05: microcontroller programming

Tinkering with Arduino

This week we were tasked with building something with an Arduino. I used a few different inputs and outputs but the premise was simple:

I'd wave infront of a gesture sensor and the LCD would display "motion detected" and the servo motor would rotate.

If I continued waving, the LCD would display "Motion continued"

If I stopped waving, the LCD would display "Motion ended" and the servo motor would cease rotating.

Equipment

1x Adafruit Metro 328

1x PIR motion sensor HC-SR501

1x LCD 16x2

1x Breadboard trim potentiometer - 10K

1x Micro servo

Arduino code

#include "LiquidCrystal.h"
#include "Servo.h"

Servo myservo; 

LiquidCrystal lcd(7,8,9,10,11,12); // Creates an LC object. Parameters: (rs, enable, d4, d5, d6, d7) 
int inputPin = 3;               // choose the input pin (for PIR sensor)
int pirState = LOW;             // we start, assuming no motion detected
int val = 0;                    // variable for reading the pin status
int pos = 0;                    // start position for servo motor

void setup() {
  pinMode(inputPin, INPUT);     // declare sensor as input
  lcd.begin(16,2); // Initializes the interface to the LCD screen, and specifies the dimensions (width and height) of the display
  myservo.attach(5);  // attaches the servo on pin 5 to the servo object
  Serial.begin(9600);
}
 
void loop(){
  val = digitalRead(inputPin);  // read input value
  if (val == HIGH) {            // check if the input is HIGH
    if (pirState == LOW) {
      Serial.println("Motion detected!");      
      lcd.clear(); // Clears the display 
      lcd.setCursor(0,1); 
      lcd.print("Motion detected!");  // print on LCD display
      for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees in steps of 1 degree
        myservo.write(pos);  
        delay(15);  
        }
      for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
        myservo.write(pos);              // tell servo to go to position in variable 'pos'
        delay(15);                       // waits 15ms for the servo to reach the position
        }
      pirState = HIGH;
    }

    else {
      Serial.println("Motion continued"); 
      lcd.clear(); // Clears the display 
      lcd.setCursor(0,1); 
      lcd.print("Motion continued!"); // prnit on LCD display
      for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees in steps of 1 degree
        myservo.write(pos);  
        delay(15);  
        }
      for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
        myservo.write(pos);              // tell servo to go to position in variable 'pos'
        delay(15);                       // waits 15ms for the servo to reach the position
        }
      }
      pirState = HIGH;
    }
  
  else {
    if (pirState == HIGH){
      Serial.println("Motion ended!");
      lcd.clear(); // Clears the display 
      lcd.setCursor(0,1); 
      delay(150);// Sets the location at which subsequent text written to the LCD will be displayed 
      lcd.print("Motion ended!");// print on LCD display
      pirState = LOW;
    }
  }
}