I have an external switch, momentary closure on an external event, that could be a right click USB mouse button, or it could be a single keyboard keypress of a key I’d never use. Any existing switch on USB line that could be shunted by my external switch.
The results of this switch closure would be as follows:
Switch closure. Place current time into cell 1. Move right to next cell, 2.
Next switch closure to place current time in cell 2. Move right to next cell. Now calculate elapsed time between cell 1 &2, record in the current cell. Move to cell below cell 1. Wait for next switch closure. Repeat above until manually stopped by operator.
Hope you can offer a direction for me to follow. Thanks. Tom