Hi! > You can use two pins to a 2 bit D/A made from resistors to get the four > voltage levels, then use these to drive a current source. You could also > use a single PIC output pin with PWM. Thanks!. Sure that PWM is a solution, as Wouter said, but I was looking for that D/A idea. Cheers, Diego. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.