Interfacing Arduino with ILI9341 color TFT display - JohnHau/mis GitHub Wiki

This Arduino tutorial shows how to interface the Uno board with ILI9341 TFT display. The ILI9341 TFT module contains a display controller with the same name: ILI9341. It’s a color display that uses SPI interface protocol and requires 4 or 5 control pins, it’s low cost and easy to use. The resolution of this TFT display is 240 x 320 which means it has 76800 pixels. This module works with 3.3V only and it doesn’t support 5V (not 5V tolerant). TFT: Thin-Film Transistor. SPI: Serial Peripheral Interface.

Hardware Required:

Arduino UNO board ILI9341 TFT display module 5 x 3.3k ohm resistor 5 x 2.2k ohm resistor Breadboard Jumper wires

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The ILI9341 TFT display board which is shown in the circuit diagram above has 14 pins, the first 9 pins are for the display and the other 5 pins are for the touch module. So, the display side pins which numbered from 1 to 9 are (from left to right): VCC (5V), GND (ground), CS (chip select), RST (reset), DC (or D/C: data/command), MOSI (or SDI), SCK (clock), BL (back light LED) and MISO (or SDO). MOSI: master-out slave-in. SDI: serial data in. MISO: master-in slave-out. SDO: serial data out.

As mentioned above, the ILI9341 TFT display controller works with 3.3V only (power supply and control lines). The display module is supplied with 5V that comes from the Arduino board. This module has a built-in 3.3V regulator which supplies the display controller with 3.3V from the 5V source.

All Arduino UNO board output pins are 5V, connecting a 5V pin to the ILI9341 TFT display may damage its controller. To connect the Arduino to the display module, I used voltage divider for each line which means there are 5 voltage dividers. Each voltage divider consists of 2.2k and 3.3k resistors, this drops the 5V into 3V which is sufficient.

So, the ILI9341 TFT display is connected to the Arduino board as follows (each one through voltage divider): CS pin is connected to Arduino digital pin 8, RST pin is connected to Arduino digital pin 9, D/C pin is connected to Arduino digital pin 10, MOSI pin is connected to Arduino digital pin 11, SCK pin is connected to Arduino digital pin 13.

Other pins are connected as follows: VCC pin is connected to Arduino 5V pin, GND pin is connected to Arduino GND pin, BL (LED) pin is connected to Arduino 5V pin, MISO pin is not connected.

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Full Arduino code: The following Arduino code is from Adafruit ILI9341 library (graphicstest.ino) with some modifications in order to work with the above circuit diagram.

/*************************************************** This is our GFX example for the Adafruit ILI9341 Breakout and Shield ----> http://www.adafruit.com/products/1651

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

This is a free software with NO WARRANTY. https://simple-circuit.com/

****************************************************/

#include <Adafruit_GFX.h> // include Adafruit graphics library #include <Adafruit_ILI9341.h> // include Adafruit ILI9341 TFT library

#define TFT_CS 8 // TFT CS pin is connected to arduino pin 8 #define TFT_RST 9 // TFT RST pin is connected to arduino pin 9 #define TFT_DC 10 // TFT DC pin is connected to arduino pin 10 // initialize ILI9341 TFT library Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC, TFT_RST);

void setup() { Serial.begin(9600); Serial.println("ILI9341 Test!");

tft.begin();

// read diagnostics (optional but can help debug problems) uint8_t x = tft.readcommand8(ILI9341_RDMODE); Serial.print("Display Power Mode: 0x"); Serial.println(x, HEX); x = tft.readcommand8(ILI9341_RDMADCTL); Serial.print("MADCTL Mode: 0x"); Serial.println(x, HEX); x = tft.readcommand8(ILI9341_RDPIXFMT); Serial.print("Pixel Format: 0x"); Serial.println(x, HEX); x = tft.readcommand8(ILI9341_RDIMGFMT); Serial.print("Image Format: 0x"); Serial.println(x, HEX); x = tft.readcommand8(ILI9341_RDSELFDIAG); Serial.print("Self Diagnostic: 0x"); Serial.println(x, HEX);

Serial.println(F("Benchmark Time (microseconds)"));

Serial.print(F("Screen fill ")); Serial.println(testFillScreen()); delay(500);

Serial.print(F("Text ")); Serial.println(testText()); delay(3000);

Serial.print(F("Lines ")); Serial.println(testLines(ILI9341_CYAN)); delay(500);

Serial.print(F("Horiz/Vert Lines ")); Serial.println(testFastLines(ILI9341_RED, ILI9341_BLUE)); delay(500);

Serial.print(F("Rectangles (outline) ")); Serial.println(testRects(ILI9341_GREEN)); delay(500);

Serial.print(F("Rectangles (filled) ")); Serial.println(testFilledRects(ILI9341_YELLOW, ILI9341_MAGENTA)); delay(500);

Serial.print(F("Circles (filled) ")); Serial.println(testFilledCircles(10, ILI9341_MAGENTA));

Serial.print(F("Circles (outline) ")); Serial.println(testCircles(10, ILI9341_WHITE)); delay(500);

Serial.print(F("Triangles (outline) ")); Serial.println(testTriangles()); delay(500);

Serial.print(F("Triangles (filled) ")); Serial.println(testFilledTriangles()); delay(500);

Serial.print(F("Rounded rects (outline) ")); Serial.println(testRoundRects()); delay(500);

Serial.print(F("Rounded rects (filled) ")); Serial.println(testFilledRoundRects()); delay(500);

Serial.println(F("Done!"));

}

void loop(void) { for(uint8_t rotation=0; rotation<4; rotation++) { tft.setRotation(rotation); testText(); delay(1000); } }

unsigned long testFillScreen() { unsigned long start = micros(); tft.fillScreen(ILI9341_BLACK); tft.fillScreen(ILI9341_RED); tft.fillScreen(ILI9341_GREEN); tft.fillScreen(ILI9341_BLUE); tft.fillScreen(ILI9341_BLACK); return micros() - start; }

unsigned long testText() { tft.fillScreen(ILI9341_BLACK); unsigned long start = micros(); tft.setCursor(0, 0); tft.setTextColor(ILI9341_WHITE); tft.setTextSize(1); tft.println("Hello World!"); tft.setTextColor(ILI9341_YELLOW); tft.setTextSize(2); tft.println(1234.56); tft.setTextColor(ILI9341_RED); tft.setTextSize(3); tft.println(0xDEADBEEF, HEX); tft.println(); tft.setTextColor(ILI9341_GREEN); tft.setTextSize(5); tft.println("Groop"); tft.setTextSize(2); tft.println("I implore thee,"); tft.setTextSize(1); tft.println("my foonting turlingdromes."); tft.println("And hooptiously drangle me"); tft.println("with crinkly bindlewurdles,"); tft.println("Or I will rend thee"); tft.println("in the gobberwarts"); tft.println("with my blurglecruncheon,"); tft.println("see if I don't!"); return micros() - start; }

unsigned long testLines(uint16_t color) { unsigned long start, t; int x1, y1, x2, y2, w = tft.width(), h = tft.height();

tft.fillScreen(ILI9341_BLACK);

x1 = y1 = 0; y2 = h - 1; start = micros(); for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color); x2 = w - 1; for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color); t = micros() - start; // fillScreen doesn't count against timing

tft.fillScreen(ILI9341_BLACK);

x1 = w - 1; y1 = 0; y2 = h - 1; start = micros(); for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color); x2 = 0; for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color); t += micros() - start;

tft.fillScreen(ILI9341_BLACK);

x1 = 0; y1 = h - 1; y2 = 0; start = micros(); for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color); x2 = w - 1; for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color); t += micros() - start;

tft.fillScreen(ILI9341_BLACK);

x1 = w - 1; y1 = h - 1; y2 = 0; start = micros(); for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color); x2 = 0; for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);

return micros() - start; }

unsigned long testFastLines(uint16_t color1, uint16_t color2) { unsigned long start; int x, y, w = tft.width(), h = tft.height();

tft.fillScreen(ILI9341_BLACK); start = micros(); for(y=0; y<h; y+=5) tft.drawFastHLine(0, y, w, color1); for(x=0; x<w; x+=5) tft.drawFastVLine(x, 0, h, color2);

