Not the first, but always nice to show some results XD Long exposures in dark room and triggered the flash on sound.
Used piezo for sound detection as in the trigger kit from the hiviz.com website. Hooked it up to my arduino to be abled to set the delay end reset time as I prefered. SCR to shortcut flash. Simple yet effective project.
Playing with different set-ups and delays (time between hard sound and flash trigger). Some results:
tried completing this project myself, can not seem to get the flash to fire. followed the diagram you have shown here.. i think it may be the scr, mind sharing the part number you used? or possibly any other thoughts as to what might case it?
I use an optocoupler with a lot of success, 2n35 I think. I'd think a SSR (Solid State Relay) would be overkill, but would work. Just remember older external flashes (and cheap new ones) sometimes dump a couple hundred volts or more across those terminals. An NPN transistor isn't enough.
What type of flash, by the way, and what mode? After a couple of paying gigs, I've finally actually purchased what might be considered my first "Professional" level hardware purchase, a Canon 430EX flash. First TTL flash I've had and I must say it's night and day (literally in some respects) in terms of managing exposure. I've not had time to "play" with it yet however, and I'm thinking that a TTL flash has to be ideal for stop motion- it quenches the strobe mid flash once appropriate lighting is sensed. That means very short duration if set up right, I would think.. I've already found that my Interfit (el cheapo) 150w/s heads just can't be used for stop-motion, the flash duration is far too long. They are great as a portable portrait setup, but those big tubes firing all that time.. motion blur when you are trying to avoid it.. painful.
Right now on my "to do" list is an idea you'll like: I have collected and am triggering TEN salvaged flash units from disposable 35mm cameras.. with variable, programmable, and triggered delays, driven by Arduino. Special Effects strobe that ought to be good for a ton of interesting effects....
if (meet == LOW){
delay(100); // delay between sound and flash
for (int value=0; value<255; value++) //Increase "Power" from output ~11 to Gate in SCR flash
digitalWrite(flashPin, HIGH); // flash goes off
digitalWrite(flashPin, LOW);
digitalWrite(ledPin, HIGH); // LED during 'dead time'
delay(4000); //to make sure I only get one flash
digitalWrite(ledPin, LOW);
}