This is an example for connecting the ST7735 1.8″ color TFT display with PIC16F887 microcontroller. The compiler used in this project is CCS PIC C compiler.
The ST7735 needs a driver which can be found in the topic below:
ST7735 SPI TFT Display Driver for CCS PIC C compiler
After downloading the driver file just put it on the project folder.
The ST7735 uses SPI communication protocol and the PIC16F887 has one SPI module.
Generally the SPI protocol uses 3 lines: SCK (serial clock), SDI (serial data in) and SDO (serial data out) but for interfacing the ST7735 TFT we use only 2 lines: SCK and SDO.
The PIC16F887 has one SPI module with SCK mapped to RC3 pin (#18) and SDO mapped to RC5 (#24).
Components Required:
- PIC16F887 microcontroller
- ST7735 1.8″ TFT display
- 20MHz crystal oscillator
- 2 x 22pF ceramic capacitor
- 5 x 1k ohm resistors
- Protoboard
- 5V Power supply source
- Jumper wires
Interfacing PIC16F887 with ST7735 TFT display circuit:
Example circuit diagram is shown below.
TFT pin-out are shown in the circuit diagram above.
In this project I used 20MHz crystal oscillator which is the PIC16F887 maximum speed for highest SPI data transfer rate (5Mbit/s). Lower crystal frequencies can be used or even the internal oscillator of the microcontroller.
5 x 1K ohm resistors are needed because basically the ST7735 works with 3.3V and the PIC16F887 works with 5V , it may be damaged if it connected directly to the microcontroller. The TFT is supplied with +5V because its board contains AMS1117 3.3V voltage regulator.
Interfacing PIC16F887 with ST7735 TFT display CCS C code:
The code has been tested with CCS PIC C compiler version 5.051.
ST7735 TFT driver is needed to compile the code.
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 | /* PIC16F887 with ST7735 TFT display example C code ST7735 TFT display driver for CCS PIC C compiler is required Coordinates are (x, y) starting from upper left corner (0, 0) */ // TFT module connections #define TFT_CS PIN_D0 #define TFT_DC PIN_D1 #define TFT_SPI_HARDWARE // End TFT module connections #include <16F887.h> #fuses NOMCLR NOBROWNOUT NOLVP HS #use delay(clock = 20MHz) #include <ST7735_TFT.c> int8 k = 0; char *txt = "1.8 Inch ST7735 TFT display test example"; void testlines(unsigned int16 color) { unsigned int8 x, y; fillScreen(ST7735_BLACK); for (x=0; x < _width; x+=6) { drawLine(0, 0, x, _height-1, color); } for (y=0; y < _height; y+=6) { drawLine(0, 0, _width-1, y, color); } fillScreen(ST7735_BLACK); for (x=0; x < _width; x+=6) { drawLine(_width-1, 0, x, _height-1, color); } for (y=0; y < _height; y+=6) { drawLine(_width-1, 0, 0, y, color); } fillScreen(ST7735_BLACK); for (x=0; x < _width; x+=6) { drawLine(0, _height-1, x, 0, color); } for (y=0; y < _height; y+=6) { drawLine(0, _height-1, _width-1, y, color); } fillScreen(ST7735_BLACK); for (x=0; x < _width; x+=6) { drawLine(_width-1, _height-1, x, 0, color); } for (y=0; y < _height; y+=6) { drawLine(_width-1, _height-1, 0, y, color); } } void testfastlines(unsigned int16 color1, unsigned int16 color2) { int16 x, y; fillScreen(ST7735_BLACK); for (y = 0; y < _height; y += 5) { drawFastHLine(0, y, _width, color1); } for (x = 0; x < _width; x += 5) { drawFastVLine(x, 0, _height, color2); } } void testdrawrects(unsigned int16 color) { int16 x; fillScreen(ST7735_BLACK); for (x = 0; x < _width; x+=6) { drawRect(_width/2 -x/2, _height/2 -x/2 , x, x, color); } } void testfillrects(unsigned int16 color1, unsigned int16 color2) { int16 x; fillScreen(ST7735_BLACK); for (x = _width - 1; x > 6; x -= 6) { fillRect(_width/2 -x/2, _height/2 -x/2 , x, x, color1); drawRect(_width/2 -x/2, _height/2 -x/2 , x, x, color2); } } void testfillcircles(unsigned int8 radius, unsigned int16 color) { int16 x, y; for (x = radius; x < _width; x += radius * 2) { for (y = radius; y < _height; y += radius * 2) { fillCircle(x, y, radius, color); } } } void testdrawcircles(unsigned int8 radius, unsigned int16 color) { int16 x, y; for (x = 0; x < _width + radius; x += radius * 2) { for (y = 0; y < _height + radius; y += radius * 2) { drawCircle(x, y, radius, color); } } } void testroundrects() { int8 i, t; unsigned int16 color = 100; fillScreen(ST7735_BLACK); for(t = 0 ; t <= 4; t += 1) { unsigned int8 x = 0, y = 0, w = _width - 2, h = _height - 2; for(i = 0 ; i <= 16; i++) { drawRoundRect(x, y, w, h, 5, color); x += 2; y += 3; w -= 4; h -= 6; color += 1100; } color += 100; } } void testtriangles() { unsigned int8 t, w, x, y, z; unsigned int16 color = 0xF800; fillScreen(ST7735_BLACK); w = _width/2, x = _height - 1, y = 0, z = _width; for(t = 0 ; t <= 15; t++) { drawTriangle(w, y, y, x, z, x, color); x -= 4; y += 4; z -= 4; color += 100; } } void mediabuttons() { // play fillScreen(ST7735_BLACK); fillRoundRect(25, 10, 78, 60, 8, ST7735_WHITE); fillTriangle(42, 20, 42, 60, 90, 40, ST7735_RED); delay_ms(500); // pause fillRoundRect(25, 90, 78, 60, 8, ST7735_WHITE); fillRoundRect(39, 98, 20, 45, 5, ST7735_GREEN); fillRoundRect(69, 98, 20, 45, 5, ST7735_GREEN); delay_ms(500); // play color fillTriangle(42, 20, 42, 60, 90, 40, ST7735_BLUE); delay_ms(50); // pause color fillRoundRect(39, 98, 20, 45, 5, ST7735_RED); fillRoundRect(69, 98, 20, 45, 5, ST7735_RED); // play color fillTriangle(42, 20, 42, 60, 90, 40, ST7735_GREEN); } void main(){ TFT_BlackTab_Initialize(); fillScreen(ST7735_BLACK); drawtext(0, 5, txt, ST7735_WHITE, ST7735_BLACK, 1); setTextWrap(false); strcpy (txt, "Hello World!"); drawtext(0, 30, txt, ST7735_RED, ST7735_BLACK, 1); drawtext(0, 47, txt, ST7735_YELLOW, ST7735_BLACK, 2); drawtext(0, 80, txt, ST7735_MAGENTA, ST7735_BLACK, 3); drawtext(0, 120, txt, ST7735_CYAN, ST7735_BLACK, 4); delay_ms(5000); fillScreen(ST7735_BLACK); drawFastHLine(0, 53, _width, ST7735_WHITE); drawFastHLine(0, 106, _width, ST7735_WHITE); while(k++ < 20){ sprintf(txt,"%02u",k); drawtext(59, 25, txt, ST7735_GREEN, ST7735_BLACK, 1); drawtext(54, 75, txt, ST7735_BLUE, ST7735_BLACK, 2); drawtext(49, 125, txt, ST7735_RED, ST7735_BLACK, 3); delay_ms(500); } testlines(ST7735_YELLOW); delay_ms(1000); testfastlines(ST7735_RED, ST7735_BLUE); delay_ms(1000); testdrawrects(ST7735_GREEN); delay_ms(1000); testfillrects(ST7735_YELLOW, ST7735_MAGENTA); delay_ms(1000); fillScreen(ST7735_BLACK); testfillcircles(10, ST7735_BLUE); testdrawcircles(10, ST7735_WHITE); delay_ms(1000); testroundrects(); delay_ms(1000); testtriangles(); delay_ms(1000); mediabuttons(); delay_ms(1000); while(TRUE){ invertDisplay(true); delay_ms(500); invertDisplay(false); delay_ms(500); } } |
Finally the following video shows the ST7735 and PIC16F887 in a protoboard circuit:
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