Using SD card to load image on to display. Must use 2.8…3.3V external power supply or resistive level sifter. Remove SD card before connecting to USB and transferring program to Arduino.
Connect external power supply to 5V output pin. It does not harm Arduino in any way. Remove power supply connection before connecting USB or it will harm computer.
Arduino connection
- SCLK (Serial Clock) to pin D13
- MISO (Master Input ← Slave Output) to pin D12
- MOSI (Master Output → Slave Input) to pin D11
- TFT_CS (TFT display Chip Select) to pin D10
- D/C (Data/Control) to pin D9
- Reset to pin D8
- SD_CS (SD card Chip Select) to pin D4
Adafruits example code for reading image from SD card and display it on screen. It is licensed with MIT license. Image must be in root directory in BMP format. SD card must be formatted to FAT16 or FAT32 format.
/*************************************************** This is an example sketch for the Adafruit 2.2" SPI display. This library works with the Adafruit 2.2" TFT Breakout w/SD card ----> http://www.adafruit.com/products/1480 Check out the links above for our tutorials and wiring diagrams These displays use SPI to communicate, 4 or 5 pins are required to interface (RST is optional) Adafruit invests time and resources providing this open source code, please support Adafruit and open-source hardware by purchasing products from Adafruit! Written by Limor Fried/Ladyada for Adafruit Industries. MIT license, all text above must be included in any redistribution ****************************************************/ #include <Adafruit_GFX.h> // Core graphics library #include "Adafruit_ILI9340.h" // Hardware-specific library #include <SPI.h> #include <SD.h> #if defined(__SAM3X8E__) #undef __FlashStringHelper::F(string_literal) #define F(string_literal) string_literal #endif // TFT display and SD card will share the hardware SPI interface. // Hardware SPI pins are specific to the Arduino board type and // cannot be remapped to alternate pins. For Arduino Uno, // Duemilanove, etc., pin 11 = MOSI, pin 12 = MISO, pin 13 = SCK. #define TFT_RST 8 #define TFT_DC 9 #define TFT_CS 10 #define SD_CS 4 Adafruit_ILI9340 tft = Adafruit_ILI9340(TFT_CS, TFT_DC, TFT_RST); void setup(void) { Serial.begin(9600); Serial.print("Initializing SD card..."); if (!SD.begin(SD_CS)) { Serial.println("failed!"); return; } Serial.println("OK!"); tft.begin(); tft.fillScreen(ILI9340_BLUE); bmpDraw("myy.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(char *filename, uint16_t x, uint16_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; }