2004A LCD Character Display Module 20x4 5V Blue Backlight
2004A LCD Character Display Module 20x4 5V Blue Backlight
2004A LCD Character Display Module — 20×4 Lines, 5V, Blue LED Backlight
The 2004A (J204A) LCD Character Display Module is a versatile 20-column × 4-row alphanumeric screen ideal for microcontroller projects, Arduino builds, Raspberry Pi setups, DIY electronics, lab instruments, and embedded systems. Running at a clean 5V supply, it delivers crisp, easy-to-read characters on a vivid blue LED backlit panel with white text — perfect for both indoor enclosures and prototyping breadboards.
Key Features
- 20 columns × 4 rows of character display — plenty of space for sensor readings, menus, status messages, and data output
- 5V operating voltage — compatible with Arduino, Raspberry Pi, PIC, AVR, STM32, and most common microcontrollers
- Blue LED backlight with white characters for high-contrast readability in low-light environments
- Standard 16-pin HD44780-compatible interface — works with virtually all LCD libraries (I2C adapter compatible)
- LCM (Liquid Crystal Module) construction — durable, compact, and easy to mount in project enclosures
- Adjustable contrast via onboard potentiometer (or trimpot on I2C backpack)
- Wide operating temperature range — reliable in workshop and lab environments
Typical Applications
- Arduino & Raspberry Pi hobby projects
- DIY weather stations and sensor dashboards
- Home automation control panels
- Industrial prototyping and embedded system displays
- Educational electronics kits and STEM labs
- Custom clocks, timers, and measurement displays
Specifications
- Model: 2004A / J204A
- Display Format: 20 characters × 4 lines
- Supply Voltage: 5V DC
- Backlight Color: Blue (LED)
- Character Color: White
- Interface: 16-pin parallel (HD44780-compatible)
- Controller: HD44780 or equivalent
- Vendor: Qme
For guidance on electronics safety and best practices when working with low-voltage display modules, visit the U.S. Consumer Product Safety Commission (CPSC).
Frequently Asked Questions
Q: What microcontrollers are compatible with the 2004A LCD Character Display Module?
A: The 2004A LCD module uses the industry-standard HD44780-compatible parallel interface, making it compatible with Arduino (Uno, Mega, Nano), Raspberry Pi (via I2C backpack), PIC, AVR, STM32, ESP8266, ESP32, and most other 5V or 3.3V (with logic level shifting) microcontrollers. Popular libraries such as the Arduino LiquidCrystal and LiquidCrystal_I2C libraries support it out of the box.
Q: Can I use the 2004A LCD module with an I2C adapter?
A: Yes. While the module itself uses a 16-pin parallel interface, you can attach a widely available I2C backpack module (PCF8574-based) to reduce wiring to just 4 pins (VCC, GND, SDA, SCL). This is a popular approach for Arduino and Raspberry Pi builds where GPIO pins are limited.
Q: What does "20×4" mean on this LCD display module?
A: "20×4" refers to the display grid: 20 character columns across and 4 rows of text. This gives you 80 total character positions — enough to display multi-line sensor readings, status messages, menu options, and custom data all at once, making it ideal for more information-rich projects compared to smaller 16×2 screens.
Q: How do I adjust the contrast on the 2004A LCD module?
A: The contrast is adjusted by varying the voltage on pin 3 (VEE/V0). On most setups, a 10kΩ potentiometer connected between VCC and GND with the wiper going to pin 3 allows you to dial in perfect contrast. If using an I2C backpack, there is usually a small onboard trimpot you can turn with a small screwdriver.