TFT Display – Bilder Über SD Karte anzeigen

Auf dem TFT Display, welches ich im letzten Post vorgestellt habe, kann man ebenfalls Bilder anzeigen lassen.

Hier mal ein Beispiel:

spongii <3

Wichtig ist, dass:

  • Die Bilder im *.bmp – Format vorliegen
  • Das Format sollte 128 x 160 Pixel betragen
  • Die Bilder müssen im /root Verzeichnis der SD Karte sein
  • Die SD Karte sollte FAT32 formatiert sein
  • Die Bilder sollten im 24BIT Farbformat vorliegen

Hier die Schaltung:

Leonardo Display
10 CS
9 DC
8 RES
SDA SDA
SCL SCL
5V VCC
GND GND
4 SD-CS
ICSP-1 MISO
ICSP-3 SCLK
ICSP-4 MOSI

Programmcode:

#include <Adafruit_GFX.h>    // Core graphics library
#include <Adafruit_ST7735.h> // Hardware-specific library
#include <SPI.h>
#include <SD.h>
#define SD_CS    4  // Chip select line for SD card
#define TFT_CS  10  // Chip select line for TFT display
#define TFT_DC   9  // Data/command line for TFT
#define TFT_RST  8  // Reset line for TFT (or connect to +5V)

Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, SDA, SCL, TFT_RST);

void setup(void) {
Serial.begin(9600);
tft.initR(INITR_REDTAB);
Serial.print(„Initializing SD card…“);
if (!SD.begin(SD_CS)) {
Serial.println(„failed!“);
return;
}
Serial.println(„OK!“);
}

void loop() {

bmpDraw(„1.bmp“, 0, 0);
delay(4000);
bmpDraw(„2.bmp“, 0, 0);
delay(4000);
bmpDraw(„3.bmp“, 0, 0);
delay(4000);
bmpDraw(„4.bmp“, 0, 0);
delay(4000);
}

#define BUFFPIXEL 20

void bmpDraw(char *filename, uint8_t x, uint8_t 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 buffer (R+G+B 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;
uint8_t  r, g, b;
uint32_t pos = 0, startTime = millis();

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

Serial.println();
Serial.print(„Loading image ‚“);
Serial.print(filename);
Serial.println(‚\“);

// Open requested file on SD card
if ((bmpFile = SD.open(filename)) == NULL) {
Serial.print(„File not found“);
return;
}

// Parse BMP header
if(read16(bmpFile) == 0x4D42) { // BMP signature
Serial.print(„File size: „);
Serial.println(read32(bmpFile));
(void)read32(bmpFile); // Read & ignore creator bytes
bmpImageoffset = read32(bmpFile); // Start of image data
Serial.print(„Image Offset: „);
Serial.println(bmpImageoffset, DEC);
// Read DIB header
Serial.print(„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(„Bit Depth: „);
Serial.println(bmpDepth);
if((bmpDepth == 24) && (read32(bmpFile) == 0)) { // 0 = uncompressed

goodBmp = true; // Supported BMP format — proceed!
Serial.print(„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
tft.setAddrWindow(x, y, x+w-1, y+h-1);

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
}

for (col=0; col<w; col++) { // For each pixel…
// Time to read more pixel data?
if (buffidx >= sizeof(sdbuffer)) { // Indeed
bmpFile.read(sdbuffer, sizeof(sdbuffer));
buffidx = 0; // Set index to beginning
}

// Convert pixel from BMP to TFT format, push to display
b = sdbuffer[buffidx++];
g = sdbuffer[buffidx++];
r = sdbuffer[buffidx++];
tft.pushColor(tft.Color565(r,g,b));
} // end pixel
} // end scanline
Serial.print(„Loaded in „);
Serial.print(millis() – startTime);
Serial.println(“ ms“);
} // end goodBmp
}
}

bmpFile.close();
if(!goodBmp) Serial.println(„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;
}

 

Advertisements

Kommentar verfassen

Trage deine Daten unten ein oder klicke ein Icon um dich einzuloggen:

WordPress.com-Logo

Du kommentierst mit Deinem WordPress.com-Konto. Abmelden / Ändern )

Twitter-Bild

Du kommentierst mit Deinem Twitter-Konto. Abmelden / Ändern )

Facebook-Foto

Du kommentierst mit Deinem Facebook-Konto. Abmelden / Ändern )

Google+ Foto

Du kommentierst mit Deinem Google+-Konto. Abmelden / Ändern )

Verbinde mit %s

%d Bloggern gefällt das: