A. press a key "U" every .5-1 second switchable by press of button "on/off" or switch
B. Press left mouse button every .5-1 second switchable by different press of another button "on/off" or switch
C. Potentiometer incorporated to adjust the delay of each of the above on the fly
D. If able to use poteniometer display on led display the active value either by scale 1-9 or use multiple to display percent "3 next to each other"
Led - https://www.amazon.com/gp/product/B00EZBGUMC/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1