图片
下一步把ascii 8*8点阵输入程序，屏幕就可以显示ascii字符了，最终把此显示程序写成函数，输入参数为要显示字符的数组，这样就是st7735的显示驱动程序了。当然还要加入显示自动换行功能。
至于怎样显示ascii，我想到查表法，比如点阵字库a在数组中的序号为10，如要显示数组遇到a，则.直接去查找显示10号ascii就行了。
#include "driver/spi_master.h"
#include "driver/gpio.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "string.h"#define PIN_NUM_MOSI 12
#define PIN_NUM_CLK 13
#define PIN_NUM_CS 5
#define PIN_NUM_DC 19
#define PIN_NUM_RST 18spi_device_handle_t spi;void spi_init() {spi_bus_config_t buscfg = {.mosi_io_num = PIN_NUM_MOSI,.miso_io_num = -1,.sclk_io_num = PIN_NUM_CLK,.quadwp_io_num = -1,.quadhd_io_num = -1,.max_transfer_sz = 4096,};spi_bus_initialize(HSPI_HOST, &buscfg, 1);spi_device_interface_config_t devcfg = {.clock_speed_hz = 25 * 1000 * 1000, // 10 MHz.mode = 0, // SPI mode 0.spics_io_num = PIN_NUM_CS, // CS pin.queue_size = 7,};spi_bus_add_device(HSPI_HOST, &devcfg, &spi);
}void st7735_send_cmd(uint8_t cmd) {gpio_set_level(PIN_NUM_DC, 0); // Command modespi_transaction_t t;memset(&t, 0, sizeof(t));t.length = 8;t.tx_buffer = &cmd;spi_device_transmit(spi, &t);
}void st7735_send_data(uint8_t data) {gpio_set_level(PIN_NUM_DC, 1); // Data modespi_transaction_t t;memset(&t, 0, sizeof(t));t.length = 8;t.tx_buffer = &data;spi_device_transmit(spi, &t);
}void st7735_reset() {gpio_set_level(PIN_NUM_RST, 0);vTaskDelay(1 / portTICK_PERIOD_MS);gpio_set_level(PIN_NUM_RST, 1);vTaskDelay(200 / portTICK_PERIOD_MS);
}void st7735_init() {// Reset the displayst7735_reset();// Initialization commands for ST7735Sst7735_send_cmd(0x01); // Software resetvTaskDelay(150 / portTICK_PERIOD_MS);st7735_send_cmd(0x11); // Sleep outvTaskDelay(120 / portTICK_PERIOD_MS);st7735_send_cmd(0xB1);st7735_send_data(0x01);st7735_send_data(0x2c);st7735_send_data(0x2D);st7735_send_cmd(0xB2);st7735_send_data(0x01);st7735_send_data(0x2c);st7735_send_data(0x2D);st7735_send_cmd(0xB3);st7735_send_data(0x01);st7735_send_data(0x2c);st7735_send_data(0x2D);st7735_send_data(0x01);st7735_send_data(0x2c);st7735_send_data(0x2D);st7735_send_cmd(0xB4);st7735_send_data(0x00);st7735_send_cmd(0xc0);st7735_send_data(0xa2);st7735_send_data(0x02);st7735_send_data(0x84);st7735_send_cmd(0xc1);st7735_send_data(0xc5);st7735_send_cmd(0xc2);st7735_send_data(0x0d);st7735_send_cmd(0xc3);st7735_send_data(0x8d);st7735_send_data(0x2a);st7735_send_cmd(0xc4);st7735_send_data(0x8d);st7735_send_data(0xee);st7735_send_cmd(0xc5);st7735_send_data(0x0e);st7735_send_cmd(0x36);st7735_send_data(0b01000000); //40st7735_send_cmd(0xe0);st7735_send_data(0x0f);st7735_send_data(0x1a);st7735_send_data(0x0f);st7735_send_data(0x18);st7735_send_data(0x2f);st7735_send_data(0x28);st7735_send_data(0x20);st7735_send_data(0x22);st7735_send_data(0x1f);st7735_send_data(0x1b);st7735_send_data(0x23);st7735_send_data