Here’s a look inside. It’s pretty basic. When you press the power button the LED glows dimly then brightly, and then it stays on. If you press the shutter button at this point then the LED goes out briefly and you have taken a picture. If you hold the shutter button down then the LED shuts off and you are recording video. I think this is quite a clever way to use a single LED.
Anyway the plan is to run the Atmel directly from the battery and intercept the on/off button press to wake from sleep. Then wake the rest of the module, wait for the LED to turn fully on and take a picture. Then power off the module, sleep for 30 seconds and do it again.