Pressure Sensor - MS5611 Barometer problem

#include <AP_Common.h>
#include <AP_Progmem.h>
#include <AP_Param.h>
#include <AP_Math.h>
#include <AP_HAL.h>
#include <AP_Buffer.h>
#include <Filter.h>
#include <AP_Baro.h>

#include <AP_HAL_AVR.h>
const AP_HAL::HAL& hal = AP_HAL_BOARD_DRIVER;

#if CONFIG_HAL_BOARD == HAL_BOARD_APM2

AP_Baro_MS5611 baro(&AP_Baro_MS5611::spi);
static uint32_t timer;

void setup()
{
    hal.console->println("APM2 MS5611 Barometer library test");

    hal.scheduler->delay(1000);

    /* What's this for? */
    hal.gpio->pinMode(63, HAL_GPIO_OUTPUT);
    hal.gpio->write(63, 1);
    
    baro.init();
    baro.calibrate();

    timer = hal.scheduler->micros();
}

void loop()
{
    if((hal.scheduler->micros() - timer) > 100000UL) {
        timer = hal.scheduler->micros();
        baro.read();
        uint32_t read_time = hal.scheduler->micros() - timer;
        if (!baro.healthy) {
            hal.console->println("not healthy");
            return;
        }
        hal.console->print("Pressure:");
        hal.console->print(baro.get_pressure());
        hal.console->print(" Temperature:");
        hal.console->print(baro.get_temperature());
        hal.console->print(" Altitude:");
        hal.console->print(baro.get_altitude());
        hal.console->printf(" climb=%.2f t=%u samples=%u",
                      baro.get_climb_rate(),
                      (unsigned)read_time,
                      (unsigned)baro.get_pressure_samples());
        hal.console->println();
    }
}

#else // Non-APM2
#warning AP_Baro_MS5611_test built as stub for APM1
void setup () {}
void loop () {}
#endif

AP_HAL_MAIN();

what is this function => hal.scheduler->delay(1000);?
why should need to use this ?

where can I find the reading data’s pattern ?
how long will it read the data?

libraries.rar (1.51 MB)

No link to the used libraries, no link to the used hardware. Did you read the sticky note at the top of the forum?