return micros() - start; }

unsigned long testRects(uint16_t color) { unsigned long start; int n, i, i2, cx = tft.width() / 2, cy = tft.height() / 2;

tft.fillScreen(ILI9341_BLACK); n = min(tft.width(), tft.height()); start = micros(); for(i=2; i<n; i+=6) { i2 = i / 2; tft.drawRect(cx-i2, cy-i2, i, i, color); }

return micros() - start; }

unsigned long testFilledRects(uint16_t color1, uint16_t color2) { unsigned long start, t = 0; int n, i, i2, cx = tft.width() / 2 - 1, cy = tft.height() / 2 - 1;

tft.fillScreen(ILI9341_BLACK); n = min(tft.width(), tft.height()); for(i=n; i>0; i-=6) { i2 = i / 2; start = micros(); tft.fillRect(cx-i2, cy-i2, i, i, color1); t += micros() - start; // Outlines are not included in timing results tft.drawRect(cx-i2, cy-i2, i, i, color2); }

return t; }

unsigned long testFilledCircles(uint8_t radius, uint16_t color) { unsigned long start; int x, y, w = tft.width(), h = tft.height(), r2 = radius * 2;

tft.fillScreen(ILI9341_BLACK); start = micros(); for(x=radius; x<w; x+=r2) { for(y=radius; y<h; y+=r2) { tft.fillCircle(x, y, radius, color); } }

return micros() - start; }

unsigned long testCircles(uint8_t radius, uint16_t color) { unsigned long start; int x, y, r2 = radius * 2, w = tft.width() + radius, h = tft.height() + radius;

// Screen is not cleared for this one -- this is // intentional and does not affect the reported time. start = micros(); for(x=0; x<w; x+=r2) { for(y=0; y<h; y+=r2) { tft.drawCircle(x, y, radius, color); } }

return micros() - start; }

unsigned long testTriangles() { unsigned long start; int n, i, cx = tft.width() / 2 - 1, cy = tft.height() / 2 - 1;

tft.fillScreen(ILI9341_BLACK); n = min(cx, cy); start = micros(); for(i=0; i<n; i+=5) { tft.drawTriangle( cx , cy - i, // peak cx - i, cy + i, // bottom left cx + i, cy + i, // bottom right tft.color565(0, 0, i)); }

return micros() - start; }

unsigned long testFilledTriangles() { unsigned long start, t = 0; int i, cx = tft.width() / 2 - 1, cy = tft.height() / 2 - 1;

tft.fillScreen(ILI9341_BLACK); start = micros(); for(i=min(cx,cy); i>10; i-=5) { start = micros(); tft.fillTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i, tft.color565(0, i, i)); t += micros() - start; tft.drawTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i, tft.color565(i, i, 0)); }

return t; }

unsigned long testRoundRects() { unsigned long start; int w, i, i2, cx = tft.width() / 2 - 1, cy = tft.height() / 2 - 1;

tft.fillScreen(ILI9341_BLACK); w = min(tft.width(), tft.height()); start = micros(); for(i=0; i<w; i+=6) { i2 = i / 2; tft.drawRoundRect(cx-i2, cy-i2, i, i, i/8, tft.color565(i, 0, 0)); }

return micros() - start; }

unsigned long testFilledRoundRects() { unsigned long start; int i, i2, cx = tft.width() / 2 - 1, cy = tft.height() / 2 - 1;

tft.fillScreen(ILI9341_BLACK); start = micros(); for(i=min(tft.width(), tft.height()); i>20; i-=6) { i2 = i / 2; tft.fillRoundRect(cx-i2, cy-i2, i, i, i/8, tft.color565(0, i, 0)); }

return micros() - start; }

The following video shows my simple hardware circuit test:

And this one shows Proteus simulation (not perfect result!): Note that Proteus simulation circuit is not the same as real hardware circuit, project hardware circuit diagram is shown above.

Proteus simulation file download link is below, use version 8.6 or higher to open it: Arduino and ILI9341 TFT Proteus simulation

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