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Potentiometer scale value

This project is designed to read the value from a potentiometer and display the read value on an LCD 1620 with an I2C interface. The value is also sent to the serial monitor for real-time viewing. A unique feature of this project is the visual representation of the potentiometer’s value on the LCD, displaying a bar that varies in length corresponding to the value.

1. Build the Circuit

• Arduino UNO R4 Minima Board

• Potentiometer Module

• I2C LCD 1602

2. Code

1. Open the 10-Potentiometer_scale_value.ino file under the path of ultimate-sensor-kit\fun_project\10-Potentiometer_scale_value, or copy this code into Arduino IDE.

3. Code explanation

The project functions by continually reading the value from a connected potentiometer. This value is then mapped to a smaller scale (0-16) and represented both numerically and visually on the LCD. By checking the difference between consecutive readings, the code ensures that only significant changes are reflected on the display, thereby reducing jitter. Reducing jitter helps avoid undesirable visual effects resulting from frequent refreshing of the LCD screen.

1. Library Inclusion and Initialization:

   #include <Wire.h>
   #include <LiquidCrystal_I2C.h>
   LiquidCrystal_I2C lcd(0x27, 16, 2);
   

   Here, the required libraries (Wire for I2C communication and LiquidCrystal_I2C for the LCD) are included. An LCD object is created with the I2C address 0x27 and is defined to have 16 columns and 2 rows.

2. Variable Declaration:

   int lastRead = 0;     // Previous potentiometer value
   int currentRead = 0;  // Current potentiometer value
   

   lastRead stores the previously read potentiometer value. currentRead will store the current reading from the potentiometer.

3. setup() Function:

   void setup() {
     lcd.init();          // Initialize the LCD
     lcd.backlight();     // Turn on the LCD backlight
     Serial.begin(9600);  // Start serial communication at 9600 baud rate
   }
   

   The LCD is initialized, its backlight is turned on, and serial communication is started at a baud rate of 9600.

4. Main Loop:

   void loop() {
     int currentRead = analogRead(A0);
     int barLength = map(currentRead, 0, 1023, 0, 16);
     if (abs(lastRead - currentRead) > 2) {
       lcd.clear();
       lcd.setCursor(0, 0);
       lcd.print("Value:");
       lcd.setCursor(7, 0);
       lcd.print(currentRead);
       Serial.println(currentRead);
       for (int i = 0; i < barLength; i++) {
         lcd.setCursor(i, 1);
         lcd.print(char(255));
       }
     }
     lastRead = currentRead;
     delay(200);
   }
   

   • The potentiometer value is read and mapped to a bar length (0-16).

   • If the difference between the last and current reading is more than 2, the LCD is updated.

   • The value is printed on the first row and a bar (based on the mapped value) on the second row.

   • The value is also sent to the serial monitor.

   • Before the next iteration, lastRead is updated, and a delay of 200ms is introduced for stability.