (#34374868)

Seriously, why do we need an Arduino to make a sound trigger?

Oh yes, all the cool kids use arduinos now, so if you make an electronics project without one, no one is going to read your article.

Well how about that the system:

  1. Shuts off the room lights
  2. Opens the camera's shutter
  3. Waits for the sound event
  4. Triggers the flash
  5. Closes the camera's shutter
  6. Turns the room lights back on

Try doing all of that with 74xx gates and see how long it takes you to debug it

Re:OK (1)

hjf (703092) | more than 3 years ago | (#34375536)

Yes. But this "system" just fires the flash. It doesnt do anything else.

Re:OK (2, Funny)

OzPeter (195038) | more than 3 years ago | (#34375736)

Yes. But this "system" just fires the flash. It doesnt do anything else.

Ummm .. You didn't watch the video did you?!?!!?

Re:OK (0, Flamebait)

hjf (703092) | more than 3 years ago | (#34375868)

I just skipped through it. Still, the only EXCITING thing it does is to turn off the lights. Still doesn't impress me. You know what would have impressed me?

If he could trigger Nikons (cheap models allow only "smart" USB triggering) [difficult one]. Also IR transmitter is OK.
If it had a pot to set the delay [stupid-easy]

Re:OK (1)

drolli (522659) | more than 3 years ago | (#34376126)

I personally would prefer a combination of 40xx. Should not take more than 3 ICs, and will work more reliably than the microcontroller, probably take less power and have wider voltage range in operating.

Re:OK (1)

LogarithmicSpiral (1463679) | more than 3 years ago | (#34374874)

In the video he said he knew the Arduino was unnecessary for the current task, but he planned on expanding the project. He also wanted to turn out the lights in the room.

Re:OK (1)

thegarbz (1787294) | more than 2 years ago | (#34385226)

So he's added one extra complexity and decided it is worth of requiring a 16MHz microcontroller rather than simply adding another transistor to do the job? It's like saying I need to walk to the train station but it's only slightly too far to walk. I know I'll buy a Ferrari for this commute.

What an epic waste of a microcontroller. He and you should turn in your geek card if you haven't figured out how to make this all USB controlled and coded up a computer interface within the afternoon.

Re:OK (1)

j00r0m4nc3r (959816) | more than 3 years ago | (#34374970)

Why do we need anything other than food, water, and a cave?

Re:OK (2, Funny)

Yvan256 (722131) | more than 3 years ago | (#34374986)

Food, water, a cave and high-speed internet.

Re:OK (1)

TheGratefulNet (143330) | more than 3 years ago | (#34375064)

All right, but apart from the sanitation, medicine, education, wine, public order, irrigation, roads, the fresh water system and public health, what have the Romans ever done for us?

Re:OK (1)

poetmatt (793785) | more than 3 years ago | (#34375296)

in plenty of situations, it appears like the education part was left out

Re:OK (0, Flamebait)

GNUALMAFUERTE (697061) | more than 3 years ago | (#34375932)

Some really bad things, namely: Lawyers and Christians.

Re:OK (1)

Kilrah_il (1692978) | more than 3 years ago | (#34376738)

Brought peace?

Re:OK (1)

gmhowell (26755) | more than 2 years ago | (#34385538)

The quality of replies indicates the sad state of affairs that most slashdotters are unfamiliar with the greatest movie ever financed by a former Beatle.

Re:OK (1)

mangu (126918) | more than 3 years ago | (#34376092)

Food, water, a cave, high-speed internet, and hookers.

Re:OK (1)

Yvan256 (722131) | more than 3 years ago | (#34376228)

Food, water, a cave, high-speed internet, blackjack and hookers.

Re:OK (1)

falzer (224563) | more than 3 years ago | (#34376308)

In fact, forget the food, water, cave, high-speed internet, and blackjack!

Re:OK (2, Insightful)

JustinOpinion (1246824) | more than 3 years ago | (#34375060)

Well an Arduino would not be the right choice if you were building a large run of a commercial product. But we're talking about DIY here. The advantage of using something more powerful and general purpose like an Arduino is:
1. Easier to rapidly prototype, tweak your setup, or add features. (It's faster to re-code your Arduino than to rewire some electronics you soldered.) You can increase the scope/complexity of your project quite easily.
2. If you're already familiar with the Arduino, and have one on-hand, it's faster/easier/cheaper to use that. (Again, not everyone has a box of Arduinos, but the DIY-ers that this tutorial is aimed at may very well have some on-hand.)
3. When you're done with this project, you can remove the Arduino and re-purpose it easily.

Obviously you can make a cheaper/faster/more-efficient sound trigger using equipment more basic and specialized than an Arduino. (You can also build far better toys using dedicated materials rather than Legos.) For playful building/testing/etc. using an Arduino is quite useful. And, yes, there is an advantage to a DIY community ("all the cool kids") settling on a common set of general-purpose tools, since it lets them exchange design plans, code, experience, etc.

Re:OK (0, Flamebait)

hjf (703092) | more than 3 years ago | (#34375566)

The guy is just another youtube-star-wannabe douche. If you want to make a "tutorial" do it for something real, not a quick and dirty prototype.

Re:OK (1)

sznupi (719324) | more than 3 years ago | (#34376174)

...recreating something done closer to XIX than to XXI century. Very much DIY back then, too.

Re:OK (1)

noidentity (188756) | more than 3 years ago | (#34375122)

Are you suggesting that one should use discrete components, or that any microcontroller would do? Since all the cool kids are using them, it means the dev tools are decent and tutorials and examples are plentiful, thus it's a good idea to use one. See x86, Windows, PC architecture for examples. At least they didn't plaster Arduino into the headline.

Re:OK (2, Interesting)

hjf (703092) | more than 3 years ago | (#34375598)

Discrete components. Google for "sound trigger" and you'll see how easy it is to build one out of an opamp or even 2 transistors and a few resistors.

Re:OK (1)

falzer (224563) | more than 3 years ago | (#34375170)

I'd have just used an 8 bit micro because it's cheap and minimizes parts, just not an Arduino because I don't use Arduinos.

Think of it this way: you can be glad it was done with a "coder friendly" AVR platform rather than some beast of a processor running Java on Linux with breakneck 10ms latency.

Re:OK (2, Interesting)

Caradoc (15903) | more than 3 years ago | (#34375208)

Seriously, why do we need an Arduino to make a sound trigger?

I agree that the Arduino is overkill for a basic sound trigger - but projects like the Camera Axe [cameraaxe.com] make a lot more sense. I use a variation on the Camera Axe for photographs of lightning among other things.

Re:Trigger the Arduino (1)

Announcer (816755) | more than 3 years ago | (#34375720)

I'm surprised the piezo had enough output, without amplification, to trigger the chip.

Re:OK (4, Interesting)

Technician (215283) | more than 3 years ago | (#34375818)

I did this in the 1970's for a photography project using an SCR to handle the high strobe trigger voltage (used to be ~160 volts on the shutter contacts) and the amplifier from a portable tape recorder to amplify a microphone to enough voltage to trip the SCR. With a strobe mounted off the camera and the camera on bulb setting, I took pictures of light bulbs crashing onto the sidewalk. Due to the lighting angle, most people thought it was taken in the daytime in sunlight. I adjusted the delay after impact by changing the distance of the mic from the bulb. 6 feet provides a good delay. With the mic too close, the bulb looks like it is sitting on the sidewalk with a few cracks in the glass. The delay was necessary to get the bulb in a reasonable amount of shards.

Re:OK (1)

thegarbz (1787294) | more than 2 years ago | (#34385164)

I did this in 2004 for a photography project using 4 transistors a few resistors, microphone and battery. These days flash triggers are low voltage. The SCRs were necessary back then, but seriously what is it with people throwing a 16MHz microcontroller and code to run it at something that can be made with a tiny handful of discrete components.

Re:OK (1)

Announcer (816755) | more than 2 years ago | (#34385398)

That sounds a lot like the "Thunderbolt" article I read in the magazine. Nice job!

Re:OK (1)

nametaken (610866) | more than 3 years ago | (#34376220)

I'd guess because people are familiar with them.

But you should hop on there and show us how to make one without the expensive Arduino! Lots of us out there can follow instructions, and learn a little in the process, but wouldn't know how to make our own from scratch. :)

Re:OK (2, Insightful)

Eil (82413) | more than 3 years ago | (#34376398)

Because otherwise there wouldn't be anyone to complain about it on Slashdot? Do you read your email in pine over a serial terminal too?

The photographer had minimal electronics experience and simply used what knowledge and equipment he already had on-hand to create a useful hack. The great thing about Arduino is that it's flexible and simple. It allows people to slap together all manner of interesting projects without the benefit of an electronics engineering degree. In fact, it was explicitly designed as a way for artists and non-geeky folks to add basic electronic features to their projects. So what if it's overkill for a purpose like this? For the hobbyist, one Arduino board beats having to stock dozens of common single-purpose ICs.

