Hi Brian,
It took a while for me to understand how this chip works and how the MAX7219 interfaces to this matrix. What I did found out is that the MAX is in fact a 7 segments driver intended for 8 digit displays. The MAX connections are grouped in segment control and Digit control. Instead of driving the 7 segments+dot it drives the 8 led's on a column basis. The LED per column are controlled by the segment drivers. The column it self is driven/selected by the Digit control of the MAX. Since the MAX is made only for Common cathode segments of a normal 7 Segment Display this must also be the case for the LED matrix. That's why the LED matrix on a per column basis must be of Common cathode type.
The Columns and rows are not nicely distributed over the 2x8 pinning, they are not mirrored and there for rotating them will not solve the problem. Hope this clears things up.
Thanks for responding
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Hi Klaus,
Thanks for your response, i think you can talk about a common cathode although its a little odd. Also see my response to Brian. The MAX is made for 7 segment type displays these exits in two flavors common cathode and anode. They abuse this MAX to control the individual columns of the led Matrix. The MAX doesn't know if its controlling a 7 segm display or Columns of LEDS from a led matrix. The direction of the leds stays the same if you compare it with a 7 segm display. On a matrix column basis the leds must have a common cathode and are driven on the anode side by the Segment control of the MAX. The meaning of common anode or cathode on the matrix it self is meaningless i agree.