Arduino Interface with ST7789 Color TFT Display

1 Comment / By Simple Projects / June 5, 2024

Adding a display to an embedded system can significantly enhance its functionality by providing visual feedback and an interactive user interface. This tutorial shows how to interface Arduino development board with ST7789 color TFT display.

Abbreviations:
TFT: Thin-Film Transistor.
SPI: Serial Peripheral Interface.
IPS: In-Plane Switching.
MOSI: Master Out Slave In.
MISO: Master In Slave Out.
DIY: Do-It-Yourself

The ST7789 Color TFT Display:
The ST7789 is a display controller/driver chip for 262K-color, graphic type TFT-LCD, originally manufactured by Sitronix Technology Corp ( —ST7789 datasheet— ).
The ST7789 display is commonly used in projects involving microcontrollers like Arduino, ESP32, and Raspberry Pi. Here are some key features and aspects of the ST7789 TFT display:

Display Controller: This display is based on a controller chip of the same name, ST7789 (or, ST7789V, ST7789VW), providing an interface between the master device and the display panel.
Color TFT-LCD: It is specifically designed for color displays, supporting 16-bit (65,536 colors) and 18-bit (262,144 colors) color modes, providing rich color display capabilities.
Resolution: The ST7789 displays come with different resolutions (320×240 pixel, 240×240 pixel…) supporting landscape and portrait orientations. Common resolutions are 240×240 pixels and 240×320 pixels.
Communication Interface: It usually interfaces with microcontrollers or other devices using SPI (Serial Peripheral Interface).
Supported Operations: The ST7789 TFT display supports standard display operations such as drawing pixels, lines, rectangles, and displaying images.
Display Orientation: Can be rotated to multiple orientations (0, 90, 180, 270 degrees) through software commands.
Low Power Consumption: It is designed to be power-efficient, suitable for battery-powered or low-power devices.
Voltage Levels: The ST7789 typically works 3.3V, and the specific requirements may vary based on the module or display being used.
Widely Used in Projects: The ST7789 is often used in DIY electronics projects, especially those involving microcontrollers like Arduino, Raspberry Pi, STM32, and others.

The following image shows a ST7789 display module provided by Adafruit Industries:

Another version of the ST7789 display module is shown below, it is the one used in this tutorial. This one has no CS (chip select) pin that internally attached to GND. The resolution of this display is 240×240 pixel.

ST7789 color TFT display module pin description:

GND: Ground connection pin.
VCC: Power supply voltage pin.
SCL: Serial Clock pin. Connected to the SPI clock pin of the master device.
SDA: Serial Data Input pin. Connected to the SPI MOSI (Master Out Slave In) pin of the master device.
RES: Reset signal pin. Connected to a digital output pin on the master device. It is often optional, and if not used, it could be connected to master device reset pin or tied to a stable low level point.
DC (Data/Command): Data/Command control signal. Connected to a digital output pin on the master device. It determines whether the data on the bus is a command or actual pixel data.
BLK (Backlight): Backlight control pin. Connected to a digital output or PWM (Pulse Width Modulation) pin on the master device, it could be connected to VCC for maximum and permanent backlight on the display.

If the display has a CS pin:

CS: Chip Select pin. Connected to a digital pin on the master device. Used to enable or disable the communication with the ST7789 display.

Hardware Required:

Arduino UNO or similar board —> Board details.
ST7789 TFT display module.
4 x 3.3k ohm resistor (+1 if the display module has CS pin).
4 x 2.2k ohm resistor (+1 if the display module has CS pin).
Breadboard & jumper wires.

Interfacing Arduino with ST7789 TFT Display Circuit:
Project circuit schematic diagram is shown below.
The ST7789 display module shown in project circuit diagram has 7 pins: (from left to right): GND (ground), VCC, SCL (serial clock), SDA (serial data), RES (reset), DC (or D/C: data/command) and BLK (back light).

Arduino ST7789 TFT display circuit — Arduino UNO board with ST7789 display circuit

The ST7789 display used in this project works with voltage level of 3.3V only, this includes power supply and data/control signals. Note that all Arduino UNO board output pins are 5V, connecting a 5V output pin to the ST7789 TFT display may damage its controller chip.
For the power supply, the ST7789 display is supplied with 3.3V from the Arduino board. For data & control signals, I used resistor voltage divider for each line to scale down the Arduino 5V into 3V. Each voltage divider consists of 2.2k and 3.3k resistors.