Re:OK (1)

Gordonjcp (186804) | more than 3 years ago | (#34376524)

Somewhere in a box here I have a copy of Hobby Electronics from the early 1980s, which has a sound-triggered flash sync unit. If I recall correctly, it used a couple of opamps as a mike amplifier/filter and a comparator, and an SCR to actually trigger the flash.

It's a shame there aren't any pictures, or any description of how it actually works. It would have been nice to see his results.

Re:OK (1)

NoMaster (142776) | more than 2 years ago | (#34385734)

Hell, somewhere in a box here I've got a reprint of an old Gernsback magazine from the 50's which has a sound-triggered flash unit with delay. It uses a single valve as a class C amp (to give an adjustable threshold & immunity from background noise), a longish-timebase switchable R-C filter as an adjustable delay, and another single valve output stage to drive (IIRC) a B-C flash.

Also, didn't Doc Egerton publish the schematics of his strobes (not the same thing, admittedly, but close) back in the 30's?

I guess the point of both of our comments is that this sort of thing was "News for Nerds" 50 or more years ago. Today, not so much...

Re:OK (2, Interesting)

bill_mcgonigle (4333) | more than 3 years ago | (#34378154)

Seriously, why do we need an Arduino to make a sound trigger?

To generalize your question:

Why do we need an Arduino to ___________?

I'll take a stab at it: Because it allows a software developer to do things that previously required a hardware developer (EE), for certain problems. This unbinds prototyping from a certain educational requirement, opening the field to more participants. For one-off projects of value, the cost of an Arduino board may be low enough to be considered negligible.

It's exceedingly doubtful anybody would go into mass-production with an Arduino-based design, unless time-to-market or field upgradability were the ultimate criteria, or the volumes were low enough that hiring proper engineering would not be cost effective.

Quicker Than Sound (1)

Thelasko (1196535) | more than 3 years ago | (#34374890)

Seeing how light travels much faster than sound, my initial reaction is that this is a terrible idea.

Re:Quicker Than Sound (0)

Anonymous Coward | more than 3 years ago | (#34374926)

You sure could make a light-activated trigger to capture explosions, flares and other events that cause a rapidly appearing bright light. But you won't easily catch a breaking baloon or shattering glass that way, because they cause noise, but not flash.

Re:Quicker Than Sound (2, Informative)

djlemma (1053860) | more than 3 years ago | (#34375186)

Also, the thing about this type of high speed photography is that you're triggering the light source... so if you're trying to photograph something that creates its own light, these strobe-triggering devices are going to do you no good at all.

To do that, you'd need to trigger a high speed shutter, which is a lot harder to do.. there's usually a lag between when a shutter is triggered and when it actually takes a picture, and the mechanical shutters on most SLR's don't actually go much faster than 1/250s. The images you see of matches being struck and explosions happening and such are taken with motion picture cameras with very high framerates.

Although, with electronic shutters that are becoming more common, there might be a way to get actual shutter speeds of 1/8000s with minimal lag. Could be very cool.

Re:Quicker Than Sound (1)

Neil Boekend (1854906) | more than 2 years ago | (#34386122)

An LCD cover over your lens may be perfect.
The power triggered by an LDR or light dependent diode via a comparator. Maybe a capacitor and a potmeter somewhere to set the shutter time. Set the trigger up so it is default ON.
The LCD cover could theoretically be taken from some 3d shutter glasses (preferably glasses which have been mauled by a dog/crushed by a behind, but with one glass intact)

Re:Quicker Than Sound (2, Insightful)

bucaneer (1594601) | more than 3 years ago | (#34374996)

Real life, macroscopic events (i.e. stuff you'd want to photograph) happen at speeds that are closer to the speed of sound rather than that of light, so catching the very first wave of photons probably would not be very useful practically, not to mention insanely more difficult.

Re:Quicker Than Sound (0)

Anonymous Coward | more than 3 years ago | (#34375050)

To the parent's point, the first thing that came to mind for me was attempting to catch a lightning strike. Seems like it depends heavily on what you want to catch and how far away it is in order for this trigger to be useful.

Re:Quicker Than Sound (0)

Anonymous Coward | more than 3 years ago | (#34375258)

Conveniently, you don't need a flash to see lightning, so you don't need a trigger like this at all. Just set your camera up with a manual bulb, avoid ambient light as much as possible and point it at your anticipated lightning.

Then open the shutter, after you see the lightning yourself, close the shutter.

The less time between open and close (ie if you can guess when the lightning is coming) the better as you'll get less ambient light polluting your shot.

