// Program to demonstrate the MD_Parola library
//
// Uses the Arduino Print Class extension with various output types
//
// MD_MAX72XX library can be found at GitHub - MajicDesigns/MD_MAX72XX: LED Matrix Library
//
// Define the number of devices we have in the chain and the hardware interface
// NOTE: These pin numbers will probably not work with your hardware and may
// need to be adapted #define HARDWARE_TYPE MD_MAX72XX::FC16_HW #define MAX_DEVICES 11
char myString[] = " class "
" subject "
" time "
" prof ";
defines one long string. Is that your intention? Or are you trying to define 4 different messages?
It is hard to read your mind, so you really need to explain what you are trying to do with this code.
If you use print you don't have any options for formatting. Read some of the other examples and the extensive documentation for the library to see if that gives you any ideas.
Those modules with the right angle pin headers are a real pain. Almost impossible to work with if the displays are not socketed as you cannot un-solder the headers. Probably cut the header pins off at the right angle and solder them together, one to the next with little pieces of wire.
Or better, twist the right angle part ever so slightly so that when you put the adjacent boards together, they just slip together, cur the pins short so that there is about 4 mm overlap and just solder the overlapped pins together.