I'm making a digital clock (HH MM SS). Each digit will have 7 LEDs, rather than an actual 7-segment display. I have a few novice questions. First of all, take a look at my circuit diagram and see if everything looks okay.
Questions: - What size should the decoupling capacitors be? - From the MAX7219 datasheet, Rset should be between 22-24 kohms. (The LED's are 3.2V, 20mA) Can I alter Rset to affect the LED brightness? - Since Rset controls the current to the LEDs, do I even need a resistor on each LED? - I'm using the Arduino Uno. Which output pins should I use for CLK, Din, and LOAD(CS)? - If I wanted to put 2 LEDs on each segment (instead of 1), how would that affect Rset? And would the Arduino and the 7219 be able to handle it?
Thanks for your help!