I am trying to understand library capability for Max7219 8x8 matrix modules.
I want to make a dual timezone clock display.
I also want to do hours, minutes, seconds, and a label for UTC or local time.
So I am thinking about 2 or 3 of the "4-in-1" 8x8 matrix modules (8 to 12 positions?) for
each timezone line, so I can fit all the characters on the display. But when I tried the example
library test programs for a single long string of FC-16 "8x8" matrix modules, they start to
corrupt, probably due to noise and signal line loading, and may require a number of 74HC04
line buffer ICs added. (Or use shorter module strings.) It will also take a lot longer in milli-
seconds to update a very long display module string.
One thought; Does this library support using multiple CS select lines for making
two separate shorter strings of the 8x8 matrix modules? I was thinking something
#define MAX_DEVICES 12
#define CLK_PIN 13 // or SCK
#define DATA_PIN 11 // or MOSI
#define CS1_PIN 10 // SS for module string one.
#define CS2_PIN 9 // SS for module string two.
D_MAX72XX mx1 = MD_MAX72XX(CS_PIN, MAX_DEVICES); // Moudle string "mx1" UTC Time
D_MAX72XX mx2 = MD_MAX72XX(CS_PIN, MAX_DEVICES); // Moudle string "mx2" Local Time
That way, one of the above strings could be for each timezone and label.
Each would be shorter, hence take less time to update.
But if the library does support this, then how do I treat the MAX_DEVICES variable?
Is that the max number of devices in ONE string, like 12 or 16, or is it the sum total
of all modules used in both strings of devices?
[Disclaimer: I am very new at working with Arduino. I may simply be not using this
correctly, or have the wrong idea all together. Please feel free to laugh first, and then
point me in another direction for the project.]