ra8875_bitmap_fast.ino

#include <Adafruit_GFX.h>    // Core graphics library
#include <SPI.h>
#include <Wire.h>
#include <SD.h>
#include "Adafruit_RA8875.h"
#include <Adafruit_STMPE610.h>
#define sd_cs 6                          // using ethernet shield sd

// Library only supports hardware SPI at this time
// Connect SCLK to UNO Digital #13 (Hardware SPI clock)
// Connect MISO to UNO Digital #12 (Hardware SPI MISO)
// Connect MOSI to UNO Digital #11 (Hardware SPI MOSI)
#define RA8875_INT 3
#define RA8875_CS 10
#define RA8875_RESET 9

Adafruit_RA8875 tft = Adafruit_RA8875(RA8875_CS, RA8875_RESET);

void setup () {
  Serial.begin(9600);

  if (!SD.begin(sd_cs))
  {
    Serial.println("initialization failed!");
    return;
  }

  Serial.println("initialization done.");

  Serial.println("RA8875 start");

  /* Initialize the display using 'RA8875_480x80', 'RA8875_480x128', 'RA8875_480x272' or 'RA8875_800x480' */
  if (!tft.begin(RA8875_800x480)) {
    Serial.println("RA8875 Not Found!");
    while (1);
  }

  Serial.println("Found RA8875");

  tft.displayOn(true);
  tft.GPIOX(true);      // Enable TFT - display enable tied to GPIOX
  tft.PWM1config(true, RA8875_PWM_CLK_DIV1024); // PWM output for backlight
  tft.PWM1out(255);

  Serial.print("(");
  Serial.print(tft.width());
  Serial.print(", ");
  Serial.print(tft.height());
  Serial.println(")");
  tft.graphicsMode();                 // go back to graphics mode
  tft.fillScreen(RA8875_BLACK);
  tft.graphicsMode();
  bmpDraw("parrot.bmp", 0, 0);
}

void loop()
{
}

// This function opens a Windows Bitmap (BMP) file and
// displays it at the given coordinates.  It's sped up
// by reading many pixels worth of data at a time
// (rather than pixel by pixel).  Increasing the buffer
// size takes more of the Arduino's precious RAM but
// makes loading a little faster.  20 pixels seems a
// good balance.

#define BUFFPIXEL 20

void bmpDraw(const char *filename, int x, int y) {
  File     bmpFile;
  int      bmpWidth, bmpHeight;   // W+H in pixels
  uint8_t  bmpDepth;              // Bit depth (currently must be 24)
  uint32_t bmpImageoffset;        // Start of image data in file
  uint32_t rowSize;               // Not always = bmpWidth; may have padding
  uint8_t  sdbuffer[3*BUFFPIXEL]; // pixel in buffer (R+G+B per pixel)
  uint16_t lcdbuffer[BUFFPIXEL];  // pixel out buffer (16-bit per pixel)
  uint8_t  buffidx = sizeof(sdbuffer); // Current position in sdbuffer
  boolean  goodBmp = false;       // Set to true on valid header parse
  boolean  flip    = true;        // BMP is stored bottom-to-top
  int      w, h, row, col, xpos, ypos;
  uint8_t  r, g, b;
  uint32_t pos = 0, startTime = millis();
  uint8_t  lcdidx = 0;

  if((x >= tft.width()) || (y >= tft.height())) return;

  Serial.println();
  Serial.print(F("Loading image '"));
  Serial.print(filename);
  Serial.println('\'');

  // Open requested file on SD card
  if ((bmpFile = SD.open(filename)) == false) {
    Serial.println(F("File not found"));
    return;
  }

  // Parse BMP header
  if(read16(bmpFile) == 0x4D42) { // BMP signature
    Serial.println(F("File size: "));
    Serial.println(read32(bmpFile));
    (void)read32(bmpFile); // Read & ignore creator bytes
    bmpImageoffset = read32(bmpFile); // Start of image data
    Serial.print(F("Image Offset: "));
    Serial.println(bmpImageoffset, DEC);