Done

Re:Quicker Than Sound (2, Informative)

djlemma (1053860) | more than 3 years ago | (#34375406)

Even better... Just open your camera's shutter and put your hand in front of the lens until you see a lightning strike beginning. Remove your hand for just the amount of time that you see lightning. Then, put your hand back without closing the shutter. Repeat for however long you want to leave the shutter open, say 30 seconds. If you capture a few lightning bolts this way, you end up with a shot that looks like Zeus was VERY angry.

Re:Quicker Than Sound (5, Funny)

lee1 (219161) | more than 3 years ago | (#34375786)

You don't need a flash for fireworks either. So why am I surrounded by people taking flash pictures of the sky whenever I go to a fireworks show? So far I have been able to resist grabbing them by their collars and screaming at them, but I'm not sure how long I can hold out.

Re:Quicker Than Sound (1)

SmlFreshwaterBuffalo (608664) | more than 3 years ago | (#34376102)

So far I have been able to resist grabbing them by their collars and screaming at them...

Then you, sir, are a better man than I.

...It sure was nice of them not to press charges that night, though.

Re:Quicker Than Sound (1)

mangu (126918) | more than 3 years ago | (#34376164)

So why am I surrounded by people taking flash pictures of the sky whenever I go to a fireworks show?

Because they have crappy point-and-shoot cameras that trigger the flash automatically whenever the light that reaches the lens falls below a certain level.

Re:Quicker Than Sound (1)

brainboyz (114458) | more than 3 years ago | (#34376222)

Some people don't know how to turn the flash off, or don't want to go through the trouble of switching modes when taking sky pictures vs. near-object (friends at the show) pictures.

Re:Quicker Than Sound (-1, Redundant)

Anonymous Coward | more than 3 years ago | (#34376790)

They aren't taking flash pictures, their cameras are. Most people probably have no idea when a flash is needed and when it's not. But there's nothing they could do about it anyway, because most of those cameras are point and shoot.

Re:Quicker Than Sound (2, Informative)

johnlcallaway (165670) | more than 3 years ago | (#34377822)

Taking photos of lightening at night is very doable using this method. But not when you are trying to take some of the most beautiful lighting pictures ... which occur during the day. Using your reflexes to time shutter open/close is more luck than skill. Even at night, depending on the dSLR camera, the amount of time it takes for the camera to process a bulb setting and store the image can introduce long delays between shots, and missed opportunities. Bulb settings increase the noise in a shot the longer the shutter is open. Turning off the camera noise processor and doing it in Photoshop reduces in-camera processing time significantly, but it can introduce odd bits of color scattered around the photograph that require touchup.

That's why they sell lightening triggers that use the lightening flash itself to trigger the shutter. Camera lag is an issue, but not with the higher end cameras.

I only use the nighttime long-exposure method as the lightening triggers are a little pricey for my taste.

Re:Quicker Than Sound (1)

Caradoc (15903) | more than 3 years ago | (#34375310)

Using a sound trigger to capture lightning strikes is counterproductive. Using an IR sensor to measure the ambient IR, then trip the shutter when the IR spikes up works a treat, though. I built a variation on the Camera Axe [cameraaxe.com] last summer, and have been using it to take daylight photos of lightning strikes like this one [flickr.com] .

Re:Quicker Than Sound (1)

Carnildo (712617) | more than 3 years ago | (#34381466)

I just used a cable release and a camera in "bulb" mode. Point the camera in the general direction of the storm, hold the shutter open for 15 seconds or until you get a good lightning strike, repeat. For daytime work, add a neutral density filter and reduce the exposure time.

Re:Quicker Than Sound (1)

socsoc (1116769) | more than 3 years ago | (#34375028)

If you're close to the object, wouldn't the difference in speed be negligible?

Re:Quicker Than Sound (1)

SlamMan (221834) | more than 3 years ago | (#34375034)

Sure, but at a distance of a couple yards, it's not going to make a difference. Anybody want to back that up my claim with some math?

Re:Quicker Than Sound (1)

xaxa (988988) | more than 3 years ago | (#34375246)

Just Google it [google.co.uk] :-)

6ms isn't very long, but we're back into the real world for estimating how far the balloon will have moved in that time, so someone else can take over.

Re:Quicker Than Sound (2, Informative)

Monkeedude1212 (1560403) | more than 3 years ago | (#34375570)

6ms is long enough for something (like a balloon starting to pop) to happen.

Most people, if they try hard enough, can count to 10 aloud in 1 second. That means they are speaking with the capable thought around 100ms. Now, just imagine how high you can count in your mind, not speaking aloud, in 1 second. How many instant thoughts can you get? How many milliseconds is it to process the next number in your counting scheme for you?

Now try watching a baloon pop. Try capturing that moment where the shape is Juuuuust starting to rupture - even though it's no longer holding the air in. How fast do you think that went? It wasn't like 1ms, but it wasn't 100 either.

