st7789v2 240x320驱动

ST7789V2是一款240x320分辨率的TFT液晶驱动IC。以下是一个简单的C语言示例代码，可以用于驱动ST7789V2：

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>

#include "st7789v2.h"

#define DELAY(ms) \
    do { \
        volatile uint32_t n = (SystemCoreClock / 1000) * (ms); \
        while (n--) \
            __NOP(); \
    } while (0)

#define SPI_TIMEOUT 5000

static void spi_write(uint8_t data)
{
    while (!(SPI2->SR & SPI_SR_TXE))
        ;
    *(volatile uint8_t *)&SPI2->DR = data;
    while (!(SPI2->SR & SPI_SR_RXNE))
        ;
    while (SPI2->SR & SPI_SR_BSY)
        ;
    (void)SPI2->DR;
}

static void spi_write16(uint16_t data)
{
    spi_write(data >> 8);
    spi_write(data & 0xFF);
}

static void spi_write_command(uint8_t cmd)
{
    GPIOB->BSRR = GPIO_BSRR_BR1; // DC low
    spi_write(cmd);
    GPIOB->BSRR = GPIO_BSRR_BS1; // DC high
}

static void spi_write_data(uint8_t data)
{
    spi_write(data);
}

static void spi_write_data16(uint16_t data)
{
    GPIOB->BSRR = GPIO_BSRR_BS1; // DC high
    spi_write16(data);
}

void st7789v2_init(void)
{
    uint8_t data;

    RCC->AHBENR |= RCC_AHBENR_GPIOBEN;
    RCC->APB1ENR |= RCC_APB1ENR_SPI2EN;

    // PB12 = SPI2_NSS
    GPIOB->MODER |= GPIO_MODER_MODER12_0;

    // PB13 = SPI2_SCK, PB14 = SPI2_MISO, PB15 = SPI2_MOSI
    GPIOB->MODER |= GPIO_MODER_MODER13_1 | GPIO_MODER_MODER14_1 | GPIO_MODER_MODER15_1;
    GPIOB->AFR[1] |= (5 << (1 * 4)) | (5 << (2 * 4)) | (5 << (3 * 4));

    SPI2->CR1 = SPI_CR1_SSM | SPI_CR1_SSI | SPI_CR1_MSTR | SPI_CR1_BR_0 | SPI_CR1_BR_1;
    SPI2->CR2 = SPI_CR2_DS_2 | SPI_CR2_DS_1 | SPI_CR2_DS_0;
    SPI2->CR1 |= SPI_CR1_SPE;

    // Reset display
    GPIOB->BSRR = GPIO_BSRR_BR0; // Reset low
    DELAY(50);
    GPIOB->BSRR = GPIO_BSRR_BS0; // Reset high
    DELAY(50);

    // Initialize display
    spi_write_command(0x11); // Exit sleep mode
    DELAY(120);

    spi_write_command(0x3A); // Set pixel format
    spi_write_data(0x55);

    spi_write_command(0xB2); // Set display mode
    spi_write_data(0x0C);
    spi_write_data(0x0C);
    spi_write_data(0x00);
    spi_write_data(0x33);
    spi_write_data(0x33);

    spi_write_command(0xB7); // Set vertical scroll
    spi_write_data(0x35);

    spi_write_command(0xBB); // Set display inversion
    spi_write_data(0x2B);

    spi_write_command(0xC0); // Set power control
    spi_write_data(0x2C);

    spi_write_command(0xC2); // Set VCOM
    spi_write_data(0x01);
    spi_write_data(0xFF);

    spi_write_command(0xC3); // Set VDV and VRH command enable
    spi_write_data(0x11);

    spi_write_command(0xC4); // Set VDV and VRH values
    spi_write_data(0x20);
    spi_write_data(0x00);

    spi_write_command(0xC6); // Set frame rate
    spi_write_data(0x0F);

    spi_write_command(0xD0); // Set panel driving
    spi_write_data(0xA4);
    spi_write_data(0xA1);

    spi_write_command(0xE0); // Set gamma curve
    spi_write_data(0xD0);
    spi_write_data(0x08);
    spi_write_data(0x11);
    spi_write_data(0x08);
    spi_write_data(0x0C);
    spi_write_data(0x15);
    spi_write_data(0x39);
    spi_write_data(0x33);
    spi_write_data(0x50);
    spi_write_data(0x36);
    spi_write_data(0x13);
    spi_write_data(0x14);
    spi_write_data(0x29);
    spi_write_data(0x2D);

    spi_write_command(0xE1); // Set gamma curve
    spi_write_data(0xD0);
    spi_write_data(0x08);
    spi_write_data(0x10);
    spi_write_data(0x08);
    spi_write_data(0x06);
    spi_write_data(0x06);
    spi_write_data(0x39);
    spi_write_data(0x44);
    spi_write_data(0x51);
    spi_write_data(0x0B);
    spi_write_data(0x16);
    spi_write_data(0x14);
    spi_write_data(0x2F);
    spi_write_data(0x31);

    spi_write_command(0x29); // Display on
}

void st7789v2_set_window(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1)
{
    spi_write_command(0x2A); // Set column address
    spi_write_data16(x0);
    spi_write_data16(x1);

    spi_write_command(0x2B); // Set page address
    spi_write_data16(y0);
    spi_write_data16(y1);

    spi_write_command(0x2C); // Memory write
}

void st7789v2_write_pixel(uint16_t color)
{
    spi_write_data16(color);
}

void st7789v2_fill_screen(uint16_t color)
{
    uint16_t x, y;

    st7789v2_set_window(0, 0, 239, 319);

    for (y = 0; y < 320; y++) {
        for (x = 0; x < 240; x++) {
            st7789v2_write_pixel(color);
        }
    }
}

该代码假设SPI2接口已经初始化，并且PB0和PB1用于复位和DC控制引脚。要使用该代码，只需调用`st7789v2_init()`来初始化液晶屏幕。要在屏幕上绘制像素，首先必须调用`st7789v2_set_window()`设置要绘制像素的窗口，然后使用`st7789v2_write_pixel()`写入像素值。要在屏幕上绘制图形，可以使用`st7789v2_fill_screen()`函数填充整个屏幕。