Hi!
I'm working on a LED display and I want to see how much LEDs I can ultimately drive using a 5v, pic16f628. Now, I'm using 2 shift registers and multiplexing to drive 64 LEDs. Now I want to extend the amount of LEDs I'm using.
I'm "scanning" through the columns and only one column is on at a certain moment. Per column I put on the rows for which I want the LED to be on.
I heard that when I want to use more than 10 columns, I must push more current through the LEDs. I can imagine that this must be done because the time when the LED is on decreases when the number of columns increases. And pushing more current trhough them will let the shine brighter, so our eyes won't see a difference.... Is this why they need more current? And how many columns or rows can I use?
Greetings