Connection between the Arduino and the ST7789 display:
The ST7789 display is connected to the Arduino board as follows:
GND is connected to pin GND of the Arduino board.
VCC and BLK pins are connected to pin 3V3 of the Arduino board.
SCL pin is connected to pin 13 of the Arduino board (through voltage divider).
SDA pin is connected to pin 11 of the Arduino board (through voltage divider).
RST pin is connected to pin 8 of the Arduino board (through voltage divider).
DC pin is connected to pin 9 of the Arduino board (through voltage divider).

If the display module has a CS pin then it should be connected to pin 10 of the Arduino board through another resistive voltage divider.

Pins 13 and 11 are hardware SPI module pins of the ATmega328P microcontroller, respectively for SCK (serial clock) and MOSI (master-out slave-in).

Interfacing Arduino with ST7789 Color TFT Display Code:
Project Arduino code is just an example of graphics test provided by Adafruit Industries, with some minor modifications.
To be able to compile project Arduino code, two libraries are required from Adafruit Industries:

The first library is a driver for the ST7789 TFT display which can be installed from Arduino IDE library manager (Sketch —> Include Library —> Manage Libraries…, in the search box write “st7789” and install the one from Adafruit).
The second library is Adafruit graphics library which can be installed also from Arduino IDE library manager.
During installation of the Adafruit ST7789 library, Arduino IDE may ask for installing some other libraries form Adafruit Industries (dependencies).

Project code was tested with the following library versions:
Adafruit GFX Library: Version 1.11.9.
Adafruit ST7735 and ST7789 Library: Version 1.10.4.

Programming Hints:
The used libraries are included in the Arduino code as shown below:

#include <Adafruit_GFX.h>      // Include Adafruit Core graphics library
#include <Adafruit_ST7789.h>   // Include Adafruit Hardware-specific library for ST7789
#include <SPI.h>               // Include Arduino SPI library

1

2

3

#include <Adafruit_GFX.h> // Include Adafruit Core graphics library

#include <Adafruit_ST7789.h> // Include Adafruit Hardware-specific library for ST7789

#include <SPI.h> // Include Arduino SPI library

The connection between the Arduino UNO board and the ST7789 TFT display is as shown in the above circuit schematic, it is defined in the Arduino code as shown below:

// Define ST7789 display pin connection
#define TFT_CS     10   
#define TFT_RST     8   // Or set to -1 and connect to Arduino RESET pin
#define TFT_DC      9

1

2

3

4

// Define ST7789 display pin connection

#define TFT_CS 10

#define TFT_RST 8 // Or set to -1 and connect to Arduino RESET pin

#define TFT_DC 9

The initialization of the ST7789 TFT display library with the connections previously defined:

// Initialize the ST7789 display library with previously defined connections
Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);

1 2	// Initialize the ST7789 display library with previously defined connections Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);

The ST7789 display must be initialized before any print operation, if the initialization failed then the display will show only black screen. The initialization function of the display is the one below:

// Initialize the ST7789 TFT display
tft.init(240, 240, SPI_MODE3);   // Init ST7789 240x240

1 2	// Initialize the ST7789 TFT display tft.init(240, 240, SPI_MODE3); // Init ST7789 240x240

If the display failed to initialize properly then you have to try with another SPI Mode, replace SPI_MODE3 by one of the following:
SPI_MODE0
SPI_MODE1
SPI_MODE2

For more details about Arduino SPI communication, see the following page:
Arduino & Serial Peripheral Interface (SPI)

Rest of code is described through comments.

Full Arduino code:

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

 * Interfacing Arduino board with ST7789 TFT display (240x240 pixel).
 * This is a free software with NO WARRANTY.
 * https://simple-circuit.com/

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

#include <Adafruit_GFX.h>      // Include Adafruit Core graphics library
#include <Adafruit_ST7789.h>   // Include Adafruit Hardware-specific library for ST7789
#include <SPI.h>               // Include Arduino SPI library

// Define ST7789 display pin connection
#define TFT_CS     10   
#define TFT_RST     8   // Or set to -1 and connect to Arduino RESET pin
#define TFT_DC      9

// Initialize the ST7789 display library with previously defined connections
Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);

float p = 3.1415926;

void setup(void) {
  Serial.begin(9600);
  Serial.print(F("Hello! ST77xx TFT Test"));

  // Initialize the ST7789 TFT display
  tft.init(240, 240, SPI_MODE3);   // Init ST7789 240x240

