SDM 1.60 and later detects an ordinary USB switch and the Ricoh CA1 switch.
The Ricoh switch applies pulses to the USB V+ and ground connections at about 5V peak so should work with all supported cameras.
The pulse-patterns change for half=press, full-press and Off.
For the CA-1, operation is like on normal camera, half-press to focus and full-press and release to take a photo.
The ordinary switch is clicked on/off to focus and on/off again to take the photo.
After loading SDM, you can immediately use either of the remote switches (Direct mode) without entering <ALT> menu-mode.
You can also use the remote switches in the existing script mode.