    // Read DIB header
    Serial.print(F("Header size: "));
    Serial.println(read32(bmpFile));
    bmpWidth  = read32(bmpFile);
    bmpHeight = read32(bmpFile);

    if(read16(bmpFile) == 1) { // # planes -- must be '1'
      bmpDepth = read16(bmpFile); // bits per pixel
      Serial.print(F("Bit Depth: "));
      Serial.println(bmpDepth);
      if((bmpDepth == 24) && (read32(bmpFile) == 0)) { // 0 = uncompressed
        goodBmp = true; // Supported BMP format -- proceed!
        Serial.print(F("Image size: "));
        Serial.print(bmpWidth);
        Serial.print('x');
        Serial.println(bmpHeight);

        // BMP rows are padded (if needed) to 4-byte boundary
        rowSize = (bmpWidth * 3 + 3) & ~3;

        // If bmpHeight is negative, image is in top-down order.
        // This is not canon but has been observed in the wild.
        if(bmpHeight < 0) {
          bmpHeight = -bmpHeight;
          flip      = false;
        }

        // Crop area to be loaded
        w = bmpWidth;
        h = bmpHeight;
        if((x+w-1) >= tft.width())  w = tft.width()  - x;
        if((y+h-1) >= tft.height()) h = tft.height() - y;

        // Set TFT address window to clipped image bounds
        ypos = y;
        for (row=0; row<h; row++) { // For each scanline...
          // Seek to start of scan line.  It might seem labor-
          // intensive to be doing this on every line, but this
          // method covers a lot of gritty details like cropping
          // and scanline padding.  Also, the seek only takes
          // place if the file position actually needs to change
          // (avoids a lot of cluster math in SD library).
          if(flip) // Bitmap is stored bottom-to-top order (normal BMP)
            pos = bmpImageoffset + (bmpHeight - 1 - row) * rowSize;
          else     // Bitmap is stored top-to-bottom
            pos = bmpImageoffset + row * rowSize;

          if (bmpFile.position() != pos) { // Need seek?
            bmpFile.seek(pos);
            buffidx = sizeof(sdbuffer); // Force buffer reload
          }
          xpos = x;
          for (col=0; col<w; col++) { // For each column...
            // Time to read more pixel data?
            if (buffidx >= sizeof(sdbuffer)) { // Indeed
              // Push LCD buffer to the display first
              if(lcdidx > 0) {
                tft.drawPixels(lcdbuffer, lcdidx, xpos, ypos);
                xpos += lcdidx;
                lcdidx = 0;
              }

              bmpFile.read(sdbuffer, sizeof(sdbuffer));
              buffidx = 0; // Set index to beginning
            }

            // Convert pixel from BMP to TFT format
            b = sdbuffer[buffidx++];
            g = sdbuffer[buffidx++];
            r = sdbuffer[buffidx++];
            lcdbuffer[lcdidx++] = color565(r,g,b);
            if (lcdidx >= sizeof(lcdbuffer) || (xpos - x + lcdidx) >= w) {
              tft.drawPixels(lcdbuffer, lcdidx, xpos, ypos);
              lcdidx = 0;
              xpos += lcdidx;
            }
          } // end pixel
            ypos++;
        } // end scanline

        // Write any remaining data to LCD
        if(lcdidx > 0) {
          tft.drawPixels(lcdbuffer, lcdidx, xpos, ypos);
          xpos += lcdidx;
        }

        Serial.print(F("Loaded in "));
        Serial.print(millis() - startTime);
        Serial.println(" ms");

      } // end goodBmp
    }
  }

  bmpFile.close();
  if(!goodBmp) Serial.println(F("BMP format not recognized."));

}

// These read 16- and 32-bit types from the SD card file.
// BMP data is stored little-endian, Arduino is little-endian too.
// May need to reverse subscript order if porting elsewhere.

uint16_t read16(File f) {
  uint16_t result;
  ((uint8_t *)&result)[0] = f.read(); // LSB
  ((uint8_t *)&result)[1] = f.read(); // MSB
  return result;
}

uint32_t read32(File f) {
  uint32_t result;
  ((uint8_t *)&result)[0] = f.read(); // LSB
  ((uint8_t *)&result)[1] = f.read();
  ((uint8_t *)&result)[2] = f.read();
  ((uint8_t *)&result)[3] = f.read(); // MSB
  return result;
}

uint16_t color565(uint8_t r, uint8_t g, uint8_t b) {
  return ((r & 0xF8) << 8) | ((g & 0xFC) << 3) | (b >> 3);
}

byte decToBcd(byte val){
  // Convert normal decimal numbers to binary coded decimal
  return ( (val/10*16) + (val%10) );
}