  // if the screen is flipped, remove this command
  tft.setRotation(2);

  Serial.println(F("Initialized"));

  uint16_t time = millis();
  tft.fillScreen(ST77XX_BLACK);
  time = millis() - time;

  Serial.println(time, DEC);
  delay(500);

  // large block of text
  tft.fillScreen(ST77XX_BLACK);
  testdrawtext("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur adipiscing ante sed nibh tincidunt feugiat. Maecenas enim massa, fringilla sed malesuada et, malesuada sit amet turpis. Sed porttitor neque ut ante pretium vitae malesuada nunc bibendum. Nullam aliquet ultrices massa eu hendrerit. Ut sed nisi lorem. In vestibulum purus a tortor imperdiet posuere. ", ST77XX_WHITE);
  delay(1000);

  // tft print function!
  tftPrintTest();
  delay(4000);

  // a single pixel
  tft.drawPixel(tft.width()/2, tft.height()/2, ST77XX_GREEN);
  delay(500);

  // line draw test
  testlines(ST77XX_YELLOW);
  delay(500);

  // optimized lines
  testfastlines(ST77XX_RED, ST77XX_BLUE);
  delay(500);

  testdrawrects(ST77XX_GREEN);
  delay(500);

  testfillrects(ST77XX_YELLOW, ST77XX_MAGENTA);
  delay(500);

  tft.fillScreen(ST77XX_BLACK);
  testfillcircles(10, ST77XX_BLUE);
  testdrawcircles(10, ST77XX_WHITE);
  delay(500);

  testroundrects();
  delay(500);

  testtriangles();
  delay(500);

  mediabuttons();
  delay(500);

  Serial.println("done");
  delay(1000);
}

void loop() {
  tft.invertDisplay(true);
  delay(500);
  tft.invertDisplay(false);
  delay(500);
}

void testlines(uint16_t color) {
  tft.fillScreen(ST77XX_BLACK);
  for (int16_t x=0; x < tft.width(); x+=6) {
    tft.drawLine(0, 0, x, tft.height()-1, color);
    delay(0);
  }
  for (int16_t y=0; y < tft.height(); y+=6) {
    tft.drawLine(0, 0, tft.width()-1, y, color);
    delay(0);
  }

  tft.fillScreen(ST77XX_BLACK);
  for (int16_t x=0; x < tft.width(); x+=6) {
    tft.drawLine(tft.width()-1, 0, x, tft.height()-1, color);
    delay(0);
  }
  for (int16_t y=0; y < tft.height(); y+=6) {
    tft.drawLine(tft.width()-1, 0, 0, y, color);
    delay(0);
  }

  tft.fillScreen(ST77XX_BLACK);
  for (int16_t x=0; x < tft.width(); x+=6) {
    tft.drawLine(0, tft.height()-1, x, 0, color);
    delay(0);
  }
  for (int16_t y=0; y < tft.height(); y+=6) {
    tft.drawLine(0, tft.height()-1, tft.width()-1, y, color);
    delay(0);
  }

  tft.fillScreen(ST77XX_BLACK);
  for (int16_t x=0; x < tft.width(); x+=6) {
    tft.drawLine(tft.width()-1, tft.height()-1, x, 0, color);
    delay(0);
  }
  for (int16_t y=0; y < tft.height(); y+=6) {
    tft.drawLine(tft.width()-1, tft.height()-1, 0, y, color);
    delay(0);
  }
}

void testdrawtext(char *text, uint16_t color) {
  tft.setCursor(0, 0);
  tft.setTextColor(color);
  tft.setTextWrap(true);
  tft.print(text);
}

void testfastlines(uint16_t color1, uint16_t color2) {
  tft.fillScreen(ST77XX_BLACK);
  for (int16_t y=0; y < tft.height(); y+=5) {
    tft.drawFastHLine(0, y, tft.width(), color1);
  }
  for (int16_t x=0; x < tft.width(); x+=5) {
    tft.drawFastVLine(x, 0, tft.height(), color2);
  }
}

void testdrawrects(uint16_t color) {
  tft.fillScreen(ST77XX_BLACK);
  for (int16_t x=0; x < tft.width(); x+=6) {
    tft.drawRect(tft.width()/2 -x/2, tft.height()/2 -x/2 , x, x, color);
  }
}

