Hi everyone,
I'd like to use my Arduino Uno as a remote to release the shutter on my IXUS 75 camera. The camera is currently running the CHDK firmware and I've made a USB remote to take pictures.
The remote uses a switch, 3 AA batteries in series (around 4.5v) and a USB port which the camera plugs into via it's USB cable - schematic is here: USB Remote | CHDK Wiki | Fandom
I'm wondering whether a transistor would be suitable to fire the shutter? The camera only needs around 4.5v (a feed from the Arduino with a resistor to lower it slightly from 5v?) and 0.4ma to fire the shutter.
I've seen a couple of things on the net roughly talking about this but wanted to check before I damaged something!
Any advice would be great, cheers,
James
The circuit does use powerlines of the USB port which normally can take 5 volts, the article also says the voltage to fire the shutter should not be higher as 5 volts.
When High the voltage on an arduino-uno-pin is 5 volt.
So, you probably can connect the camera directly to ground and an outputpin of the arduino without other components.
The 5 volt limit is probably just a guideline preventing people to connect it to much higher voltages.
Although USB works with 5 volts, I can't imagine Canon not building in some... margin for errors. A USB card from factory A may deliver a little less while one from factory B may deliver a little more as 5 volts. Should... one ruin the camera using the last one, people would stop buying Canon rapidly.
To be sure the amount of mA doesn't get too high you could add a resistor in the range of 2-5 kilo-ohm. That way maximum current will be 1 - 2.5 mA, which is more then enough to trigger the shutter and way under the maximum amount an arduino-pin can handle.
Place it between arduinos output pin of choice and pin 1 (+5v) of the cameras USBport.
Thanks Simpson!
That sounds good. I'll give that a try.
I think I confused myself with the milliamps. I had 40mA's in my head for some reason not .4mA's which it only needs for the shutter.
Thanks again,
James