编写STM32F407并口驱动LCD1602代码

以下是一个简单的STM32F407并口驱动LCD1602的代码示例：

#include "stm32f4xx.h"

#define LCD_RS_PIN GPIO_Pin_0
#define LCD_RW_PIN GPIO_Pin_1
#define LCD_EN_PIN GPIO_Pin_2
#define LCD_DB4_PIN GPIO_Pin_4
#define LCD_DB5_PIN GPIO_Pin_5
#define LCD_DB6_PIN GPIO_Pin_6
#define LCD_DB7_PIN GPIO_Pin_7

void LCD_Init(void);
void LCD_SendCommand(uint8_t command);
void LCD_SendData(uint8_t data);
void LCD_SendString(char *str);

int main(void) {
    LCD_Init();
    LCD_SendString("Hello, world!");
    while(1);
}

void LCD_Init(void) {
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

    GPIO_InitTypeDef GPIO_InitStruct;
    GPIO_InitStruct.GPIO_Pin = LCD_RS_PIN | LCD_RW_PIN | LCD_EN_PIN | LCD_DB4_PIN | LCD_DB5_PIN | LCD_DB6_PIN | LCD_DB7_PIN;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_WriteBit(GPIOA, LCD_RS_PIN, Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_RW_PIN, Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_EN_PIN, Bit_RESET);

    LCD_SendCommand(0x33);
    LCD_SendCommand(0x32);
    LCD_SendCommand(0x28);
    LCD_SendCommand(0x0C);
    LCD_SendCommand(0x06);
    LCD_SendCommand(0x01);
    LCD_SendCommand(0x02);
}

void LCD_SendCommand(uint8_t command) {
    GPIO_WriteBit(GPIOA, LCD_RS_PIN, Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_RW_PIN, Bit_RESET);

    GPIO_WriteBit(GPIOA, LCD_DB4_PIN, (command & 0x10) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB5_PIN, (command & 0x20) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB6_PIN, (command & 0x40) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB7_PIN, (command & 0x80) ? Bit_SET : Bit_RESET);

    GPIO_WriteBit(GPIOA, LCD_EN_PIN, Bit_SET);
    GPIO_WriteBit(GPIOA, LCD_EN_PIN, Bit_RESET);

    GPIO_WriteBit(GPIOA, LCD_DB4_PIN, (command & 0x01) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB5_PIN, (command & 0x02) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB6_PIN, (command & 0x04) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB7_PIN, (command & 0x08) ? Bit_SET : Bit_RESET);

    GPIO_WriteBit(GPIOA, LCD_EN_PIN, Bit_SET);
    GPIO_WriteBit(GPIOA, LCD_EN_PIN, Bit_RESET);

    // Wait for command to be processed
    for (volatile uint32_t i = 0; i < 1000; i++);
}

void LCD_SendData(uint8_t data) {
    GPIO_WriteBit(GPIOA, LCD_RS_PIN, Bit_SET);
    GPIO_WriteBit(GPIOA, LCD_RW_PIN, Bit_RESET);

    GPIO_WriteBit(GPIOA, LCD_DB4_PIN, (data & 0x10) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB5_PIN, (data & 0x20) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB6_PIN, (data & 0x40) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB7_PIN, (data & 0x80) ? Bit_SET : Bit_RESET);

    GPIO_WriteBit(GPIOA, LCD_EN_PIN, Bit_SET);
    GPIO_WriteBit(GPIOA, LCD_EN_PIN, Bit_RESET);

    GPIO_WriteBit(GPIOA, LCD_DB4_PIN, (data & 0x01) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB5_PIN, (data & 0x02) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB6_PIN, (data & 0x04) ? Bit_SET : Bit_RESET);
    GPIO_WriteBit(GPIOA, LCD_DB7_PIN, (data & 0x08) ? Bit_SET : Bit_RESET);

    GPIO_WriteBit(GPIOA, LCD_EN_PIN, Bit_SET);
    GPIO_WriteBit(GPIOA, LCD_EN_PIN, Bit_RESET);

    // Wait for data to be processed
    for (volatile uint32_t i = 0; i < 1000; i++);
}

void LCD_SendString(char *str) {
    while (*str) {
        LCD_SendData(*str++);
    }
}

这个代码使用了GPIOA作为LCD1602的并口，其他GPIO也可以使用，只需要修改代码中的相应定义。在`main`函数中，我们初始化LCD并发送一串字符串。`LCD_Init`函数初始化GPIO并发送LCD的初始化命令，`LCD_SendCommand`函数发送LCD命令，`LCD_SendData`函数发送LCD数据，`LCD_SendString`函数发送一个字符串（通过调用`LCD_SendData`函数）。在发送命令和数据时，我们需要按照LCD的时序要求进行操作，并且需要适当的延时来确保命令和数据被正确处理。