The big thing to consider is the technically difficult issue of trying to get the baloon to pop and take a picture based on "Light" - something I think the GP completely overlooked. The reason we use sound is because its easy to set up a trigger for that - because the trigger is actually the baloon popping, not our own specific timer. A baloon doesn't produce a flash of light when it pops - so you can't use light to set off your photo, unless you are trying to detect the difference in shape of the baloon on a really tiny scale and hope it sets off your radar triggers or something incredibly complex - because simply timing the photo with your needle doesn't always work.

Sound is simply the simplest way.

Re:Quicker Than Sound (2, Interesting)

pz (113803) | more than 3 years ago | (#34375262)

Seeing how light travels much faster than sound, my initial reaction is that this is a terrible idea.

Didn't bother viewing the linked video, eh?

The idea works pretty well because things with mass tend to move slowly, so despite the latencies involved and differential speed of sound and light, the described mixed digital / analog device works quite well to capture a mid-pop baloon or breaking wine glass. But then there are all of those classic Doc Edgerton photos that were taken with just analog circuitry, and they worked fine, too. Indeed, Prof. Edgerton made quite a career for himself at MIT using just this idea. So, despite the perhaps 10 seconds of thought you put into the problem before composing your negative reply, the idea has merit.

Re:Quicker Than Sound (0)

Anonymous Coward | more than 3 years ago | (#34375468)

That's just a matter of where you put the microphone.

Re:Quicker Than Sound (1)

djlemma (1053860) | more than 3 years ago | (#34375624)

For pretty much anything happening high-speed, you want to take your photo slightly after whatever triggering event happens. If you're firing a gun, you want to see the bullet exiting the chamber, not the initial loud explosion when the hammer hits the bullet inside the gun. With a glass shattering, you want to see shards and fragments suspended in mid-air with a hammer partially through the glass, not the initial impact of the hammer before the glass has broken up.

So, basically, with a sound trigger or a light trigger (say an infra-red beam hitting a sensor, or something like that) you're still going to want a delay before the strobe is fired.

The hell? (1, Informative)

Anonymous Coward | more than 3 years ago | (#34374974)

Why is that worthy of a Slashdot submi... OMG ARDUINO, WOOT!

Get a Canon with CHDK (1)

NtwoO (517588) | more than 3 years ago | (#34375038)

A large portion of the canon cameras support CHDK (canon hack devkit). One of the nice features included in this is motion detection. This requires no external components to get it working, as it uses the CCD for triggering. There are numerous scripts that use CHDK to implement delays, time laps photo sequences or other funky actions. Most of the supported cameras are fast enough to capture lightning.

Re:Get a Canon with CHDK (1)

Xelios (822510) | more than 3 years ago | (#34375204)

I've tried this, it actually works really well for photographing lightning. The only downside is the motion detection script eats up batteries like nobody's business.

Re:Get a Canon with CHDK (1)

the_other_chewey (1119125) | more than 3 years ago | (#34377844)

A large portion of the canon cameras support CHDK (canon hack devkit).

Just as a minor nitpick about nomenclature: No they don't.
CHDK supports the cameras, not the other way around.

And yeah, playing with it is really fun.

I saw this done in the 70's! (4, Interesting)

Announcer (816755) | more than 3 years ago | (#34375076)

Back then, a similar project used op amps to trigger a flash unit. It was an article in one of the electronics mags I saw back in the late 1970's, titled "Build the Thunderbolt". (I Googled it, but came up empty.)

You adjusted the timing of when the flash was triggered, by moving the microphone closer or farther from the sound source. You could also have added a 555 timer, if you needed a longer delay than was feasible with a longer distance.

It reminds me of a discussion at the Electronics firm I am consulting for. They needed to add a 1/2 second delay to the startup of a device in a new product. I suggested they add a 555 timer circuit. They looked at me like I had two heads. Their solution was to throw a microcontroller into the product. Come on, guys! It can be done with a 555, a cap, and two resistors. It's crash-proof, too. Whatever happened to K.I.S.S?

Re:I saw this done in the 70's! (1)

radtea (464814) | more than 3 years ago | (#34375254)

Whatever happened to K.I.S.S?

No money in it.

Re:I saw this done in the 70's! (1)

Arlet (29997) | more than 3 years ago | (#34375516)

Whatever happened to K.I.S.S

If you already have microcontroller, and know how to use it, it may be simpler than a 555. With most microcontrollers you won't need any external parts, and you can easily adjust the timing.

