I would like to power up my A2500 using CHDK PTP script without physical touch to the camera. Is that possible?
Or any other tricks to do that?
No. When the camera is off nothing is running*.
To power on by remote control, your options are:
1) Mechanical control of the power button with a servo or something like that.
2) Keep the power button held down, and control an external power supply.
3) Hack out the power button and replace it with your own electrical control.
* For completeness some very old had something that could detect if there was power applied to the USB port and power on in response.
