How To Scroll Display LCD Left?

Content Menu

● Introduction

● Understanding LCDs and Scrolling

● Why Scroll Text Left?

● Hardware Requirements

● Wiring Diagrams and Circuit Schematics

>> Standard Parallel Connection

>> I2C Connection

● Scrolling Techniques

>> Using Built-in LCD Commands

>>> Example Flow

>> Manual Scrolling Logic

>> Scrolling with Buttons

>> I2C LCD Scrolling

● Practical Applications

● Tips for Smooth Scrolling

● Common Pitfalls and Solutions

● Conclusion

● Frequently Asked Questions

>> 1. How do I scroll text left on a 16x2 LCD using Arduino?

>> 2. Why does my message repeat before fully disappearing when scrolling?

>> 3. Can I scroll only one line of a multi-line LCD?

>> 4. How can I control the scrolling speed?

>> 5. What are the advantages of using an I2C LCD for scrolling?

>> 6. What should I do if my LCD shows nothing or garbled text?

● Citations:

Scrolling text on an LCD display is a fundamental technique for presenting information that exceeds the limited visible area of typical character LCDs, such as the popular 16x2 or 20x4 modules. Whether you're building an Arduino project, crafting a digital information board, or simply want to enhance your embedded systems skills, mastering the art of scrolling display LCD left is essential.

This article provides an in-depth exploration of LCD scrolling, focusing on the leftward movement of text. You'll find detailed explanations, practical applications, plenty of diagrams, and curated video tutorials to support your learning. At the end, you'll find a conclusion, a word count, and a set of frequently asked questions with answers.

Introduction

Character LCDs, especially those based on the Hitachi HD44780 controller, are ubiquitous in electronics projects. Their simplicity, affordability, and versatility make them ideal for displaying messages, sensor data, or user prompts. However, their limited character width (typically 16 or 20 characters per line) can be restrictive. Scrolling text left allows you to display longer messages in a visually appealing way, making your projects more interactive and informative[1][3][13].

Understanding LCDs and Scrolling

Character LCDs display text in a fixed grid, such as 16 columns by 2 rows. When your message exceeds the display width, you can scroll the text left to reveal hidden content. This is achieved by shifting the entire display memory, effectively moving the visible window over your message[1][3][13].

Why Scroll Text Left?

- Display Long Messages: Show information that exceeds the screen width.

- Create Dynamic Displays: Attract attention with moving text.

- Improve Readability: Prevent text truncation and allow users to read complete messages.

- User Interaction: Combine scrolling with buttons for manual navigation[4].

Hardware Requirements

To implement leftward scrolling on an LCD, you'll need:

- Arduino board (Uno, Nano, Mega, etc.)

- Character LCD (16x2, 20x4, etc., HD44780 compatible)

- Potentiometer (for contrast adjustment)

- Resistors (for backlight, typically 220Ω)

- Breadboard and jumper wires

- Optional: I2C LCD adapter for simplified wiring[1][3][10]

Wiring Diagrams and Circuit Schematics

Standard Parallel Connection

LCD Pin	Arduino Pin	Description
RS	Digital 12	Register Select
E	Digital 11	Enable
D4	Digital 5	Data 4
D5	Digital 4	Data 5
D6	Digital 3	Data 6
D7	Digital 2	Data 7
VSS	GND	Ground
VDD	5V	Power
VO	Potentiometer	Contrast Adjust
A/K	5V/GND + 220Ω	Backlight

I2C Connection

- SDA → Arduino A4

- SCL → Arduino A5

- VCC → 5V

- GND → GND

Scrolling Techniques

Using Built-in LCD Commands

The HD44780 controller and Arduino LiquidCrystal library provide functions for scrolling:

- scrollDisplayLeft(): Shifts the entire display one position to the left.

- scrollDisplayRight(): Shifts the display right.

These functions move all visible characters, including the cursor, left or right by one position[1][3][13].

Example Flow

1. Print a long message to the LCD.

2. Use a loop to call `scrollDisplayLeft()` repeatedly with a delay.

3. The message appears to move left, revealing hidden characters.

Manual Scrolling Logic

For more control, you can implement manual scrolling by updating the display with substrings of your message. This allows for scrolling a single line or custom effects[2][11][14].

