I am using a 16F690 PIC to control a latching solenoid on a valve. The latching solenoid requires a pulse with positive polarity to open and another pulse of negative polarity to close. Generating the postive polarity pulse at the output pin of the 16F690 is no problem, but I am not grasping how to generate a negative polarity pulse at a pin output. Can anyone advise me or refer me to an explanation? Thanks!