Re:555 vs MCU (1)

Announcer (816755) | more than 3 years ago | (#34375692)

They were talking about *adding* a micro to a mostly analog product. A 555 with the C and two R's would actually be cheaper. It was not meant to add features or function, *only* a .5 sec delay.

Re:555 vs MCU (1)

Arlet (29997) | more than 3 years ago | (#34377328)

Of course, it all depends, and I've not seen your design, so it could be that a 555 is simpler. In other cases, a microcontroller may be simpler. What's cheaper also depends on the circumstances. Price at digi-key for a NE555 from TI is 29 cents, while their cheapest microcontroller (PIC10F200) is only 34 cents (both @ 100 pieces). The microcontroller also comes in SOT23-6, so it takes up less board space, not even including the C and Rs. And maybe the microcontroller, in the same circuit, can also replace some other functions as well.

Re:I saw this done in the 70's! (1)

asvravi (1236558) | more than 3 years ago | (#34375780)

Come on, guys! It can be done with a 555, a cap, and two resistors.

A 555, a cap and ONE resistor if all you need is a monoshot as in this application.

Re:I saw this done in the 70's! (1)

mangu (126918) | more than 3 years ago | (#34376326)

I suggested they add a 555 timer circuit. They looked at me like I had two heads. Their solution was to throw a microcontroller into the product. Come on, guys! It can be done with a 555, a cap, and two resistors. It's crash-proof, too. Whatever happened to K.I.S.S?

A PIC like the 12F675 has eight pins, like the 555, and needs no external components at all. What can be simpler than that?

After I got a 100-pack of 12F675s at a special discount price I decided never to use a 555 again.

Re:PIC vs 555 (1)

Announcer (816755) | more than 3 years ago | (#34377664)

Multiply it by thousands. Those chips all have to be flashed and tested. That's time & money. With the R and C, the 555 just works, out-of-box. Crash-proof, foolproof.

Re:PIC vs 555 (1)

mangu (126918) | more than 3 years ago | (#34380294)

Multiply it by thousands and those capacitors and resistors begin to add up, multiply it by millions and the printed circuit real estate plus solder needed for the passive components start having a price impact. Flashing and testing a PIC takes less time than inserting, clipping leads, and soldering a couple of components.

Anyhow, when was the last time you needed just a half-second delay and nothing else from a circuit? With a PIC, the connections are the limit. From six pins in an 8-pin DIP to 40+ or more from the bigger packages, you cover a vast range of applications.

The only thing I really don't like about current PICs is the programming. I dream of an age, hopefully not too far away, when there will exist 8 pin PICs that cost less than a dollar running Linux and programmed in Python.

Re:PIC vs 555 (1)

Announcer (816755) | more than 2 years ago | (#34384232)

The units being made are all surface-mount. No insertion or drilling or clipping. There are already dozens of parts. The "real estate" is a non-issue, as there is PLENTY of room on the board. This device was already developed, and testing was being done on a few production prototypes, when the need for a brief delay was noticed.

In this application, there is absolutely no question that the 555 would be the MUCH better choice.

Cool -if you add an arduino (1)

formfeed (703859) | more than 3 years ago | (#34376546)

And then you could have an arduino with one of the analog output pins changing the R value in the 555 delay loop? Right?
Dude, that would be awesome!

Re:I saw this done in the 70's! (1)

DerekLyons (302214) | more than 3 years ago | (#34376606)

It reminds me of a discussion at the Electronics firm I am consulting for. They needed to add a 1/2 second delay to the startup of a device in a new product. I suggested they add a 555 timer circuit. They looked at me like I had two heads. Their solution was to throw a microcontroller into the product. Come on, guys! It can be done with a 555, a cap, and two resistors. It's crash-proof, too. Whatever happened to K.I.S.S?

K.I.S.S. operates on many levels. Maybe they already use the microcontroller elsewhere, so it makes sense to use components already on hand. Maybe the microcontroller is compatible with the power available inside the device and the 555 isn't. Maybe it's simpler for their assembly machines to handle the microcontroller rather than a 555 and it's associated components...
 
Without more details. it's hard to judge - but K.I.S.S. is a principle to be applied intelligently within the range of constraints on the design, not a mindless bromide to be followed as dogma.

Re:I saw this done in the 70's! (0)

Anonymous Coward | more than 3 years ago | (#34377654)

did you even read his post?

> Their solution was to throw a microcontroller into the product.

Re:Throwing a MCU into a product (1)

Announcer (816755) | more than 3 years ago | (#34377838)

Reiterating - this is a mostly analog product. It does not already have or need an MCU.

