Problems with 8x8 RGB LED Matrix

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tranha

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Hi All,

I don't know where to post this question because it's not really relevant to Teensy at all but I desperately need some help.

Currently, I'm working on a school project that needs to work with a 8x8 RGB LED Matrix as shown in the schematic below
Capture.JPG

Now, if I want to light up these 2 circled LEDs as shown below. How can I do this?
Capture2.JPG

By commonsense, you will say assert a 1 on pin 17 and 18, assert a 0 on pin 9 and 10. But with that settings, 4 LEDs will be lit up not just 2 as shown in the following picture...
Capture3.JPG

I don't really know how to resolve this issue in theory..

Please help me.
 
If you look at your last drawing and draw the voltages seen by each LED it will be pretty clear what is going on.

What you need to do is time share the LEDs. So if you set the column pins for one row, enable that row, wait 50ms and then turn that row off, change the column values to the next row and activate that row pin.
You are not doing true charlieplexing
https://en.wikipedia.org/wiki/Charlieplexing
But code solutions that time share the pixels are doing the same thing.
 
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