### CFAG1602A-RBC-JP Electronic Specifications The **CFAG1602A-RBC-JP** is a 16x2 character LCD module manufactured by Crystalfontz. This specific model features a **Red** LED backlight and a **Blue** background (STN Negative Blue). --- ### 1. Key Technical Specifications Below are the primary electrical and physical parameters for this module: | Parameter | Specification | | :--- | :--- | | **Display Type** | Character LCD (16 characters x 2 lines) | | **LCD Technology** | STN Negative, Blue | | **Backlight** | Red LED | | **Controller** | Sitronix ST7066U (or equivalent) | | **Interface** | 4-bit or 8-bit Parallel | | **Operating Voltage (Vdd)** | 5.0V (Typical) | | **Input Logic High** | 0.7 Vdd to Vdd | | **Input Logic Low** | -0.3V to 0.6V | --- ### 2. Pinout Configuration The module uses a standard 16-pin interface common to most character LCDs. | Pin | Symbol | Function | | :--- | :--- | :--- | | 1 | Vss | Ground (0V) | | 2 | Vdd | Supply Voltage (+5V) | | 3 | Vo | Contrast Adjustment | | 4 | RS | Register Select (Command/Data) | | 5 | R/W | Read/Write Select | | 6 | E | Enable Signal | | 7-14 | DB0-DB7 | Data Bus Lines | | 15 | A (LED+) | Backlight Anode (+5V typically via resistor) | | 16 | K (LED-) | Backlight Cathode (Ground) | --- ### 3. Controller & Programming The heart of this module is the **ST7066U** controller. It is industry-standard and compatible with the HD44780 instruction set. * **Initialization:** Requires a specific power-on sequence (Function Set, Display ON/OFF, Entry Mode Set). * **Instruction Set:** Supports clear display, cursor home, shift display, and custom character creation (CGRAM). * **Contrast Control:** Pin 3 (Vo) usually requires a 10k-20k Ohm potentiometer connected between Vdd and Vss to adjust the visibility of the characters. --- ### 4. Backlight Requirements Because this is a **Negative Blue** display, the characters are transparent and the background is opaque blue. The red backlight shines through the characters. * **Forward Voltage:** Typically ~3.5V to 5.0V for the LED. * **Current Limiting:** A series resistor is mandatory to prevent burning out the LEDs if your supply is exactly 5V and the LED forward voltage is lower.