你是一名STM32的软件开发工程师要求你用STM32F104VE完成下面的题目不能用HAL用标准库函数方式使用GPIO模拟SPI协议在屏幕上显示字母A屏幕分辨率为240280驱动芯片ST7789V3引脚定义PB8 SCLPB9 SDAPB10 RESPB11 DCPB12 CSPB13 BLK

以下是参考代码，仅供参考：

#include "stm32f10x.h"

#define SCL_PIN GPIO_Pin_8 #define SDA_PIN GPIO_Pin_9 #define RES_PIN GPIO_Pin_10 #define DC_PIN GPIO_Pin_11 #define CS_PIN GPIO_Pin_12 #define BLK_PIN GPIO_Pin_13

#define SPI_CLK_FREQ 10000000 // SPI时钟频率，可根据屏幕手册进行调整

void delay_ms(uint32_t ms) { uint32_t i, j; for (i = 0; i < ms; i++) for (j = 0; j < 7200; j++); // 粗略延时1ms，具体值可根据系统时钟频率进行调整 }

void spi_write_byte(uint8_t data) { uint8_t i; for (i = 0; i < 8; i++) { if (data & 0x80) GPIO_SetBits(GPIOB, SDA_PIN); else GPIO_ResetBits(GPIOB, SDA_PIN); GPIO_SetBits(GPIOB, SCL_PIN); data <<= 1; GPIO_ResetBits(GPIOB, SCL_PIN); } }

void spi_write_cmd(uint8_t cmd) { GPIO_ResetBits(GPIOB, DC_PIN); GPIO_ResetBits(GPIOB, CS_PIN); spi_write_byte(cmd); GPIO_SetBits(GPIOB, CS_PIN); }

void spi_write_data(uint8_t data) { GPIO_SetBits(GPIOB, DC_PIN); GPIO_ResetBits(GPIOB, CS_PIN); spi_write_byte(data); GPIO_SetBits(GPIOB, CS_PIN); }

void lcd_init(void) { GPIO_SetBits(GPIOB, BLK_PIN); GPIO_SetBits(GPIOB, RES_PIN); delay_ms(5); GPIO_ResetBits(GPIOB, RES_PIN); delay_ms(20); GPIO_SetBits(GPIOB, RES_PIN); delay_ms(120); spi_write_cmd(0x36); spi_write_data(0x00); spi_write_cmd(0x3A); spi_write_data(0x05); spi_write_cmd(0xB2); spi_write_data(0x0C); spi_write_data(0x0C); spi_write_data(0x00); spi_write_data(0x33); spi_write_data(0x33); spi_write_cmd(0xB7); spi_write_data(0x35); spi_write_cmd(0xBB); spi_write_data(0x2B); spi_write_cmd(0xC0); spi_write_data(0x2C); spi_write_cmd(0xC2); spi_write_data(0x01); spi_write_cmd(0xC3); spi_write_data(0x12); spi_write_cmd(0xC4); spi_write_data(0x20); spi_write_cmd(0xC6); spi_write_data(0x0F); spi_write_cmd(0xD0); spi_write_data(0xA4); spi_write_data(0xA1); spi_write_cmd(0xE0); spi_write_data(0xD0); spi_write_data(0x04); spi_write_data(0x0D); spi_write_data(0x11); spi_write_data(0x13); spi_write_data(0x2B); spi_write_data(0x3F); spi_write_data(0x54); spi_write_data(0x4C); spi_write_data(0x18); spi_write_data(0x0D); spi_write_data(0x0B); spi_write_data(0x1F); spi_write_data(0x23); spi_write_cmd(0xE1); spi_write_data(0xD0); spi_write_data(0x04); spi_write_data(0x0C); spi_write_data(0x11); spi_write_data(0x13); spi_write_data(0x2C); spi_write_data(0x3F); spi_write_data(0x44); spi_write_data(0x51); spi_write_data(0x2F); spi_write_data(0x1F); spi_write_data(0x1F); spi_write_data(0x20); spi_write_data(0x23); spi_write_cmd(0x21); spi_write_cmd(0x11); spi_write_cmd(0x29); }

void lcd_set_window(uint16_t x1, uint16_t y1, uint16_t x2, uint16_t y2) { spi_write_cmd(0x2A); spi_write_data(x1 >> 8); spi_write_data(x1 & 0xFF); spi_write_data(x2 >> 8); spi_write_data(x2 & 0xFF); spi_write_cmd(0x2B); spi_write_data(y1 >> 8); spi_write_data(y1 & 0xFF); spi_write_data(y2 >> 8); spi_write_data(y2 & 0xFF); spi_write_cmd(0x2C); }

void lcd_draw_pixel(uint16_t x, uint16_t y, uint16_t color) { lcd_set_window(x, y, x, y); spi_write_data(color >> 8); spi_write_data(color & 0xFF); }

void lcd_draw_char(uint16_t x, uint16_t y, char ch, uint16_t color) { uint8_t i, j; for (i = 0; i < 16; i++) { for (j = 0; j < 8; j++) { if ((Font16x8[ch - 32][i] >> j) & 0x01) lcd_draw_pixel(x + j, y + i, color); } } }

int main() { RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); GPIO_InitTypeDef GPIO_InitStructure; GPIO_InitStructure.GPIO_Pin = SCL_PIN | SDA_PIN | RES_PIN | DC_PIN | CS_PIN | BLK_PIN; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOB, &GPIO_InitStructure); lcd_init(); lcd_draw_char(0, 0, 'A', 0xFFFF); while (1); return 0; }