The Shop > Electronics & IC Programing
Mad strobe?
vtsteam:
Thanks Andrew, I see. Well I was hoping for something either pre-built, cheap and available, or this other project cobbing together ordinary flash units and an arduino without too much circuit engineering/building. I think I actually already own a couple of hot shoe flashes from the old, and older days, and definitely have the arduino.
Maybe I'll plunk for the solid state relay unit, and try it out with my couple of flashes "just to see". Unless somebody has a better idea -- or warns me off of that relay.
Still curious if anybody knows how a hot shoe flash is triggered -- just a closed contact, or is is a voltage signal....?
vtsteam:
lookng at specs more closely, the solid state relay board has ssr modules rated for 100-240 V AC.
I need switches for DC at hot shoe signal levels -- as a guess 3V ?
I see some MOSFET boards available -- looking at MOSFETS like IRF520 -- would those be suitable?
joshagrady:
Do you need to have actual images of the arrow during its flight? It occurs to me that if you had some sort of baffles set up on either side of the "shooting range" (imagine a alleyway made up of walls of cardboard) than you could use an Arduino to record precise intervals of time as the arrow's flight triggered a series of either ultrasonic or IR sensors. Since you'd know ahead of time the distances at which the sensors had been placed, you could easily map the time difference between one trigger event and the next.
Or, you could open a whole different can of worms, and look into making a radar trap out of an old microwave.
I know that this video is not what you're looking for, but it is fairly on-topic:
Good to see you back.
--Josh
vtsteam:
Josh thanks. No it's not the arrow in flight I want to strobe-photo, it is the bow string on the arrow (in the nock), and the bow limbs, during the brief period before the arrow has left the bow.
This period of interest is about 1/60th of a second. And I'd like to divide it into 8 to 10 images so I can measure the acceleration of the arrow through the bow by measuring the distance the knock advances per frame.
I'm seeing some stroboscope projects on Instructables using LED arrays instead of the camera's usual flash tube. I'm wondering if they would prove bright enough. Here's one well documented project:
http://www.instructables.com/id/Stop-Time-with-an-LED-Stroboscope/
it uses a stamp instead of an arduino, and analog inputs for rate and pulse duration. I'd probably use an arduino and just program in the other parameters, so I could maybe simplify the circuit quite a bit. I'd only need one output channel instead of 8 to 10 with multiple flash strobes. The only question is whether the LED array would be bright enough.......
RobWilson:
No input from me :palm: , Just good to see you back Steve :thumbup:
Rob
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