void testfillrects(uint16_t color1, uint16_t color2) {
  tft.fillScreen(ST77XX_BLACK);
  for (int16_t x=tft.width()-1; x > 6; x-=6) {
    tft.fillRect(tft.width()/2 -x/2, tft.height()/2 -x/2 , x, x, color1);
    tft.drawRect(tft.width()/2 -x/2, tft.height()/2 -x/2 , x, x, color2);
  }
}

void testfillcircles(uint8_t radius, uint16_t color) {
  for (int16_t x=radius; x < tft.width(); x+=radius*2) {
    for (int16_t y=radius; y < tft.height(); y+=radius*2) {
      tft.fillCircle(x, y, radius, color);
    }
  }
}

void testdrawcircles(uint8_t radius, uint16_t color) {
  for (int16_t x=0; x < tft.width()+radius; x+=radius*2) {
    for (int16_t y=0; y < tft.height()+radius; y+=radius*2) {
      tft.drawCircle(x, y, radius, color);
    }
  }
}

void testtriangles() {
  tft.fillScreen(ST77XX_BLACK);
  uint16_t color = 0xF800;
  int t;
  int w = tft.width()/2;
  int x = tft.height()-1;
  int y = 0;
  int z = tft.width();
  for(t = 0 ; t <= 15; t++) {
    tft.drawTriangle(w, y, y, x, z, x, color);
    x-=4;
    y+=4;
    z-=4;
    color+=100;
  }
}

void testroundrects() {
  tft.fillScreen(ST77XX_BLACK);
  uint16_t color = 100;
  int i;
  int t;
  for(t = 0 ; t <= 4; t+=1) {
    int x = 0;
    int y = 0;
    int w = tft.width()-2;
    int h = tft.height()-2;
    for(i = 0 ; i <= 16; i+=1) {
      tft.drawRoundRect(x, y, w, h, 5, color);
      x+=2;
      y+=3;
      w-=4;
      h-=6;
      color+=1100;
    }
    color+=100;
  }
}

void tftPrintTest() {
  tft.setTextWrap(false);
  tft.fillScreen(ST77XX_BLACK);
  tft.setCursor(0, 30);
  tft.setTextColor(ST77XX_RED);
  tft.setTextSize(1);
  tft.println("Hello World!");
  tft.setTextColor(ST77XX_YELLOW);
  tft.setTextSize(2);
  tft.println("Hello World!");
  tft.setTextColor(ST77XX_GREEN);
  tft.setTextSize(3);
  tft.println("Hello World!");
  tft.setTextColor(ST77XX_BLUE);
  tft.setTextSize(4);
  tft.print(1234.567);
  delay(1500);
  tft.setCursor(0, 0);
  tft.fillScreen(ST77XX_BLACK);
  tft.setTextColor(ST77XX_WHITE);
  tft.setTextSize(0);
  tft.println("Hello World!");
  tft.setTextSize(1);
  tft.setTextColor(ST77XX_GREEN);
  tft.print(p, 6);
  tft.println(" Want pi?");
  tft.println(" ");
  tft.print(8675309, HEX); // print 8,675,309 out in HEX!
  tft.println(" Print HEX!");
  tft.println(" ");
  tft.setTextColor(ST77XX_WHITE);
  tft.println("Sketch has been");
  tft.println("running for: ");
  tft.setTextColor(ST77XX_MAGENTA);
  tft.print(millis() / 1000);
  tft.setTextColor(ST77XX_WHITE);
  tft.print(" seconds.");
}

void mediabuttons() {
  // play
  tft.fillScreen(ST77XX_BLACK);
  tft.fillRoundRect(25, 10, 78, 60, 8, ST77XX_WHITE);
  tft.fillTriangle(42, 20, 42, 60, 90, 40, ST77XX_RED);
  delay(500);
  // pause
  tft.fillRoundRect(25, 90, 78, 60, 8, ST77XX_WHITE);
  tft.fillRoundRect(39, 98, 20, 45, 5, ST77XX_GREEN);
  tft.fillRoundRect(69, 98, 20, 45, 5, ST77XX_GREEN);
  delay(500);
  // play color
  tft.fillTriangle(42, 20, 42, 60, 90, 40, ST77XX_BLUE);
  delay(50);
  // pause color
  tft.fillRoundRect(39, 98, 20, 45, 5, ST77XX_RED);
  tft.fillRoundRect(69, 98, 20, 45, 5, ST77XX_RED);
  // play color
  tft.fillTriangle(42, 20, 42, 60, 90, 40, ST77XX_GREEN);
}

/**************************************************************************
  This is a library for several Adafruit displays based on ST77* drivers.

