Final Project Journal

The idea of my project is to design a smart robot-shaped vending machine Instead of the traditional way of pressing buttons, this machine is interactive – when children or guests point at the robot, it responds by dropping sweets

• connect H-bridge with DC motor in out 1 and out 2

• connect the +ve of adaptor 9 v  to the vcc of H-bridge 

• connect the -ve of the adaptor to the GND of arduino and the GND H-bridge 

• connect  ena with pin 3

• connect in1 with pin 5

• connect in2 with pin 6 

• connect   vcc of ultrasonic sensor with +ve of 5v 

• connect trig of ultrasonic sensor with pin 9 

• connect echo of ultrasonic sensor with pin 8 

• connect all the GNDs together 

• connect the Arduino with 9V  in Vin  pin 

• . Connect the on/ off switch with pin 2

#include <MD_MAX72xx.h>   

#include <SPI.h>          

#include "MD_EyePair.h"  

// ---------------- LED MATRIX ----------------

#define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW   

#define MAX_DEVICES 10                      

#define CLK_PIN 13   

#define DATA_PIN 11  

#define CS_PIN 10    

MD_MAX72XX M = MD_MAX72XX(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);

#define MAX_EYE_PAIR (MAX_DEVICES / 2)

MD_EyePair E[MAX_EYE_PAIR];

#define DELAYTIME 500 

// ---------------- ULTRASONIC SENSOR ----------------

#define trig 9  

#define echo 8 

float time = 0;    

float distance = 0; 

// ---------------- SWITCH ----------------

#define switchPin 2  

// ---------------- MOTOR (H-BRIDGE) ----------------

int ena = 3;  

int in1 = 5; 

int in2 = 6;

// ---------------- DECORATIVE LEDS ----------------

#define led1 A1  

#define led2 A2  

#define led3 A3  

#define led4 A4 

#define led5 A5  

// ---------------- SETUP FUNCTION ----------------

void setup() {

  M.begin();

  for (uint8_t i = 0; i < MAX_EYE_PAIR; i++)

    E[i].begin(i * 2, &M, DELAYTIME); 

    pinMode(switchPin, INPUT_PULLUP);

  // Setup ultrasonic sensor

  pinMode(trig, OUTPUT);

  pinMode(echo, INPUT);

  digitalWrite(trig, LOW); 

  // Start serial monitor for debugging distance values

  Serial.begin(9600);

  // Setup decorative LEDs as outputs

  pinMode(led1, OUTPUT);

  pinMode(led2, OUTPUT);

  pinMode(led3, OUTPUT);

  pinMode(led4, OUTPUT);

  pinMode(led5, OUTPUT);

  // Setup motor pins as outputs

  pinMode(ena, OUTPUT);

  pinMode(in1, OUTPUT);

  pinMode(in2, OUTPUT);

}

// ---------------- MAIN LOOP ----------------

void loop() {

  // Check if the switch is ON (HIGH because of INPUT_PULLUP)

  if (digitalRead(switchPin) == HIGH) {

    // Animate the eyes on LED matrix

    for (uint8_t i = 0; i < MAX_EYE_PAIR; i++)

      E[i].animate();

    // Turn on all 5 decorative LEDs

    digitalWrite(led1, HIGH);

    digitalWrite(led2, HIGH);

    digitalWrite(led3, HIGH);

    digitalWrite(led4, HIGH);

    digitalWrite(led5, HIGH);

    delay(1000);

    // Trigger ultrasonic sensor

    digitalWrite(trig, LOW);

    delay(2);

    digitalWrite(trig, HIGH);  

    delay(10);

    digitalWrite(trig, LOW);

    time = pulseIn(echo, HIGH);

    distance = time * 0.034 / 2;

    Serial.print("Distance: ");

    Serial.print(distance);

    Serial.println(" cm ");

     if (distance <= 50) {

     digitalWrite(in1, HIGH);  

     analogWrite(ena, 95);      

     delay(1090);              

     // Stop motor

     digitalWrite(in1, LOW);

     digitalWrite(in2, LOW);

     delay(1090);

    }

  }

  else {

      for (uint8_t i = 0; i < MAX_EYE_PAIR; i++)

      M.clear();

    digitalWrite(led1, LOW);

    digitalWrite(led2, LOW);

    digitalWrite(led3, LOW);

    digitalWrite(led4, LOW);

    digitalWrite(led5, LOW);

    digitalWrite(in1, LOW);

    digitalWrite(in2, LOW);

    analogWrite(ena, 0); 

  }