Scrolling with Buttons

Add push buttons to allow users to scroll left or right manually. Each button press triggers a scroll in the desired direction[4].

I2C LCD Scrolling

I2C LCDs simplify wiring and support the same scrolling functions. The logic remains the same, but you use an I2C library for communication[10][12].

Practical Applications

- Menu Navigation: Scroll through menu items or long descriptions.

- Sensor Data: Display time-series data or logs.

- Status Messages: Alert users with dynamic notifications.

- Information Boards: Show news, weather, or advertisements[8].

Tips for Smooth Scrolling

- Adjust Delay: Use appropriate delay between scrolls for readability (e.g., 150–500 ms)[13].

- Clear Display Carefully: Avoid clearing the display too often to prevent flicker[7].

- Handle Message Length: Calculate the exact number of scrolls needed based on message and display length[7][13].

- Use Spaces: Pad your message with spaces if you want a pause before it repeats[7].

Common Pitfalls and Solutions

Conclusion

Scrolling text left on an LCD display is a powerful technique for presenting long messages within the constraints of limited display space. By leveraging built-in commands like `scrollDisplayLeft()`, manual substring logic, or user-controlled buttons, you can create dynamic and interactive interfaces for your electronics projects. Proper wiring, thoughtful delay management, and understanding the nuances of your display will ensure smooth, flicker-free scrolling.

Whether you're using a standard parallel LCD or an I2C module, the principles remain the same. Experiment with different scrolling speeds, message lengths, and user controls to find the best fit for your application. With these skills, you can enhance any project that relies on clear, engaging text output.

Frequently Asked Questions

1. How do I scroll text left on a 16x2 LCD using Arduino?

You can use the `scrollDisplayLeft()` function from the LiquidCrystal library to shift the display one position to the left. Place this function inside a loop with a delay to create a smooth scrolling effect[1][3][13].

2. Why does my message repeat before fully disappearing when scrolling?

This usually happens if the scroll loop is too short or the message is not padded with enough spaces. Adjust the number of scrolls or add spaces to the end of your message to ensure it fully scrolls off the display before repeating[7].

3. Can I scroll only one line of a multi-line LCD?

The built-in scroll functions move the entire display. To scroll a single line, use manual logic to display substrings of your message on the desired line, updating it in each loop iteration[11][14].

4. How can I control the scrolling speed?

Scrolling speed is controlled by the delay between each scroll step. Increase the delay for slower scrolling and decrease it for faster movement. Typical values range from 150 ms to 500 ms[13].

5. What are the advantages of using an I2C LCD for scrolling?

I2C LCDs reduce wiring complexity and free up Arduino pins. They support the same scrolling functions as parallel LCDs, making them ideal for larger projects or when pin availability is limited[10][12].

6. What should I do if my LCD shows nothing or garbled text?

Check all wiring connections, ensure the contrast potentiometer is adjusted correctly, and verify your code matches the hardware configuration. For I2C LCDs, make sure you have the correct I2C address[1][3][10].

Citations:

[1] https://www.arduino.cc/en/Tutorial/LibraryExamples/LiquidCrystalScroll/

[2] https://www.engineersgarage.com/moving-text-on-16x2-lcd-with-arduino/

[3] https://howtomechatronics.com/tutorials/arduino/lcd-tutorial/

[4] https://www.youtube.com/watch?v=3jqXUiHFXTA

[5] https://www.youtube.com/watch?v=0r_rvg1xGpY

[6] https://forum.arduino.cc/t/scroll-a-text-on-lcd-16x1/509060

[7] https://forum.arduino.cc/t/very-basic-question-about-16x2-lcd-display-scrolling/1216924

[8] https://steemit.com/utopian-io/@pakganern/iic-lcd-scrolling-text-with-arduino-tutorial

