/*

Voltaat learn (http://learn.voltaat.com)

Link for full tutorial:

Tutorial: Building a device to read and visualize muscle activity using an Arduino board and an EMG (electromyography) sensor,

the EMG sensor will capture electrical signals generated by muscle contractions. We will use a screen to display the results

visually and also display the results through a graph on the computer, and we will controll servo motor with the muscle movement.

Connections from the Arduino to the breadboard:

• Arduino GND pin → Breadboard ground line

• Arduino 5V pin → Breadboard 5V line

Connection from the LCD:

• VCC pin → breadboard 5v line

• GND pin→ breadboard GND line

• SDA pin→ Arduino analog pin A4

• SCL pin → Arduino analog pin A5

Connections from the EMG sensor:

• SIG pin → Arduino analog pin A0

• GND pin→ breadboard GND line

Connections from the Batteries:

• The positive terminal of the first battery → +Vs port on the EMG sensor

• The negative terminal of the first battery → Middle GND port between +Vs and -Vs on the EMG sensor

• The positive terminal of the second battery → Middle GND port between +Vs and -Vs on the EMG sensor

• The negative terminal of the second battery → -Vs port on the EMG sensor

*/

#include "Servo.h"

#include "LiquidCrystal_I2C.h"

#define THRESHOLD 100 // Threshold to determine hand state

int EMGPIN = A0; // Analog pin connected to Muscle Sensor V3 Board

#define SERVOPIN 3 // Digital pin for the single servo

#define UPDATE_INTERVAL 500 // Update interval in milliseconds

// Initialize the I2C LCD (Address 0x27, 16 columns, 2 rows)

LiquidCrystal_I2C lcd(0x27, 16, 2);

Servo servo; // Define a single servo

unsigned long previousMillis = 0;

void openServo() {

   servo.write(0); // Open position

   lcd.clear();

   lcd.setCursor(0, 0);

   lcd.print("Muscle: Relaxed"); // Display relaxed status

   pinMode(EMGPIN,INPUT);

}

void closeServo() {

   servo.write(170); // Close position

   lcd.clear();

   lcd.setCursor(0, 0);

   lcd.print("Muscle: Contracted"); // Display contracted status

}

void setup() {

   Serial.begin(9600); // Set baud rate to 9600

   servo.attach(SERVOPIN); // Attach servo to the specified pin

   lcd.begin(16,2); // Initialize I2C LCD

   lcd.backlight(); // Turn on backlight

   lcd.setCursor(0, 0);

   lcd.print("Muscle Sensor"); // Display initial message

   pinMode(EMGPIN,INPUT);

}

void loop() {

   unsigned long currentMillis = millis();

   int value = analogRead(EMGPIN); // Read EMG sensor value

   if (currentMillis - previousMillis >= UPDATE_INTERVAL) {

       previousMillis = currentMillis;

       if (value > THRESHOLD) {

           closeServo(); // Close the servo if signal exceeds threshold

       } else {

           openServo(); // Otherwise, open the servo

       }

       lcd.setCursor(0, 1);

       lcd.print("output:"); // Display contracted status

       lcd.print(value); // Display contracted status

   }

   Serial.println(value); // Print sensor value to Serial Monitor

}

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