/*
********************************************
  14CORE ULTRASONIC DISTANCE SENSOR CODE TEST
********************************************

  HC-SR04

  https://www.14core.com/wiring-esp8266-nodemcu-with-hcsr04-ultrasonic-sensor/

  TM1637

  https://github.com/avishorp/TM1637
  https://www.makerguides.com/tm1637-arduino-tutorial/

  LGT8F328P

  https://github.com/dbuezas/lgt8fx

      A
     ---
  F |   | B
     -G-
  E |   | C
     ---
      D     P

  PGFEDCBA

  P - decimal point
*/

#include "TM1637Display.h"

#define CLK                  2 //12
#define DIO                  3 //11
#define TRIGGER              4 //Tx //6
#define ECHO                 5 //Rx //9
#define BUILTIN_LED         13
#define SERIAL_BAUDRATE   9600
#define MAX_DISTANCE       800

TM1637Display display(CLK, DIO);

void setup() {

  Serial.begin (SERIAL_BAUDRATE);
  delay(10);

  Serial.println("HC-SR04 TM1637 Abstandsmessung");

  pinMode     (TRIGGER, OUTPUT);
  pinMode     (ECHO,    INPUT);

  pinMode     (BUILTIN_LED, OUTPUT);
  digitalWrite(BUILTIN_LED, HIGH);

  // check out TM1637 display
  // Print number in different locations
  /*
    for (byte i = 0; i < 4; i++) {

      display.showNumberDec(i, false, 1, i);
      delay(500);
      display.clear();
    }

    display.clear();
    delay(500);
  */

  display.setBrightness(0x0f);
  display.clear();
}

void loop() {

  long duration, distance;

  //digitalWrite(ledPin, HIGH);

  digitalWrite(TRIGGER, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIGGER, HIGH);
  delayMicroseconds(10);

  digitalWrite(TRIGGER, LOW);
  duration = pulseIn(ECHO, HIGH);
  distance = (duration / 2) / 29.1;

  Serial.print(distance);
  Serial.println(" cm");

  if (distance > MAX_DISTANCE)
    display.clear();
  else {

    display.showNumberDec (distance, false); //1 23

    delay(950);
    digitalWrite(BUILTIN_LED, HIGH);
    delay(50);
    digitalWrite(BUILTIN_LED, LOW);
  }
}