MD_MAX72XX displaying multiple ints

[outdoorescapehoeven]

How can i display the hrs, mins and secs in one line on my 32x8 LEDmatrix? This is the code i have so far:

#include <MD_Parola.h>
#include <MD_MAX72XX.h>
#include <SPI.h>

#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define MAX_DEVICES 4

#define CLK_PIN   13
#define DATA_PIN  11
#define CS_PIN    10

// Hardware SPI connection
MD_Parola P = MD_Parola(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);

// DEFINES
// Macros to retrieve the fractional seconds and minute parts of a time supplied in ms
#define numberOfSeconds(_time_) ((_time_ / 1000) % 60)
#define numberOfMinutes(_time_) (((_time_ / 1000) / 60) % 60)

// INCLUDES

// CONSTANTS

// GLOBALS

// 1000 ms in 1 sec, 60 secs in 1 min. So 180 mins = 1000x60x180= 10800000
unsigned long timeLimit = 10800000;

void setup() {
Serial.begin(9600);
P.begin();
}

void countdown() {

  // Calculate the time remaining
  unsigned long timeRemaining = timeLimit - millis();

  while (timeRemaining > 0) {
    // To display the time in hrs:mins:secs we need to seperate those parts
    int seconds = numberOfSeconds (timeRemaining);
    int minutes = numberOfMinutes (timeRemaining);
    
    P.print(seconds);

    // Update the time remaining
    timeRemaining = timeLimit - millis();
  }
}

void loop() {

countdown();

}

The timer works ok, i tested it with the serial monitor.

Thanks in advance!

[J-M-L]

there are tons of examples here

MD_Parola/examples at main · MajicDesigns/MD_Parola

have you looked at those?

[outdoorescapehoeven]

Yes i did. But i can't seem to find out how i can display my ints in one line on the display.

[J-M-L]

the simple way : Build a cString (a null terminated char array) and call the displayText() method

sprintf() or better snprintf() can help

[outdoorescapehoeven]

Thank you for your help. Unfortunately i don't have the knowledge to understand that. Could you give me an example on how i can attach the mins and secs in this cString?

[J-M-L]

Something like this:

char message[10]; 
int seconds = 9;
int minutes = 20;
snprintf(message, sizeof message, "%2d:%02d", minutes, seconds);  // builds "20:09"

then message is your string you can print.

here is the doc on that function:

https://www.cplusplus.com/reference/cstdio/snprintf/

you'll find the specifiers (how you tell the format expected for the string) in the printf() documentation

https://www.cplusplus.com/reference/cstdio/printf/