Pixel LED 3 Digit Seven Segment token number Display board

 Pixel LED 3 Digit  Seven Segment token  number Display board

This code is for a 3-digit 7-segment display made using WS2812 (NeoPixel) LEDs, controlled by a NodeMCU ESP8266. It creates a Wi-Fi hotspot and a web page that lets the user input a number (0–999) and change the color of the digits using RGB sliders. The selected number is then shown on the LED display.

🔧 Libraries

#include <ESP8266WiFi.h>         // For Wi-Fi functionality

#include <ESP8266WebServer.h>    // For serving a web page

#include <Adafruit_NeoPixel.h>   // For controlling WS2812 LEDs

🔩 Configuration

#define LED_PIN    D6                // Data pin connected to WS2812 LEDs

#define NUM_DIGITS 3                 // 3-digit display

#define LEDS_PER_SEGMENT 4           // Each segment has 4 LEDs

#define SEGMENTS_PER_DIGIT 7         // 7 segments in a digit

#define TOTAL_LEDS (NUM_DIGITS * SEGMENTS_PER_DIGIT * LEDS_PER_SEGMENT)

💡 NeoPixel Setup

Adafruit_NeoPixel strip(TOTAL_LEDS, LED_PIN, NEO_GRB + NEO_KHZ800);

Initializes the total number of LEDs and the data format.

🔠 Digit to Segment Mapping

const byte digitMap[10][7] = { ... }

Each row represents a digit (0–9). Each column (7 total) represents a segment: F, A, B, C, D, E, G. A value of 1 means the segment is ON for that digit.

🌐 Web Server & Variables

ESP8266WebServer server(80);

int displayNumber = 0;

uint32_t currentColor = strip.Color(255, 0, 0);  // Default red

🛠️ setup() Function

    Start Serial and NeoPixel

    Start Wi-Fi in Access Point Mode

WiFi.softAP("TokenDisplay", "12345678");

Starts a Wi-Fi hotspot named TokenDisplay with password 12345678.

Setup Web Routes

    server.on("/", handleForm);         // Display HTML form

    server.on("/submit", handleSubmit); // Handle form submission

🔁 loop() Function

    Handles incoming web clients.

    Updates display only if:

        Number or color has changed.

if (displayNumber != previousNumber || currentColor != previousColor)

🌐 handleForm() – HTML Page

    Displays:

        Input box for token number

        RGB sliders

        Live color preview (<div id="colorPreview">)

    JavaScript updates the preview color in real time.

📥 handleSubmit() – Form Submission Handler

    Reads the form inputs:

        number, r, g, b

    Converts them to an integer and color

    Updates displayNumber and currentColor

    Redirects back to the form (server.sendHeader("Location", "/", true))

🔢 showNumber(int num)

    Converts number to individual digits (e.g., 456 → [4, 5, 6])

    For each digit:

        Uses digitMap to light up the correct segments

        For each segment:

            Lights all LEDs in that segment with currentColor

    Displays it using strip.show()

📊 LED Addressing Logic

Each LED is addressed as:

int startLED = (digitIndex * SEGMENTS_PER_DIGIT + segmentIndex) * LEDS_PER_SEGMENT;

This ensures LEDs for all segments and digits are lit properly.

✅ Summary

Feature Description

Wi-Fi Hotspot NodeMCU acts as access point

Web Interface Allows number and color input

3-Digit Display Shows values from 000 to 999

NeoPixel Control  Colors and brightness managed with Adafruit_NeoPixel

Live Color Preview  JavaScript updates preview as sliders move