บทเรียนที่ 71: วัดระยะทางและแสดงผลบนหน้าจอ LCD | คอร์สเรียน Arduino ทีละขั้นตอน

 /*
  * S08-03
 * Using LCD1602-I2C and HC-SR04 Ultrasonic Sensor with Arduino
 * Written/updated by Ahmad Shamshiri for Robojax (Robojax.com)
 * on January 16, 2019 at 15:51 in Ajax, Ontario, Canada

   
 * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
 * This code has been download from Robojax.com
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <NewPing.h>

#define TRIGGER_PIN  12  // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN     11  // Arduino pin tied to echo pin on the ultrasonic sensor.
#define MAX_DISTANCE 200 // Maximum distance we want to ping for (in centimeters). Maximum sensor distance is rated at 400-500cm.

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.

// start of settings for LCD1602-I2C
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
// Set the LCD address to 0x3F for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x3F, 16, 2);
int VCC2 = 2;
// end of settings for LCD1602-I2C

void setup() {
  Serial.begin(9600); // Open serial monitor at 19600 baud to see ping results.

  pinMode(VCC2, OUTPUT);// extra VCC for LCD
  digitalWrite(VCC2, HIGH);//extra VCC is now HIGH (5V)
  // initialize the LCD, 
  lcd.begin();
  // Turn on the blacklight and print a message.
  lcd.backlight();
  lcd.clear();
  lcd.setCursor (0,0); //
  lcd.print("Robojax LCD1602"); 
   
}

void loop() {
  delay(50);                     // Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.
   lcd.clear();// clearn previous values from screen
  lcd.setCursor (0,0); //character zero, line 1
  lcd.print("LCD1602 HC-SR04"); // print text 

  // print distance in cm
  lcd.setCursor (0,1); //character 0, line 2
  lcd.print(sonar.ping_cm());// print distance in cm
  lcd.setCursor (3,1); //character 4, line 2 
  lcd.print("cm");// print "cm" on the display 

   // print distance in inch
  lcd.setCursor (7,1); //character 8, line 2
  lcd.print(sonar.ping_in());// print distance in cm
  lcd.setCursor (9,1); //character 4, line 2 
  lcd.print("inches");// print "cm" on the display  
  
  Serial.print("Ping: ");
  Serial.print(sonar.ping_cm()); // Send ping, get distance in cm and print result (0 = outside set distance range)
  Serial.print("cm");
  Serial.print(", ");
  Serial.print(sonar.ping_in());
  Serial.println("in");
  int distance = sonar.ping_cm();

}