Hi again,
I was hoping someone might help me out with an electronics thing. I've got a small camera with a button to turn it on etc. I've soldered 2 wires around the button, so when I touch them together it "presses" the button - this works as expected.
I want to power the camera from the arduino 5v (this is the correct voltage), and use output pins to "press" the button. How should I wire this up? Do I need a transistor to do this? I've measured the voltage across the "button" wire and there is 5v flowing through it, but when I ground the - then it doesn't work as expected. Should I ignore the + "button" wire, and feed 5v from the output pin to the - "button" wire? Or is it not that simple?
Cheers for the help
Insufficient juice
if the camera is usually powered by a usb port the 5v it might need 1 or 2 amps. Way more then the arduino 5v pin can provide. And the Vcc from the usb on the uno has a 500ma fuse before you can tap the power coming in. I have taped 5v from a usb cable directly or you can run a separate cable for the camera.
As for triggering the camera i would use a transistor or a relay.
What are you doing with the captures pictures. if you are processing them with the arduino you might want to look at the CMU cam5 (pixicam) its arduino based and has the processing built in.
Good luck.
Hey RGF,The camera is
Hey RGF,
The camera is usually powered by a small lithium battery. It’s a standalone video recorder that saves video onto an sd card - I plan on using it in front of the dog bowl so I can collect small video’s of my dog drinking 
I guess you’re right about the insufficient juice - i’ll power it directly from 4 AA batteries instead. I’ll use an opto coupler to “press” the button. I don’t need the arduino to get the video (yet) so that should work.
Thanks for pointing me in the right direction
Cheers
In that case
If you use 4 rechargeable cells (4.8v) you can replace your $25 Arduino with a $3 attiny45.
I think if you checked the wires from the button i bet one of them is hooked to ground. if that’s the case you can probably hook the other wire to the arduino or attiny directly.
Got to run to the robot party.
The easiest way is to
The easiest way is to control the camera switch is with a relay. The arduino ttl output can not handle the current for the relay. You will need to add a 2n2222 transistor in between the arduino ttl output and the relay. Hope this helps
