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Author Topic: Triggering more than 1 OUTPUT pin at the same time  (Read 2338 times)
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NJ, US
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While nothing happens at precisely the same time, for the purposes of this project either method described above, either port manipulation (pins firing at same processor clock edge) or triggering all 3 flashes from the one pin would surely provide far more than the accuracy required though, yes?
Seems likely to me, but you'd need to know what the actual timing requirements were to know for sure. That was my point in saying that 'precisely the same moment' did not actually constitute a sensible requirement. But I still don't know what sort of timing accuracy the OP needs to achieve.

Sorry, I can't provide an exact number. All I know is that the flash duration is, on average, 1/35000 at 1/128th of power. Its very little light, so more than one flash is needed to illuminate the scene. I think the only way I'll know is when I actually shoot and see how its working... I'm def going to try the port manipulation approach as it makes the most sense to me...
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Dallas
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But I still don't know what sort of timing accuracy the OP needs to achieve.

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A canon 580ex II at 1/128 power has a duration of 1/35000 second. At 1/64 power its 1/30000 second.

Any overlap between the two flashes would be an excellent result.  The fastest flash is 1/35000 which is 28.6 microseconds.  (The number @AWOL posted earlier.)
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Croatia
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I stand corrected. 580 and 430 don't have optical slave capabilities (Canon, what the hell were you thinking??). Guess, it's back to arduino.
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I stand corrected. 580 and 430 don't have optical slave capabilities (Canon, what the hell were you thinking??). Guess, it's back to arduino.
Because both of them have wireless communications, rather than optical.
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A shift register would do the trick, for ya. You can trigger multiple pins at the exact same time.
https://www.sparkfun.com/products/733
From how I understand they work, is you set your pins to on or off via serial, then tell the register to output. So you say pin 1 on, pin 2 on, pin 3 off, pin 4 off... then say go, and it switches everything at the exact same time, for up to 8 outputs with this chip.
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