Hi, I see many people getting an "error: 'prog_uchar' does not name a type"
message: You need to replace 'prog_uchar' with 'const unsigned char' in the
examples.
My problem is different: All characters appear rotated 90 degrees
counterclockwise, and shifting downwards instead of right to left. Once a char
disappears from the bottom of a LED matrix it reappears at the top of the next
matrix to the right, and so on..
The module I am using consists of a strip of four LED matrices each controlled
by a MAX7219 the next being cascaded to the previous (dout > din) and clk/cs
being tied together.
Not sure why this is happening, maybe the design has changed, my guess is this
needs to be fixed in the library functions themselves. I have been trying to
play a bit with the setDot function in order to find a way to compensate for
the tilting chars, what I found out is that the col and row appear to be
reversed in relation to the LED module (starting at the bottom, position 0,0
lights the bottom leftmost LED on the rightmost module, then as I increase the
column value, it lights up the LED a row above, up to 7,0 where the leftmost
LED at the top row is lit. Once I set column = 8 the next module to the left
gets the leftmost LED at the bottom row lit).
I figured that "n = col / 8" sorts out which module to address for a given col
value, but I couldn't for the life of me, figure out what the next line is
doing (it's a modulus operation performed on col and 8) and how to correctly
shift out the bits to get my modules working right.
Original issue reported on code.google.com by wmoecke on 9 Mar 2015 at 2:42
Original issue reported on code.google.com by
wmoeckeon 9 Mar 2015 at 2:42