Hello all, This question is only marginally related to pic's since I am going to use a 16C84 to control the chopper, but there seem to be quite a few bright people out there who may be able to help... I am trying to make an incandescent lamp dimmer from a 16C84 and planned on doing a simple waveform chop using a triac. I realized, however, that since the pic is going to be doing a bunch of other time sensitive stuff that I don't have the processor time to manually sense the zero and chop the wave using the pic. So, is there any easy method to passively (from the pic's point of view) chop the AC wave? i.e. use 8 I/O pins to a D-A to give a reference to the chopper circuit and have it do the rest? That way I can just output the light level to the pins and it would stay put leaving the rest of the processor available? Thanks for any help, aaron ------------------------------------------------------------------------------- - Aaron J. Miller Email: millera@stanford.edu - Physics Graduate Student Web : http://www.stanford.edu/~millera - Stanford University Phone: (415) 372-5575 (until 4/12/97) -------------------------------------------------------------------------------