LEDTriks: Matrix Selection basics?

[VIDGuide]

Ok, this is probably the stupidest question ever asked here, but i'll ask it anyway coz i'm curious :)

in say 8x8 grid matrix, you have
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX

To turn on Led 2 in, 2 down, you'd turn on power to column 2, row 2, correct?

to also turn on Led 2 in, 4 down, you'd also turn on power to row 4 as well..

WHat then happens if you turn on power at column 4 in row 3, why does column 2 not also light?


+ +
XXXXXXXX
+ X+XXXXXX
+ X?XXX+XX
+ X+XXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX
XXXXXXXX

Ok, thats a really bad ascii :) I hope this question makes sense :)

[daviddth]

The LED's are turned on 1 at a time for a very short time in each section. Your eyes see the flicker as a continuous image, thus no extra lights are turned on by accident

[alwysrit2]

I believe you mean it is turnes on one row at a time. Somewhere I read that it needs to be ran at 60 hz or faster, not sure how often Vixen actually does the update.
-Don

[Ronp]

Read this on computerchristmas is RJs basic description of how it works
http://computerchristmas.com/christmas/link-how_to/HowToId-112/LowLimit-5

[omzig]

I believe the process is called multiplexing. Here is a pretty good article on it: http://ezinearticles.com/?How-To-Drive-A-64-Led-Matrix-Display-Using-16-Control-Lines&id=637573

Also interesting: (more technical): http://www.winpicprog.co.uk/pic_tutorial13.htm