showLittleFSImage.ino File Reference

Functions
void	showLittleFSImage ()

Variables
int	cnti = 0
	Displays an image stored on the ESP8266 using the LittleFS file system.

Function Documentation

showLittleFSImage()

void showLittleFSImage

(

)

{
    // Open the image file from LittleFS
    a = LittleFS.open(bin, "r"); // Open every time?
 
    if (!a)
    {
        // If no file is found, go to the next image
        imageToUse++;
        // FastLED.showColor(CRGB::Blue); // Display error color (optional)
        // Serial.println("Code Blue - no file found!");
    }
    else
    {
        size_t size = a.size(); // Get file size
 
        // Check if the image size is larger than the max allowed
        if (size > maxPX)
        {
            // Display error if the image is too large
            FastLED.showColor(CRGB::Blue); // Show blue color as error indicator
            imageToUse++;
        }
        else
        {
            // Calculate the number of pixels across based on the file size
            pxAcross = int(size / pxDown); // Should be an integer
 
            // Read image data into message1Data buffer
            a.read(message1Data, size);
 
            cnti++;
            if (cnti >= pxDown)
            {
                cnti = 0;
            }
 
            // Close the file after reading
            a.close();
        }
    }
 
    // Initialize counter for reading pixel data
    int counter = 0;
 
    // Loop through the pixels to display the image
    for (int j = 0; j < pxAcross; j++)
    {
        for (int i = 0; i < pxDown; i++)
        {
            byte X = message1Data[counter++]; // Get pixel data
 
            // Decompress and assign color values
            byte R1 = (X & 0xE0); // Extract Red value (3 bits)
            leds[i].r = R1;
            byte G1 = ((X << 3) & 0xE0); // Extract Green value (3 bits)
            leds[i].g = G1;
            byte M1 = (X << 6); // Extract Blue value (2 bits)
            leds[i].b = M1;
 
            // Optional: Print RGB values for debugging
            // Serial.print(R1); Serial.print(", "); Serial.print(G1); Serial.print(", "); Serial.println(M1);
        }
 
        // Display the current row of pixels on the LED strip
        FastLED.show();
 
        // Optional delay depending on the number of LEDs
        if (NUM_LEDS < 72)
        {
            // FastLED.delay(1); // For 160MHz clock - only applies to APA102 Strip
        }
        else
        {
            // No delay needed for larger LED strips
        }
    }
}

References a, bin, cnti, G1, imageToUse, leds, M1, maxPX, message1Data, NUM_LEDS, pxAcross, pxDown, R1, and X.

Referenced by loop().

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Variable Documentation

cnti

int cnti = 0

Displays an image stored on the ESP8266 using the LittleFS file system.

This function loads an image from the LittleFS file system, checks its size, and displays the image pixel-by-pixel on an LED strip using FastLED. The image is stored in a compressed format and is decompressed into RGB values.

The function handles different cases such as missing files and oversized images. It iterates through the pixels to display the image across the LED strip.

Note

The image file should be stored in LittleFS as a binary file.

Todo

Add converter from "bin" to filename from listDir() or implement image index to access the correct image.

Todo

Test if this version can work concurrently with older image display logic.

Returns

void

Referenced by showLittleFSImage().