Measure distance by Grove ultrasonic sensor using M5Stack.

ultrasonic_001.ino

#include <M5Stack.h>
#include <Ultrasonic.h>

const int USONIC_PIN = 2;
Ultrasonic ultrasonic(USONIC_PIN);

void setup() {
  M5.begin();
  M5.Lcd.setTextSize(2);
}

void loop() {
  long distance = ultrasonic.MeasureInCentimeters();
  M5.Lcd.printf("Distance %ld cm\n", distance);
  delay(5000);
}