BookScanner part3 - remote Controll cable
In part2 I installed the alternative chdk-firmware on my Canon A-490 cameras, because they allow to trigger the autofocus and the shutter function by using a USB cable. To Trigger these functions you need a cable that connects and disconnects the +5V line of a USB cable. The Data lines of the cable aren't used.
For my bookscanner I need to take a picture of the right and the left page of the book at the same time so I hooked up two usb-micro connectors to an USB-A connector and added a switch on the +5V cable. I connect the USB-A connector to a wall-plug and every time I press the switch the autofocus starts and a picture is taken when I release it again.
Works like charm. Now I need to create a mount for my cameras so they can be positioned correctly below the pages.