how do I connect limit switches to a sliding door system controlled by Visual Basic software?

The limit switch system must detect if the door is open and if it is, the whole system must be disabled.

Use a USB to parallel port adapter, but OPTO-ISOLATE the inputs.

Personally, I wouldn't use a PC to drive a door.

frollard7 years ago
If you have a parallel port there are ways to literally read the pins *you can have several io pins directly on your motherboard*, but beware, this can fry your computer.  It's better to use something simple like an arduino or other microcontroller to translate the switch signals into a serial (via usb in the case of arduino) that the computer can read via a com port.

almost 'all' programming languages have access to the com ports - and serial data is easy to work with.