Hey everyone,
It's been a while since I last did anything that was electronics related, and that was way before the age of Arduino boards. I'm designing something that requires a short in a circuit upon command in order to trigger a camera flash. Is there any way to safely short the circuit to fire the flash without damaging the Arduino Uno board? If needed, I can elaborate a little more once I get home, and I can include some photos.
Thanks in advanced!
With kind regards,
Corbin
You can use a relay to supply a dry contact as an output.
The Arduino picks the relay circuit as needed.
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This has been done before.
Enter something like "camera shutter control" in the search box on top of this page.
I think opto couplers have been used.
Leo..
You need to be very careful which flash you are working with. Some of the older flash units had several hundred volts on the flash trigger connection - in the old 35mm cameras, they used a mechanical contact to fire it, so there was no problem, but with the newer electronic cameras, some of those old flashes can fry the newer camera trigger circuits. The one I am familiar with was the Vivitar 285 - there are two (or more) versions out there. HERE is some information on what to look for and how to check the trigger voltage. A Google search for "flash trigger voltage" turns up additional information, but it is something to be aware of.
Thanks everyone! I'll be connecting an electronic flash. I'll search the forums like suggested; I didn't realize this would be a common topic. I'm going to mess with a 5V relay. Cross Roads, thanks a ton for that schematic!
Electronic does not mean much 
It might help if you post the make and model of the flash. Although probably not complete, you can consult strobe trigger voltages for older flashes.