They were thinking of throwing one in, *ONLY* to add a .5 sec power-on delay. There are other chips dedicated to this same function, but the 555 is universal. (Or, at least, it USED to be.) 3 parts; the IC, a cap and a resistor. No need to flash and test. Piece of cake for most assembly houses.

The MCU would require at least a crystal or some other clock. There is also the potential for some RFI being generated, or the MCU locking-up due to RF exposure. (This product is meant to be used in an RF-rich environment.)

Re:Throwing a MCU into a product (1)

DerekLyons (302214) | more than 3 years ago | (#34382296)

Reiterating - this is a mostly analog product. It does not already have or need an MCU.

That's not reiterating, as that wasn't in your original message. It's adding additional details after the fact. Details that are utterly irrelevant to the design principles I enumerated in my message. This, along with the balance of your reply, shows you can't tell the difference between design principles and blind dogma
 

the 555 is universal. (Or, at least, it USED to be.)

I would expect an intelligent consultant to know whether or not it CURRENTLY is universal - that it used to be is utterly irrelevant. Again, you advocate blind dogma over knowledge.
 
I'm sure glad I no longer hire consultants - I encountered too many just like you.

Re:Throwing a MCU into a product (1)

Announcer (816755) | more than 2 years ago | (#34384400)

It *is* a reiteration, because in my original post, I said, "Their solution was to throw a microcontroller into the product."

This implies the following:

1) This product does NOT already have one.
2) It was being inserted for no other purpose than a .5 sec delay.

I think you missed that.

It is pure assumption on your part, to say that I am spouting some kind of "dogma". What "dogma", pray-tell? That using a common, inexpensive, very reliable, simple device is better than a highly sophisticated (comparatively speaking) microcontroller?

The 555 is a mature technology, with very well-known characteristics. It is also very stable. This product is intended to be used in an RF-rich environment. The MCU generates, and could be susceptible to, RF energy. This could be a problem.

There also could be occasional noise on the power supply feeding the product. This would only cause the 555 to recycle, thus reinitializing the product, but an MCU could lock up. If MCU were to lock up, that would force the user to power-cycle it. The 555 wins for these reasons. Nothing "dogmatic" about that. It's common sense.

You've formed a very negative opinion of me, my experience, and my integrity, based upon very little information. I hope this additional information has clarified why I said what I said. In all honesty, I didn't think it would have been necessary to go into such detail. Maybe next time, I should just post their schematic... no, I think not.

Re:Throwing a MCU into a product (1)

Muad'Dave (255648) | more than 2 years ago | (#34390830)

Not to disagree, but most PICs have internal oscillators these days.

Re:Throwing a MCU into a product (1)

Announcer (816755) | more than 2 years ago | (#34391618)

That's fine... but it is still a source of RF, and could still be susceptible to the effects of external RF.

Re:I saw this done in the 70's! (1)

aiht (1017790) | more than 2 years ago | (#34384006)

Without more details. it's hard to judge

So why are you judging?
Announcer already has more details. Let them judge.

Re:I saw this done in the 70's! (1)

thegarbz (1787294) | more than 2 years ago | (#34385188)

For a startup delay I would have been looking at you like that as well. A 555 is fantastic for cyclical events, but for a one shot delay why not use a simple transistor and RC circuit? The use of a 555 which contains 28 transistors is overkill. What ever happened to K.I.S.S? :-)

Just taking a dig at you, I do not know the full details and sure a 555 may have been the best implementation. But seriously the K.I.S.S principle died when electrical engineers started being taught computer systems engineering rather than analogue circuitry. There's petty few electrical engineers out there who could even draw a model of a transistor let alone figure out the time constant of an RC circuit without googling.

To use 555 or not to... that is the ? (1)

Announcer (816755) | more than 2 years ago | (#34385364)

The place I worked for was very much analog. My former boss worked for CBS Labs, and was absolutely amazing. He could design almost anything using op amps! I assisted with the design of a number of nice little products.

That company I worked for was bought by another that specialized exclusively in CPU-based devices. Gobbling-up a product line that is 99% analog has proven to be quite the paradigm shift for them, so I have been consulting and providing tech support to their staff for a while, now. I like them, they are good people, and are good at what they do. I am learning from them even as they are learning from me. :)

Sure, you CAN use a CPU, but why, when a basic analog device will do the same job? CPU's can crash. Code can have bugs that crop up. CPU's tend to generate radio frequency noise, and can be susceptible to nearby radio transmitters. (This happens to be an important factor with many of this company's analog products.)

Barring physical component failure, an R/C time constant just works. Every time. Use analog for what it is best at. Why not use CPU's for what they are best at: Computation, decision-making, and automation? Marry the two when needed.