  Works with the Adafruit 1.8" TFT Breakout w/SD card
    ----> http://www.adafruit.com/products/358
  The 1.8" TFT shield
    ----> https://www.adafruit.com/product/802
  The 1.44" TFT breakout
    ----> https://www.adafruit.com/product/2088
  The 1.14" TFT breakout
  ----> https://www.adafruit.com/product/4383
  The 1.3" TFT breakout
  ----> https://www.adafruit.com/product/4313
  The 1.54" TFT breakout
    ----> https://www.adafruit.com/product/3787
  The 1.69" TFT breakout
    ----> https://www.adafruit.com/product/5206
  The 2.0" TFT breakout
    ----> https://www.adafruit.com/product/4311
  as well as Adafruit raw 1.8" TFT display
    ----> http://www.adafruit.com/products/618

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

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

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

* Interfacing Arduino board with ST7789 TFT display (240x240 pixel).

* This is a free software with NO WARRANTY.

* https://simple-circuit.com/

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

#include <Adafruit_GFX.h> // Include Adafruit Core graphics library

#include <Adafruit_ST7789.h> // Include Adafruit Hardware-specific library for ST7789

#include <SPI.h> // Include Arduino SPI library

// Define ST7789 display pin connection

#define TFT_CS 10

#define TFT_RST 8 // Or set to -1 and connect to Arduino RESET pin

#define TFT_DC 9

// Initialize the ST7789 display library with previously defined connections

Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);

float p = 3.1415926;

void setup(void) {

Serial.begin(9600);

Serial.print(F("Hello! ST77xx TFT Test"));

// Initialize the ST7789 TFT display

tft.init(240, 240, SPI_MODE3); // Init ST7789 240x240

// if the screen is flipped, remove this command

tft.setRotation(2);

Serial.println(F("Initialized"));

uint16_t time = millis();

tft.fillScreen(ST77XX_BLACK);

time = millis() - time;

Serial.println(time, DEC);

delay(500);

// large block of text

tft.fillScreen(ST77XX_BLACK);

testdrawtext("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur adipiscing ante sed nibh tincidunt feugiat. Maecenas enim massa, fringilla sed malesuada et, malesuada sit amet turpis. Sed porttitor neque ut ante pretium vitae malesuada nunc bibendum. Nullam aliquet ultrices massa eu hendrerit. Ut sed nisi lorem. In vestibulum purus a tortor imperdiet posuere. ", ST77XX_WHITE);

delay(1000);

// tft print function!

tftPrintTest();

delay(4000);

// a single pixel

tft.drawPixel(tft.width()/2, tft.height()/2, ST77XX_GREEN);

delay(500);

// line draw test

testlines(ST77XX_YELLOW);

delay(500);

// optimized lines

testfastlines(ST77XX_RED, ST77XX_BLUE);

delay(500);

testdrawrects(ST77XX_GREEN);

delay(500);

testfillrects(ST77XX_YELLOW, ST77XX_MAGENTA);

delay(500);

tft.fillScreen(ST77XX_BLACK);

testfillcircles(10, ST77XX_BLUE);

testdrawcircles(10, ST77XX_WHITE);

delay(500);

testroundrects();

delay(500);

testtriangles();

delay(500);

mediabuttons();

delay(500);

Serial.println("done");

delay(1000);

}

void loop() {

tft.invertDisplay(true);

delay(500);

tft.invertDisplay(false);

delay(500);

}

void testlines(uint16_t color) {

tft.fillScreen(ST77XX_BLACK);

for (int16_t x=0; x < tft.width(); x+=6) {

tft.drawLine(0, 0, x, tft.height()-1, color);

delay(0);

}

for (int16_t y=0; y < tft.height(); y+=6) {

tft.drawLine(0, 0, tft.width()-1, y, color);

delay(0);

}

tft.fillScreen(ST77XX_BLACK);

for (int16_t x=0; x < tft.width(); x+=6) {

tft.drawLine(tft.width()-1, 0, x, tft.height()-1, color);

delay(0);

}

for (int16_t y=0; y < tft.height(); y+=6) {

tft.drawLine(tft.width()-1, 0, 0, y, color);

delay(0);

