problem with matrix 8x8 max7219

i been trayin diferent codes and libraries and always get the same outcome, like this

if anyone can help me, i guess it could be any begginers mistake but i can figure it out

There have been several posts on this forum about the wrong type of matrices being supplied in kits purchased on eBay. The symptoms are that the LEDs stay on all the time or show nonsense as the matrix and the board are wired in an incompatible manner.


so, what its the problem, the matrix only or i should discard all the module?

For the problem described, both the matrix and the module are completely functional, it is merely that the matrix supplied is the version which has the LEDs connected in reverse to the version that works with the circuit board.

It is possible to utilise it by making connections between the circuit board and the matrix which exchange all row connections with the corresponding columns, but whether it is worth your while to do this is your decision.

You should raise a complaint with the vendor that you have been provided a non-functional unit. There is however, certainly no reason to dispose of either part as both are perfectly functional. The conundrum is that the sale price of the complete kit (notably on eBay) is generally the same or less than the price of the correct matrix itself, so either the seller provides you with a working replacement (which is not always practical as most such sellers do not have the expertise to comprehend the nature of the problem and are just as likely to provide another unit from their stock with exactly the same problem :astonished: ) or you try another dealer with the right stock (as in general, most do).

An interesting suggestion is that the "orphan" PCB with the MAX7219 is now an excellent base on which to assemble your own matrix from individual LEDs, such as to construct a 4 b 4 by 4 LED cube. :grinning: