controlling a cheap digital camera

Development Boards MicroMod
1

I am controlling a small digital camera, using a lilypad. I soldered a wire to either side of the button that turns the camera on and measured the voltage between these two wires. The voltage is 320 when the camera is on. I ended up only connecting the positive wire to the microcontroller and setting the pin as input. To turn on the camera, I change the pin to output (low) momentarily and back to input. I am doing this because it’s the only thing that works.

I am wondering if setting the pin to input might drain the battery on the camera or cause other problems. Setting the pin to output (high) then momentarily low then high again does not work, nor does low, high, low…

2

It looks like a pulled-up input signal then (the high side).

AVRs have a very high input pin resistance. You’re likely not putting much of a drain on it. The only way to be sure is actually measuring the current consumed by the circuit. You can try making a battery “wedge” - two conductive strips with an insulator in between - and putting that over the camera’s battery terminal and outside of the battery compartment. Slide the battery in, and then probe the current.