}

tft.fillScreen(ST77XX_BLACK);

for (int16_t x=0; x < tft.width(); x+=6) {

tft.drawLine(0, tft.height()-1, x, 0, color);

delay(0);

}

for (int16_t y=0; y < tft.height(); y+=6) {

tft.drawLine(0, tft.height()-1, tft.width()-1, y, color);

delay(0);

}

tft.fillScreen(ST77XX_BLACK);

for (int16_t x=0; x < tft.width(); x+=6) {

tft.drawLine(tft.width()-1, tft.height()-1, x, 0, color);

delay(0);

}

for (int16_t y=0; y < tft.height(); y+=6) {

tft.drawLine(tft.width()-1, tft.height()-1, 0, y, color);

delay(0);

}

}

void testdrawtext(char *text, uint16_t color) {

tft.setCursor(0, 0);

tft.setTextColor(color);

tft.setTextWrap(true);

tft.print(text);

}

void testfastlines(uint16_t color1, uint16_t color2) {

tft.fillScreen(ST77XX_BLACK);

for (int16_t y=0; y < tft.height(); y+=5) {

tft.drawFastHLine(0, y, tft.width(), color1);

}

for (int16_t x=0; x < tft.width(); x+=5) {

tft.drawFastVLine(x, 0, tft.height(), color2);

}

}

void testdrawrects(uint16_t color) {

tft.fillScreen(ST77XX_BLACK);

for (int16_t x=0; x < tft.width(); x+=6) {

tft.drawRect(tft.width()/2 -x/2, tft.height()/2 -x/2 , x, x, color);

}

}

void testfillrects(uint16_t color1, uint16_t color2) {

tft.fillScreen(ST77XX_BLACK);

for (int16_t x=tft.width()-1; x > 6; x-=6) {

tft.fillRect(tft.width()/2 -x/2, tft.height()/2 -x/2 , x, x, color1);

tft.drawRect(tft.width()/2 -x/2, tft.height()/2 -x/2 , x, x, color2);

}

}

void testfillcircles(uint8_t radius, uint16_t color) {

for (int16_t x=radius; x < tft.width(); x+=radius*2) {

for (int16_t y=radius; y < tft.height(); y+=radius*2) {

tft.fillCircle(x, y, radius, color);

}

}

}

void testdrawcircles(uint8_t radius, uint16_t color) {

for (int16_t x=0; x < tft.width()+radius; x+=radius*2) {

for (int16_t y=0; y < tft.height()+radius; y+=radius*2) {

tft.drawCircle(x, y, radius, color);

}

}

}

void testtriangles() {

tft.fillScreen(ST77XX_BLACK);

uint16_t color = 0xF800;

int t;

int w = tft.width()/2;

int x = tft.height()-1;

int y = 0;

int z = tft.width();

for(t = 0 ; t <= 15; t++) {

tft.drawTriangle(w, y, y, x, z, x, color);

x-=4;

y+=4;

z-=4;

color+=100;

}

}

void testroundrects() {

tft.fillScreen(ST77XX_BLACK);

uint16_t color = 100;

int i;

int t;

for(t = 0 ; t <= 4; t+=1) {

int x = 0;

int y = 0;

int w = tft.width()-2;

int h = tft.height()-2;

for(i = 0 ; i <= 16; i+=1) {

tft.drawRoundRect(x, y, w, h, 5, color);

x+=2;

y+=3;

w-=4;

h-=6;

color+=1100;

}

color+=100;

}

}

void tftPrintTest() {

tft.setTextWrap(false);

tft.fillScreen(ST77XX_BLACK);

tft.setCursor(0, 30);

tft.setTextColor(ST77XX_RED);

tft.setTextSize(1);

tft.println("Hello World!");

tft.setTextColor(ST77XX_YELLOW);

tft.setTextSize(2);

tft.println("Hello World!");

tft.setTextColor(ST77XX_GREEN);

tft.setTextSize(3);

tft.println("Hello World!");

tft.setTextColor(ST77XX_BLUE);

tft.setTextSize(4);

tft.print(1234.567);

delay(1500);

tft.setCursor(0, 0);

tft.fillScreen(ST77XX_BLACK);

tft.setTextColor(ST77XX_WHITE);

tft.setTextSize(0);

tft.println("Hello World!");

tft.setTextSize(1);

tft.setTextColor(ST77XX_GREEN);

tft.print(p, 6);

tft.println(" Want pi?");

tft.println(" ");

tft.print(8675309, HEX); // print 8,675,309 out in HEX!

