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--- en:iot-open:practical:hardware:taltech:arduino:scenarios:lcd [2025/09/02 14:34] – [Suggested Knowledge Resources] raivo.sell
+++ en:iot-open:practical:hardware:taltech:arduino:scenarios:lcd [2025/09/02 14:42] (current) – raivo.sell
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+<pagebreak>
+====== Using LCD Display ======
+{{:en:iot-open:practical:hardware:taltech:arduino:scenarios:lcd.jpg?300|}}
+An alphanumeric LCD is a straightforward and widely used output device in embedded systems and IoT applications. The LCD used here has a fixed organization of 2 lines and 16 characters per line (2x16).
+This scenario guides you through displaying text on the LCD using Arduino.
+===== Prerequisites =====
+  * Familiarize yourself with the Arduino hardware reference.
+  * Install the LiquidCrystal library (built-in Arduino library).
+===== Hardware Connections =====
+^ LCD Pin        ^ Arduino Pin  ^
+| RS             | 8            |
+| EN             | 9            |
+| D4             | 4            |
+| D5             | 5            |
+| D6             | 6            |
+| D7             | 7            |
+| Buttons Input  | A0           |
+===== Task =====
+Display the text "Hello World" on the first line and "Hello IoT" on the second line of the LCD.
+===== Steps =====
+=== Step 1: Include Library ===
+Add the LCD library to your Arduino sketch:
+<code c>
+#include <LiquidCrystal.h>
+</code>
+=== Step 2: Declare GPIO Pins ===
+Define GPIO pins connected to LCD control lines:
+<code c>
+const int rs = 8, en = 9, d4 = 4, d5 = 5, d6 = 6, d7 = 7;
+</code>
+=== Step 3: Initialize LCD ===
+Create an instance of the LCD:
+<code c>
+LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
+</code>
+Set up the display dimensions (2 rows, 16 columns):
+<code c>
+lcd.begin(16, 2);
+</code>
+=== Step 4: Display Text ===
+Write text to the LCD screen:
+<code c>
+lcd.setCursor(0, 0); // top left corner
+lcd.print("Hello World");
+lcd.setCursor(0, 1); // second line
+lcd.print("Hello IoT");
+</code>
+===== Validation =====
+The LCD should clearly display "Hello World" on line 1 and "Hello IoT" on line 2.
+===== Useful Methods =====
+  * ''lcd.clear()'' – clears all text from the LCD.
+  * ''lcd.setCursor(col, row)'' – positions the cursor.
+  * ''lcd.print(data)'' – prints data to the display.
+===== Troubleshooting =====
+If the LCD shows incorrect characters or nothing:
+  - Double-check wiring and pin assignments.
+  - Verify correct initialization (`lcd.begin(16,2)`).
+  - Adjust the contrast potentiometer on the LCD, if available.