HC-SR04 Distance Sensor with ESP32 — ESP32 simulation

HC-SR04 ultrasonic distance sensor connected to an ESP32 DevKit, printing distance readings to serial.

An interactive ESP32 circuit simulation you can run free in your browser on Velxio, by thisisuseless888.

Components

• Junction x2
• Pro Dc Motor x2
• Battery 9V
• Breadboard Mini
• Hc Sr04
• Motor Driver L293D
• Resistor 330
• Ssd1306 I2C 4Pin

Sketch code

#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "ConfusedFra.h"
#include "AngryFra.h"
#include "HappyFra.h"
#include "motion.h"
#include "states.h"

enum moods {confused, angry, happy}; //only for simulation I will be adding 3 emotion states. The actual version will have more than this


float getDistance();
void emotions(moods mood);

//OLED
#define SCREEN_I2C_ADDR 0x3C // or 0x3C
#define SCREEN_WIDTH 128     // OLED display width, in pixels
#define SCREEN_HEIGHT 64     // OLED display height, in pixels
#define OLED_RST_PIN -1      // Reset pin (-1 if not available)

Adafruit_SSD1306 display(128, 64, &Wire, OLED_RST_PIN);

//sensor pinout
int ECHO = 18; 
int TRIG = 5;

//Motor pinout
/*int leftMortPos = 14; //in2
int leftMortNeg = 4; //in1
int rihgtMorPos = 27; //in3
int rihgtMorNeg =23; //in4
int ENA2= 12;
int ENA1 = 26;
*/

int frame =0;

void setup() {
  pinMode(ECHO, INPUT);
  pinMode(TRIG, OUTPUT);
  pinMode(leftMortNeg, OUTPUT);
  pinMode(leftMortPos, OUTPUT);
  pinMode(rihgtMorNeg, OUTPUT);
  pinMode(rihgtMorPos, OUTPUT);
  pinMode(ENA1, OUTPUT);
  pinMode(ENA2, OUTPUT);

  Serial.begin(115200);

  //when turned on, I want him to seem as if he was sleepign adn was woken up.

  display.begin(SSD1306_SWITCHCAPVCC, SCREEN_I2C_ADDR);
   
}

void loop() {
  
  float distance = getDistance();
  updateState(distance);

  if(distance < 5)
  {
    Serial.println("Stopped");
    emotions(angry);
    STop();
  }

  else if (distance < 20.0)
  {
    Serial.println("Object in front");
    emotions(confused);

    int turn = random(0, 2);
    if( turn == 0) {
      Serial.println("Turn right");
      rightTurn();
      delay(3000);
      STop();
   
    }

    else{
      Serial.println("Turn left");
      //turn right = false;
      leftTurn();
      delay(3000);
      STop();
    }
  }

   else
   {
    emotions(happy);
    moveForward();
   }
}

//function to get the distance
float getDistance() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);

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

  digitalWrite(TRIG, LOW);

  int duration = pulseIn(ECHO, HIGH, 30000);
  float distance = duration * 0.034 / 2;

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

  return distance;
}

void emotions(moods mood)
{
  display.clearDisplay();


  switch (mood) {
    case confused:
      display.drawBitmap(32, 0, Confusedframes[frame], ConfuFRAME_WIDTH, ConfuFRAME_HEIGHT, 1);
      frame = (frame + 1) % ConfuFRAME_COUNT;
      
      break;
      case angry:
      display.drawBitmap(40, 8, Angryframes[frame], AngFRAME_WIDTH, AngFRAME_HEIGHT, 
      1);
      frame = (frame + 1) % AngFRAME_COUNT;

      break; 
      case happy:
        display.drawBitmap(40, 8, Happyframes[frame], HapFRAME_WIDTH, HapFRAME_HEIGHT, 1);
        frame = (frame + 1) % HapFRAME_COUNT;

      break;

      default:
      Serial.println("HOW DID YOU GET HERE?");
      break;      
  
  }
   display.display();
   delay(FRAME_DELAY);
    
  }