Objective: To get my USB keyboard to interface with an Arduino Uno board.
Constraints: I can't afford a USB host shield for now for Arduino. Currently available is a keyboard with PS/2 connector. That example is available here. However, it is silly going for such a keyboard, or, buy a USB to PS/2 converter at the moment.
Challenge: USB has VCC, GND, RX/TX. (Rx/Tx also labelled D+/D- respectively). The parallel port connector has the following:
Where will the D- pin go?