Interfacing PIC16F877A with ST7735 1.8" SPI TFT Color Display
Interfacing PIC18F4550 with 1.8" TFT display
For this project we need a CCS C compiler library for the ST7735 TFT display which can be found in the link below with some descriptions:
ST7735 SPI TFT Display Driver for CCS PIC C compiler
Or you can just download it directly from the following link:
ST7735 SPI TFT Display Driver
Put the downloaded C file in your project folder.
Required Components:
- PIC16F877A Microcontroller
- ST7735R (or ST7735S) 1.8" SPI TFT Display
- 8MHz Crystal oscillator
- 2 x 22pF Capacitors
- 10K Resistor
- 5 x 1K Resistors (If the system is 3.3V there is no need for these resistors)
- Power Supply Source (+5V or +3.3V)
- Breadboard
- Jumper Wires
The microcontroller runs with 8MHz crystal oscillator, if you want to get better result (fast) use a crystal with higher frequency up to 20MHz.
ST7735 1.8" TFT display with PIC16F877A example CCS C code:
PIC16F877A hardware SPI module is used to send data to the TFT display. SPI module uses the following pins:
SDI (RC4): data input pin (not used in this project)
SCK (RC3): clock line
SDO (RC5): data output
// TFT module connections
#define TFT_CS PIN_D1
#define TFT_DC PIN_D0
#define TFT_SPI_HARDWARE
// End TFT module connections
My TFT display is ST7735R Black Tap (ST7735S) and for initializing this type of TFT display I used the following line:
TFT_BlackTab_Initialize();
If you have a TFT display with green or red tabs or a TFT with ST7735B controller read the driver topic above.
Note that green, red and black tabs have the same controller ST7735R.
fillScreen(ST7735_BLACK); // Fill all the screen with black
The following line means that the TFT willl display a text called txt starting from coordinates (0, 30) with red color, black background and size 1.
drawtext(0, 30, txt, ST7735_RED, ST7735_BLACK, 1);
The following line will display a white straight horizontal line starting from coordinates (0, 53).
drawFastHLine(0, 53, _width, ST7735_WHITE);
This code is tested with CCS PIC C compiler PCWHD versions 4 and 5.
// PIC16F877A and ST7735 1.8" SPI color TFT display example CCS C code // ST7735 TFT display driver for CCS PIC C compiler is required // http: //ccspicc.blogspot.com/ // electronnote@gmail.com // TFT module connections #define TFT_CS PIN_D1 #define TFT_DC PIN_D0 #define TFT_SPI_HARDWARE // End TFT module connections #include <16F877A.h> #fuses HS,NOWDT,NOPROTECT,NOLVP #use delay(clock = 8000000) #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); } }ST7735 1.8" TFT display with PIC16F877A example video:
Simple hardware circuit of this example.