I recently acquired an old 420ez flash unit. It's an older a-ttl flash unit but it is triggered by anything from 1.5 volts. Would anyone know if hooking this directly up to the arduino digital pins would be dangerous for it? What would be my best option. On MAKE recently someone used an optoisolator, but I am located in Russia and parts are hard to come by, would anyone else have any ideas?
hey
you could try this. the diode will provide voltage isolation...
Arduino output pin ---------|>|------><><><-------------><><><----- Arduino GND pin
diode 3K resistor F+ 2K resistor F-
This will put out 2V .
Connect the Arduino as above, and then connect the flash unit + input to the place where the two resistors meet (F+ above), and the - input to the Arduino ground (F- above). Use 1K resistors in series to make up the 2K and 3K values.
the diode can be any old diode- common numbers are 1N914 or 1N4148 or 1N4001 in North America.
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I recently acquired an old 420ez flash unit. It's an older a-ttl flash unit but it is triggered by anything from 1.5 volts. Would anyone know if hooking this directly up to the arduino digital pins would be dangerous for it? What would be my best option. On MAKE recently someone used an optoisolator, but I am located in Russia and parts are hard to come by, would anyone else have any ideas?
If you want the security of optical isolation but can't get a "regular" opto isolator, you can make your own with an LED, a phototransistor, and a piece of heat shrink tubing to hold it together and provide "dark."