Hello!
I wanted to have the cheapest possible foot switch I can get. And I dodn't want to settle with just one. The easiest way was to hook tje switches to the parallel port.
It only works with parallel ports that can make use od bidirectional data read/write (EPP mode). And you need ppdev kernel module.
The hardware is very simple. The data pins (2 through 9) on parport are pulled high and the reading on the pin is 1. By connecting a pin to the GND (pins 18 through 25 are all 0V) the reading of the pin is 0.
+---+---+---+---+---+---+---+------ pin 18..25 (GND) | | | | | | | | sw1 sw2 sw3 sw4 sw5 sw6 sw7 sw8 | | | | | | | | | | | | | | | +------ pin 9 (D7) | | | | | | +---------- pin 8 (D6) | | | | | +-------------- pin 7 (D5) | | | | +------------------ pin 6 (D4) | | | +---------------------- pin 5 (D3) | | +-------------------------- pin 4 (D2) | +------------------------------ pin 3 (D1) +---------------------------------- pin 2 (D0)
Included is parport.c and parport.pd if anybody wants to try them out. Sending 1 or 0 to the parport starts / stops periodic reading of the /dev/parport0.
It's only my first pd external and would be happy to get any suggestions.
Take care,
Miha...