[9] https://www.youtube.com/watch?v=zbdBserL9jg

[10] https://www.youtube.com/watch?v=m6VLpSIyIt8

[11] https://www.instructables.com/Scroll-a-Single-LCD-Line-In-How-to/

[12] https://www.electromaker.io/project/view/scrolling-text-on-lcd-i2c-display-using-arduino

[13] https://arduinogetstarted.com/reference/library/lcd-scrolldisplayleft

[14] https://forums.adafruit.com/viewtopic.php?t=38982

[15] https://www.youtube.com/watch?v=tbGuXnqwYWU

[16] https://www.kelaidisplay.com/how-to-program-scrolling-lcd-display.html

[17] https://www.theengineeringprojects.com/2017/05/scrolling-text-lcd-arduino.html

[18] https://arduino.fossee.in/node/40

[19] https://www.arduino.cc/en/Tutorial/LibraryExamples/LiquidCrystalTextDirection/

[20] https://forums.adafruit.com/viewtopic.php?t=40350

[21] https://forum.inductiveautomation.com/t/how-to-make-scrolling-lcd-display-marquee/3336

[22] https://forum.arduino.cc/t/lcd-scroll-text/210755

[23] https://forums.adafruit.com/viewtopic.php?t=38982

[24] https://community.nxp.com/t5/CodeWarrior-for-MCU/Need-help-displaying-moving-text-on-a-16x2-LCD/m-p/173623

[25] https://forums.raspberrypi.com/viewtopic.php?t=220239

[26] https://arduino.stackexchange.com/questions/77190/how-do-i-make-my-lcd-screen-scroll-text-while-allowing-for-button-input

[27] https://forum.arduino.cc/t/how-can-i-scroll-part-of-text-on-lcd-screen/644931

[28] https://www.instructables.com/Scrolling-Text-Display-With-Arduino-A-to-Z-Guide/

[29] https://www.tinkercad.com/things/3rwCvL377yy-scrolling-text-displayed-in-lcd

[30] https://www.engineersgarage.com/moving-text-on-16x2-lcd-with-arduino/

[31] https://www.youtube.com/watch?v=YqjO4A81Wos

[32] https://forum.arduino.cc/t/very-basic-question-about-16x2-lcd-display-scrolling/1216924

[33] https://www.avrfreaks.net/s/topic/a5C3l000000UZzWEAW/t152144

[34] https://www.youtube.com/watch?v=--duFzywaCU

[35] https://forum.blackmagicdesign.com/viewtopic.php?f=21&t=110127

[36] https://www.youtube.com/watch?v=7SjPg9GkCJo

[37] https://www.reddit.com/r/arduino/comments/1c2u1yk/how_to_stop_my_lcd_screen_display_from_moving/

[38] https://forum.arduino.cc/t/lcd-scroll-display/397322

[39] https://focuslcds.com/journals/application-notes/how-to-scroll-text-on-a-character-display/

[40] https://electronics.stackexchange.com/questions/17991/scrolling-text-with-pic16f688-on-a-16x2-lcd

[41] https://community.st.com/t5/stm32-mcus-touchgfx-and-gui/lcd-display-shake-during-scrolling-scroll-list/td-p/194692

[42] https://www.picbasic.co.uk/forum/showthread.php?t=19709

[43] https://www.edaboard.com/threads/scrolling-text-on-lcd.215537/

[44] https://www.youtube.com/watch?v=0oMxTSDVip4

[45] https://arduino.stackexchange.com/questions/839/lcd-scrolling-down-problem

[46] https://electronics.stackexchange.com/questions/39700/in-lcd-display-scrolling-only-one-line

[47] https://www.youtube.com/watch?v=m6VLpSIyIt8

[48] https://www.gadgetronicx.com/animated-scrolling-text-lcd-8051/

[49] https://www.youtube.com/watch?v=Ay-yNX8CmMU

[50] https://www.reddit.com/r/VideoEditing/comments/hcazds/anyone_know_how_to_do_a_scrolling_text_effect/

[51] https://community.sparkfun.com/t/scrolling-on-16x2-serial-lcd-need-help-with-code/17979

[52] https://stackoverflow.com/questions/28253186/scrolling-text-from-left-to-right-on-a-mbed-using-a-lcd-display