(0x37);st7735_send_data(0x00);st7735_send_data(0x07);st7735_send_data(0x02);st7735_send_data(0x10);st7735_send_cmd(0xe1);st7735_send_data(0x0f);st7735_send_data(0x1b);st7735_send_data(0x0f);st7735_send_data(0x17);st7735_send_data(0x33);st7735_send_data(0x2c);st7735_send_data(0x29);st7735_send_data(0x2e);st7735_send_data(0x30);st7735_send_data(0x30);st7735_send_data(0x39);st7735_send_data(0x3f);st7735_send_data(0x00);st7735_send_data(0x07);st7735_send_data(0x03);st7735_send_data(0x10);st7735_send_cmd(0x2a);st7735_send_data(0x00);st7735_send_data(0x00);st7735_send_data(0x00);st7735_send_data(127);st7735_send_cmd(0x2b);st7735_send_data(0x00);st7735_send_data(0x00);st7735_send_data(0x00);st7735_send_data(160);st7735_send_cmd(0xf0);st7735_send_data(0x01);st7735_send_cmd(0xf6);st7735_send_data(0x00);st7735_send_cmd(0x3a);st7735_send_data(0x05);st7735_send_cmd(0x29); // Display onvTaskDelay(100 / portTICK_PERIOD_MS);
}void qp(uint8_t xs, uint8_t xe,uint8_t ys,uint8_t ye) {// Set 列st7735_send_cmd(0x2A);st7735_send_data(0x00);st7735_send_data(xs);st7735_send_data(0x00);st7735_send_data(xe);// Set 行st7735_send_cmd(0x2B);st7735_send_data(0x00);st7735_send_data(ys);st7735_send_data(0x00);st7735_send_data(ye);// Write memoryst7735_send_cmd(0x2C);
}void cls(){qp(0,127,0,159); // lcd 全屏刷成白屏for (uint16_t a = 0; a < 159; a++) {for(uint8_t b=0;b<127;b++){st7735_send_data(0xff);st7735_send_data(0xff);}} }
void app_main() {gpio_set_direction(PIN_NUM_DC, GPIO_MODE_OUTPUT);gpio_set_direction(PIN_NUM_RST, GPIO_MODE_OUTPUT);spi_init();st7735_init(); //lcd 初始化后是花屏cls();uint8_t font[][8] ={ {0x1C, 0x22, 0x26, 0x2A, 0x32, 0x22, 0x1C, 0x00}, // '0'{0x04, 0x0C, 0x04, 0x04, 0x04, 0x04, 0x0E, 0x00}, // 数字 '1'{0x0E, 0x11, 0x01, 0x06, 0x08, 0x10, 0x1F, 0x00 }, // 2 {0x1C, 0x22, 0x02, 0x1C, 0x02, 0x22, 0x1C, 0x00}, // '3'{0x08, 0x18, 0x28, 0x48, 0x7E, 0x08, 0x08, 0x00}, // '4'{0x3E, 0x20, 0x3E, 0x02, 0x02, 0x22, 0x1C, 0x00}, // '5'{0x1C, 0x22, 0x20, 0x3C, 0x22, 0x22, 0x1C, 0x00}, // '6'{0x3E, 0x02, 0x04, 0x08, 0x10, 0x20, 0x20, 0x00}, // '7'{0x1C, 0x22, 0x22, 0x1C, 0x22, 0x22, 0x1C, 0x00}, // '8'{0x1C, 0x22, 0x22, 0x1E, 0x02, 0x22, 0x1C, 0x00}, // '9'};void xs(uint8_t ls,uint8_t le,uint8_t hs,uint8_t he,uint8_t *ci){qp(127-le,127-ls,hs,he);for (uint16_t a = 0; a < 8; a++) {for(uint8_t b=0;b<8;b++){if((int)(((ci[a]>>b)&0b00000001))==1){ //如果像素点为1st7735_send_data(0xf8);st7735_send_data(0x00);}else{st7735_send_data(0xff);st7735_send_data(0xff); }}}}uint8_t i[]={6,1,8,3,7,3,6,7,8,7,1,7}; uint16_t len=(int)sizeof(i);uint8_t lc=0; //lcd 显示起始列 uint8_t hc=50; // lcd 显示行for(uint8_t a=0;a<len;a++){uint8_t ls=lc;uint8_t le=ls+7;uint8_t hs=hc; uint8_t he=hs+7; xs(ls,le,hs,he,&font[i[a]][0]);lc=le; //列自动加7，相当于光标后移一个字符}
}
