1 /* (CC-BY-NC-SA) ROBIN KRENS - ROBIN @ ROBINKRENS.NL
4 * 2019/9/14 - ROBIN KRENS
19 #include <sys/robsys.h>
21 #include <lib/regfunc.h>
22 #include <lib/string.h>
23 #include <lib/tinyprintf.h>
25 #include <drivers/st7735s.h>
33 /* Peripherial init */
34 rsetbit(RCC_APB1ENR, 14); // enable SPI2
35 rsetbit(RCC_APB2ENR, 3); // enable GPIOB
36 rsetbit(RCC_APB2ENR, 4); // enable GPIOC
38 /* The PINS used are PB12, PB13, PB15 and PC6 respectively
39 * NSS (or CS): alternative function pusp-pull
40 * NSS Output is (always high) enabled with this setting
41 * SCK Master: alternate function push-pull
42 * MOSI (or DI): alternate function push-pull
43 * D/CX (or A0): Command or data write line PC6 */
44 rwrite(GPIOB_CRH, 0xA4AA4444);
45 rwrite(GPIOC_CRL, 0x42444444);
47 /* Chip select: software enabled
48 * In case for a hardware setup, connect NSS (CS) to
53 rsetbit(SPI2_CR1, 15); // one-wire mode
54 rsetbit(SPI2_CR1, 14); // start with transfer
55 rsetbit(SPI2_CR1, 4); // FPLCK div 8
56 rsetbit(SPI2_CR1, 2); // master selection
57 rsetbit(SPI2_CR1, 6); // enable SPI
60 tft_command(TFT_SWRESET, 0);
65 /* Frame rate control */
66 tft_command(TFT_FRMCTR1, 3, 0x01, 0x2C, 0x2D);
67 tft_command(TFT_FRMCTR2, 3, 0x01, 0x2C, 0x2D);
68 tft_command(TFT_FRMCTR3, 6, 0x01, 0x2C, 0x2D, 0x01, 0x2C, 0x2D);
71 tft_command(TFT_PWCTR1, 3, 0xA2, 0x02, 0x84);
72 tft_command(TFT_PWCTR2, 1, 0xC5);
73 tft_command(TFT_PWCTR3, 2, 0x0A, 0x00);
74 tft_command(TFT_PWCTR4, 2, 0x8A, 0x2A);
75 tft_command(TFT_PWCTR5, 2, 0x8A, 0xEE);
76 tft_command(TFT_VMCTR1, 1, 0x0E);
78 tft_command(TFT_INVOFF, 0);
79 tft_command(TFT_COLMOD, 1, 0x05); // 0x05
80 tft_command(TFT_MADCTL, 1, 0xC0); // TODO: check
82 tft_command(TFT_CASET, 4, 0x00, 0x00, 0x00, 0x7F);
83 tft_command(TFT_RASET, 4, 0x00, 0x00, 0x00, 0x9F);
86 tft_command(TFT_GMCTRP1, 16, 0x02, 0x1C, 0x07, 0x12,
87 0x37, 0x32, 0x29, 0x2D,
88 0x29, 0x25, 0x2B, 0x39,
89 0x00, 0x01, 0x03, 0x10);
90 tft_command(TFT_GMCTRN1, 16, 0x03, 0x1D, 0x07, 0x06,
91 0x2E, 0x2C, 0x29, 0x2D,
92 0x2E, 0x2E, 0x37, 0x3F,
93 0x00, 0x00, 0x02, 0x10);
95 /* Before turning on the display, fill the display
96 * so no random display data is shown */
97 tft_fill(0,0,SCRWIDTH-1,SCRHEIGHT-1,0x001F);
98 tft_setpixel(50,50,0xFFFF);
101 tft_command(TFT_NORON, 0);
103 tft_command(TFT_DISPON, 0);
109 tft_command(TFT_CASET, 4, 0x00, 0x08, 0x00, 0x09);
110 tft_command(TFT_RASET, 4, 0x00, 0x08, 0x00, 0x09);
111 tft_command(TFT_RAMRD, 0);
113 //tft_command(0x0C, 0);
114 //tft_command(0x0A, 0);
116 rclrbit(SPI2_CR1, 14); // receive
118 while(!rchkbit(SPI2_SR, 0));
119 uint8_t chip_id = *SPI2_DR;
120 printf("COLMOD: %#x\n", chip_id); */
122 rclrbit(SPI2_CR1, 8); // deselect
125 /* Helper function */
126 static int txbuf_empty () {
128 while(!rchkbit(SPI2_SR, 1)) {
131 printf("Error: transmit timeout!\n");
140 /* Function to fill an area starting at (beginx, beginy)
141 * and end ending at (endx, endy */
142 int tft_fill(uint8_t beginx, uint8_t beginy, uint8_t endx,
143 uint8_t endy, uint16_t color) {
145 /* The CASET and RASET commands set the begin X/Y
146 * and end X/Y of the fill area. Both are split over
147 * two paramters/bytes. Most screen are small, so you will
148 * only need to consider the first 8 MSBs. Parameter 1 and
151 * In theory, TFT screens of 65,535 by 65,535 could be
153 tft_command(TFT_CASET, 4, 0x00, beginx, 0x00, endx);
154 tft_command(TFT_RASET, 4, 0x00, beginy, 0x00, endy);
156 /* After setting the fill area, we can send the color
157 * data. The chip autoincrements the address so we can
158 * keep writing continiously for the fill area. Note
159 * that each pixel requires two bytes to be send (16
161 uint32_t totalwrites = (endx - beginx) * (endy - beginy) * 2;
162 //printf("tw: %d, x: %d, y: %d\n", totalwrites, beginx, beginy);
163 tft_command(TFT_RAMWR, 0);
164 rsetbit(GPIOC_ODR, 6); // data = 1
165 for (int i = 0; i < totalwrites; i++) {
166 rwrite(SPI2_DR, (uint8_t) (color >> 8));
169 rwrite(SPI2_DR, (uint8_t) (color & 0xFF));
176 /* Function to individually set a pixel
177 * Refer to tft_fill, similar calls */
178 int tft_setpixel(uint8_t x, uint8_t y, uint16_t color) {
180 tft_command(TFT_CASET, 4, 0x00, x, 0x00, x+1);
181 tft_command(TFT_RASET, 4, 0x00, y, 0x00, y+1);
182 tft_command(TFT_RAMWR, 2, (uint8_t) (color >> 8), (uint8_t) (color & 0xFF));
186 /* Low-level function to print a character to the display
187 * Should not be used directly, since it does not set
189 int tft_putc(uint16_t fg, uint16_t bg, char c) {
195 /* Invokes commands with a variable list of paramaters. Sending paramters
196 * requires the D/CX line to be high */
197 int tft_command(uint8_t cmd, int argsc, ...) {
201 rclrbit(GPIOC_ODR, 6); // D/CX line low
202 rwrite(SPI2_DR, cmd);
209 rsetbit(GPIOC_ODR, 6); // D/CX line high
210 for (int i = 0; i < argsc; i++) {
211 uint8_t p = (uint8_t) va_arg(ap, unsigned int);