tft.println(" Print HEX!");

tft.println(" ");

tft.setTextColor(ST77XX_WHITE);

tft.println("Sketch has been");

tft.println("running for: ");

tft.setTextColor(ST77XX_MAGENTA);

tft.print(millis() / 1000);

tft.setTextColor(ST77XX_WHITE);

tft.print(" seconds.");

}

void mediabuttons() {

// play

tft.fillScreen(ST77XX_BLACK);

tft.fillRoundRect(25, 10, 78, 60, 8, ST77XX_WHITE);

tft.fillTriangle(42, 20, 42, 60, 90, 40, ST77XX_RED);

delay(500);

// pause

tft.fillRoundRect(25, 90, 78, 60, 8, ST77XX_WHITE);

tft.fillRoundRect(39, 98, 20, 45, 5, ST77XX_GREEN);

tft.fillRoundRect(69, 98, 20, 45, 5, ST77XX_GREEN);

delay(500);

// play color

tft.fillTriangle(42, 20, 42, 60, 90, 40, ST77XX_BLUE);

delay(50);

// pause color

tft.fillRoundRect(39, 98, 20, 45, 5, ST77XX_RED);

tft.fillRoundRect(69, 98, 20, 45, 5, ST77XX_RED);

// play color

tft.fillTriangle(42, 20, 42, 60, 90, 40, ST77XX_GREEN);

}

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

This is a library for several Adafruit displays based on ST77* drivers.

Works with the Adafruit 1.8" TFT Breakout w/SD card

----> http://www.adafruit.com/products/358

The 1.8" TFT shield

----> https://www.adafruit.com/product/802

The 1.44" TFT breakout

----> https://www.adafruit.com/product/2088

The 1.14" TFT breakout

----> https://www.adafruit.com/product/4383

The 1.3" TFT breakout

----> https://www.adafruit.com/product/4313

The 1.54" TFT breakout

----> https://www.adafruit.com/product/3787

The 1.69" TFT breakout

----> https://www.adafruit.com/product/5206

The 2.0" TFT breakout

----> https://www.adafruit.com/product/4311

as well as Adafruit raw 1.8" TFT display

----> http://www.adafruit.com/products/618

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

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

Interfacing Arduino with ST7789 Color TFT Display Video:
The video below shows my DIY test hardware circuit of a Arduino UNO with ST7789 TFT display:

Discover more from Simple Circuit

Subscribe to get the latest posts sent to your email.

1 thought on “Arduino Interface with ST7789 Color TFT Display”

John
October 20, 2024 at 1:04 am
The omitted CS pin was presumably a design decision to keep the size compact. There is a tricky solderable solution that loses the BLK pin function. Alternatively it is possible to make an adapter that gives the screen a CS function – and can also do level shifting for a 5v Arduino down to a required 3v3 device..
A 74HC245 octal non-inverting transceiver with VCC 3v3 has very good input clamp capability. An input series resistor of 1k (or 4k7) limits the current from an Arduino 5v output to a few hundred microamps.
The transceiver DIR is locked to one direction – passing through the SCL, SDA, DC, RST signals. The tristate Output Enable is used as the spoofed active LOW SPI CS for the device. The CS signal with compatible timing delay could also be passed through if only level shifting was required for use for more generic screens..NB. All unused 74HC inputs must be grounded.
Output 10k0 pull-ups keep the screen’s inputs stable when CS is not selected. The SPI_MODE2 is needed to ensure the Arduino idles SPI SCL at HIGH. It appears that all other connected SPI devices may need to have the same mode – even though it is presumed to be configurable for each device.
The screen seems to do its own Reset at power-up – unless it was a quirk of my breadboard. It is assumed that driver RST is issued with idle SCL. It has proved possible to connect a Schottky diode between RST (cathode) and CS inputs. Thus the RST LOW drives CS LOW to allow the RST signal through the buffer. The screen is not otherwise affected as SCL is HIGH.
The 3v3 is supplied locally by a simple regulator from the 5v line from the Arduino.
Blanking in the current implementation is achieved by a 5v SPST NO reed relay locally shorting BLK to ground. That keeps the Backlight path resistance much lower than it would be over my nearly 2m of 8 way cable.
The 74HC245 was chosen from a set of possible 74HC tristate buffers (eg 241, 243) as it offered a compact symmetrical layout on 2.54mm stripboard.
Reply

Leave a Comment Cancel Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.