Futaba NAGP1250 Arduino Library

A high-performance Arduino/PlatformIO driver for the Futaba NAGP1250 Vacuum Fluorescent Display (VFD).

This library is a C++ port of the MicroPython driver by Catlin Kintsugi, optimized for speed and hardware flow control.

Features

• High-Speed Graphics: Logic-optimized for streaming animations (circles, lines, boxes).
• Hardware Flow Control: Supports the SBUSY pin for maximum frame rate without corruption.
• Text & Windows: Full support for hardware text layers, windowing, and scrolling.
• Robust SPI: Uses LSBFIRST and correct timing to ensure glitch-free operation on ESP32 and other MCUs.

Wiring (ESP32 Example)

VFD Pin	ESP32 Pin	Description
SIN	GPIO 23	MOSI (Data)
CLK	GPIO 18	SCK (Clock)
RES	GPIO 5	Reset
BSY	GPIO 35	SBUSY (Flow Control)
GND	GND	Ground
VCC	5V	Power

Note: The SBUSY connection is highly recommended. If connected, the library automatically detects it and switches to a high-speed polling mode, allowing for smooth 30+ FPS animations. If disconnected, it falls back to safe timing delays (~400µs per byte).

Getting Started

PlatformIO

Add to your platformio.ini:

lib_deps =
    FutabaNAGP1250

Basic Usage

#include <FutabaNAGP1250.h>

// Pin Definitions
#define PIN_MOSI  23
#define PIN_SCK   18
#define PIN_RESET 5
#define PIN_SBUSY 35

FutabaNAGP1250 vfd(SPI, PIN_RESET, PIN_SBUSY);

void setup() {
    SPI.begin(PIN_SCK, -1, PIN_MOSI, -1);
    
    // Initialize VFD (140x32 resolution)
    vfd.begin();
    vfd.setLuminance(8); // Max brightness
    
    // Text
    vfd.setCursorPosition(0, 0);
    vfd.writeText("Hello World!");
    
    // Graphics
    std::vector<uint8_t> bitmap(140 * 32 / 8, 0); // Packed buffer
    // ... draw to bitmap ...
    vfd.displayGraphicImage(bitmap, 140, 32);
}

void loop() {
}

Streaming & Performance

For video or fast animations, ensure you connect the SBUSY pin. The library utilizes a tight polling loop to synchronize perfectly with the VFD's processing speed, eliminating buffer overflows and visual corruption while maximizing throughput.

Advanced Examples

Video Streaming (Node.js + ESP32)

For a high-performance video streaming demonstration (30FPS with compression and dithering), check out the companion project: FutabaNAGP1250_Stream