We had a product that used a PIC and analog together very nicely. An elegant little device. It was designed before my time there, but I helped to redesign and improve the analog circuitry quite significantly. That redesign has already proven itself in a drastic reduction in the number of returned products. Can't argue with success! :)

Re:I saw this done in the 70's! (1)

Muad'Dave (255648) | more than 2 years ago | (#34390806)

You don't even need the 555 if the delay signal consumer can stand a slow voltage ramp w/o oscillating. A simple RC circuit w/ a time constant of 500mS would work. The 555 adds a nice Schmitt trigger, of course.

Re:I saw this done in the 70's! (1)

Announcer (816755) | more than 2 years ago | (#34391582)

I don't know too many IC's that "like" having their power ramped up slowly, thus the 555 ckt.

Re:I saw this done in the 70's! (1)

Muad'Dave (255648) | more than 2 years ago | (#34391784)

Ironically, the RESET pin of most PICs have a Schmitt trigger on their input for just this case. If the input if a set/reset flip-flop or some other latching input, the quality of the signal doesn't matter that much. If it's a CMOS input or mosfet gate, then yeah, the 555 makes sense (or a discrete Schmitt or FF).

I first read.. (1)

gvoima (1868430) | more than 3 years ago | (#34375146)

DIY Sound-Activated High-Speed Pornography, but got utterly disappointed by the fact he used Arduino :(

sound is slow and late (1)

Strange Ranger (454494) | more than 3 years ago | (#34375172)

This is a cool proof of concept and neat little hack. But sound really isn't the best way to do high speed photography.
Look at the balloon in the video, you see the end of the action. I think ideally we want to see the moment the pin pricks it. Same with the glass, we want to see the hammer smashing it, not the moment after when the pieces are falling.
 
The CHDK [wikia.com] has been around for awhile and can produce flash sync at least up to 1/60,000th of second [wikia.com] on some pretty cheap cameras.
 
Simpler, if you don't like hacking your firmware, with high end flash heads you can simply use high speed sync mode and shoot around 8 fps at up 1/8000th of a second. Experimenting with wide apertures and higher (but still perfectly good)ISOs you can do pretty amazing things. Especially with the latest off-the-shelf radio strobe controls. You might have to work a little to catch the absolute perfect moment, but that's usually not hard with the right setup. TFA is a neat hack, but probably not the best nor the most direct route to great high speed photography.

need for copylefted educational photos (3, Interesting)

bcrowell (177657) | more than 3 years ago | (#34375298)

For a long time, the famous Edgerton photos [google.com] were a staple of physics textbooks. E.g., you could see the (huge) deformation of a tennis ball being hit by a racket. But the Edgerton images are all copyrighted, and it would be really helpful to have CC-BY-SA-compatible photos that could be used instead in places like Wikipedia. I'm the author of some copylefted physics textbooks, and I really haven't been able to find much that's useful. There's this [wikimedia.org] category on wikimedia commons, but there's currently not much in it that's useful educationally. IMO there are a couple of things that would be useful in physics education: (1) an image like the tennis racket, showing how an object's center of mass accelerates even while it's in contact with another object; (2) an image like the bullet going through the apple, which I believe shows that the speed of sound in the apple is less than the speed of the bullet.

The coolest image (1)

jovius (974690) | more than 3 years ago | (#34375378)

The guy should smash his own head. That would be cool. Should make a great meme too!

High School project (1)

JerryQ (923802) | more than 3 years ago | (#34375402)

In 1973 I had a tobacco tin, a bent piece of foil and a strobe light, airgun and camera. shutter open, fire airgun, shockwave completes circuit, strobe backlights pellet. trial and error found the right spot. The next one I did was a flicker photometer, but it was cool being allowed to bring an airgun into school. Jerry

min0s 2, Troll) (-1, Troll)

Anonymous Coward | more than 3 years ago | (#34375448)

con7ir8ing the [goat.cx]

Monday morning blues.. (-1, Redundant)

Anonymous Coward | more than 3 years ago | (#34375850)

I read that as "DIY Sound-Activated High-Speed P0rn0graphy" - every other word sound supremely intersting - DIY, Sound-Activated, High-Speed.

Re:Monday morning blues.. (1)

lxs (131946) | more than 3 years ago | (#34376086)

You mean like this [dangerousminds.net] ?

High-Speed? (1)

Arancaytar (966377) | more than 3 years ago | (#34377948)

How is making a noise faster than clicking a button would be?

Re:High-Speed? (1)

wed128 (722152) | more than 3 years ago | (#34380768)

It times easier if you're trying to photograph a gunshot or some such thing.

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