stm32f407与openmv通信二维码的代码

由于您没有提供更具体的信息，我假设您正在使用OpenMV Cam作为二维码扫描仪，而STM32F407作为主机。

首先，您需要在STM32F407上实现UART通信以与OpenMV Cam进行通信。以下是一个示例代码：

#include "stm32f4xx.h"

#define BAUDRATE 115200

void usart_init(void)
{
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

    GPIO_InitTypeDef GPIO_InitStruct;
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_USART2);

    USART_InitTypeDef USART_InitStruct;
    USART_InitStruct.USART_BaudRate = BAUDRATE;
    USART_InitStruct.USART_WordLength = USART_WordLength_8b;
    USART_InitStruct.USART_StopBits = USART_StopBits_1;
    USART_InitStruct.USART_Parity = USART_Parity_No;
    USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_Init(USART2, &USART_InitStruct);

    USART_Cmd(USART2, ENABLE);
}

void usart_send(char c)
{
    while (USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);
    USART_SendData(USART2, c);
}

char usart_recv(void)
{
    while (USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET);
    return USART_ReceiveData(USART2);
}

int main(void)
{
    usart_init();

    while (1)
    {
        char c = usart_recv();
        // 处理接收到的数据
    }
}

接下来，您需要在OpenMV Cam上实现QR码扫描和串口通信。以下是一个示例代码：

import sensor, image, time, pyb

uart = pyb.UART(3, 115200)

sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False)
sensor.set_auto_whitebal(False)

while True:
    img = sensor.snapshot()
    res = img.find_qrcodes()
    if len(res) > 0:
        for r in res:
            uart.write(r.payload())
            time.sleep(100)

此代码将在串口上输出扫描到的QR码内容。

最后，您需要在STM32F407上实现QR码的解码。您可以使用适用于STM32F4的ZBar库来实现此功能。以下是一个示例代码：

#include "stm32f4xx.h"
#include "ZBarLib.h"

#define BAUDRATE 115200

void usart_init(void)
{
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

    GPIO_InitTypeDef GPIO_InitStruct;
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_USART2);

    USART_InitTypeDef USART_InitStruct;
    USART_InitStruct.USART_BaudRate = BAUDRATE;
    USART_InitStruct.USART_WordLength = USART_WordLength_8b;
    USART_InitStruct.USART_StopBits = USART_StopBits_1;
    USART_InitStruct.USART_Parity = USART_Parity_No;
    USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_Init(USART2, &USART_InitStruct);

    USART_Cmd(USART2, ENABLE);
}

int main(void)
{
    usart_init();
    zbar_processor_t *proc = zbar_processor_create(0);
    zbar_processor_init(proc, "/dev/null", 1);

    while (1)
    {
        char c = USART_ReceiveData(USART2);
        if (c == '\n')
        {
            zbar_processor_set_data(proc, (unsigned char *)buf, strlen(buf), zbar_true);
            zbar_process_image(proc, 0);
            const zbar_symbol_t *symbol = zbar_image_first_symbol(zbar_processor_get_image(proc));
            while (symbol != NULL)
            {
                printf("QR code data: %s\n", zbar_symbol_get_data(symbol));
                symbol = zbar_symbol_next(symbol);
            }
            zbar_image_remove_symbols(zbar_processor_get_image(proc));
            buf[0] = '\0';
        }
        else
        {
            strcat(buf, &c);
        }
    }
}

此代码将从串口接收QR码数据，并解码它们。解码结果将通过调试串口输出。