Hat CBack Driver Arduino Tutorial

#include <M5Unified.h>
#include "M5HatCBackDriver.h"

M5HatCBackDriver driver;

void setup()
{
   M5.begin();
   Serial.begin(115200);
   Wire.begin(0, 26);
   M5.Display.setFont(&fonts::FreeMonoBold9pt7b);
   M5.Display.setRotation(1);
   while (!driver.begin(&Wire, M5_HAT_CBACK_DRIVER_I2C_ADDR)) {
       M5.Display.fillScreen(YELLOW);
       Serial.println("Hat CBack Driver Init Fail");
       M5.Display.setCursor(0, 0);
       M5.Display.println("Hat CBack Driver Init Fail");
       delay(1000);
   };
   M5.Display.setCursor(0, 0);
   M5.Display.fillScreen(GREEN);
   Serial.println("Hat CBack Driver Init OK");
   M5.Display.println("Hat CBack Driver Init OK");
   M5.Display.println("Start Control Servo");
}

void loop()
{
   for (int i = 0; i <= 3; i++) {   // channel 0-3
       driver.setServoAngle(i, 0);  // 0-180 degree
       // driver.setServoPulse(i,500); // 500-2500us
       delay(200);
   }
   for (int i = 0; i <= 3; i++) {     // channel 0-3
       driver.setServoAngle(i, 180);  // 0-180 degree
       // driver.setServoPulse(i,2500);  // 500-2500us
       delay(200);
   }
   driver.digitalWritePortB(1);
   delay(1000);
   driver.digitalWritePortB(0);
   Serial.print("PortB Analog Read: ");
   Serial.println(driver.analogReadPortB());
}