The **CFAG1602A-RGL-JP** is a character Liquid Crystal Display (LCD) module manufactured by Crystalfontz. It is designed for displaying text, typically consisting of 16 characters across 2 lines. Below is a breakdown of its core electronic specifications and features. --- ### 1. General Specifications | Feature | Details | | :--- | :--- | | **Display Format** | 16 Characters x 2 Lines | | **LCD Mode** | STN Gray, Positive, Reflective | | **Interface** | 6800 4-bit or 8-bit Parallel | | **Controller** | ST7066U (or compatible) | | **Character Set** | English / Japanese (Katakana) | --- ### 2. Electrical Characteristics These parameters are critical for ensuring the display operates without damage to the logic or the liquid crystal material. * **Supply Voltage ($V_{DD}$):** Typically **5.0V** (range of 4.5V to 5.5V). * **Supply Current ($I_{DD}$):** Approximately **1.2mA to 2.0mA** (very low power since it is reflective). * **LCD Driving Voltage ($V_{DD} - V_O$):** Roughly **4.5V at 25°C**. This is adjusted via a potentiometer to control contrast. --- ### 3. Pinout Configuration The module uses a standard 16-pin interface (though reflective models may only utilize 14 pins if no backlight is present). | Pin No. | Symbol | Function | | :--- | :--- | :--- | | 1 | VSS | Ground (0V) | | 2 | VDD | Supply Voltage (+5V) | | 3 | VO | Contrast Adjustment | | 4 | RS | Register Select (High: Data / Low: Instruction) | | 5 | R/W | Read/Write (High: Read / Low: Write) | | 6 | E | Enable Signal | | 7-14 | DB0-DB7 | Data Bus Lines | --- ### 4. Key Electronic Components 1. **ST7066U Controller:** This is the "brain" of the module. It handles the DDRAM (Display Data RAM) which stores the characters and the CGROM (Character Generator ROM) which contains the font bitmaps. 2. **Reflective Polarizer:** Unlike transmissive displays, this model uses a **Reflective** rear polarizer. It relies on ambient light to be visible and does not have an internal LED backlight. This makes it ideal for high-sunlight environments and ultra-low power applications. 3. **Temperature Compensation:** The contrast of the STN fluid changes with temperature. In many circuits, a thermistor or a manual potentiometer is used on **Pin 3 (VO)** to maintain visibility as the environment warms or cools. --- ### 5. Interfacing Example (Arduino/C++) To drive this part, you would typically use a standard Hitachi HD44780 compatible library. ```cpp #include // Initialize the library with the numbers of the interface pins // RS, E, D4, D5, D6, D7 LiquidCrystal lcd(12, 11, 5, 4, 3, 2); void setup() { lcd.begin(16, 2); lcd.print("Hello, World!"); } void loop() { // Cursor moves to line 1, column 0 lcd.setCursor(0, 1); lcd.print("CFAG1602A Test"); } ``` ---