Well, Since this is kind of what Im working with figure I will ask here. Im using the same MAX7219. I have a micro simply counting from 0 to 9999. So far no problems with the code or the MAX7219 IC. My problem is this: Im using displays LSD8151. Its spec sheet says I should be driving the segments at around 21mA, so looking at the handy dandy table in the 7219 spec sheet I chose a 28K resistor for Rset @ 20mA. Display works fine. Im using the internal osc on the pic, and just a small 10uf cap at the LM7805 5V reg IC. That is where my problem is: the LM7805 is getting quite toasty running this thing. I did put a heat sink on it and its down to the point where I can touch it now with out burning myself, but my question is this: Is there a more efficient way to supply the 7219 with its power needs? I just cant help thinking alot of power is being wasted being disipated by so much heat.. or is it just normal for this to run so hot in this configuration?