写一个r3013mg用串口读取二维码的stm32源码

以下是一个使用STM32通过串口读取r3013mg二维码的示例代码，供参考：

#include "stm32f4xx.h"
#include "stdio.h"
#include "string.h"

UART_HandleTypeDef huart2;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);

void delay_ms(int ms)
{
    for(int i = 0; i < ms; i++)
    {
        for(int j = 0; j < 2000; j++);
    }
}

void r3013mg_send_cmd(char* cmd)
{
    HAL_UART_Transmit(&huart2, (uint8_t*)cmd, strlen(cmd), 1000);
}

void r3013mg_recv_data(char* data, int len)
{
    HAL_UART_Receive(&huart2, (uint8_t*)data, len, 1000);
}

int main(void)
{
    HAL_Init();
    SystemClock_Config();
    MX_GPIO_Init();
    MX_USART2_UART_Init();

    char cmd_init[] = "AT+INIT\r\n";
    r3013mg_send_cmd(cmd_init);
    delay_ms(100);

    char cmd_outputmode[] = "AT+OUTPUTMODE=1\r\n";
    r3013mg_send_cmd(cmd_outputmode);
    delay_ms(100);

    char cmd_uart1tx[] = "AT+UART1TX=1\r\n";
    r3013mg_send_cmd(cmd_uart1tx);
    delay_ms(100);

    char data[64] = {0};
    while (1)
    {
        r3013mg_recv_data(data, 64);
        printf("QR code: %s\n", data);
        memset(data, 0, sizeof(data));
        delay_ms(100);
    }
}

void SystemClock_Config(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

    /** Initializes the RCC Oscillators according to the specified parameters
    * in the RCC_OscInitTypeDef structure.
    */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
    RCC_OscInitStruct.HSIState = RCC_HSI_ON;
    RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    {
        Error_Handler();
    }
    /** Initializes the CPU, AHB and APB buses clocks
    */
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                                |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
    {
        Error_Handler();
    }
}

static void MX_USART2_UART_Init(void)
{
    huart2.Instance = USART2;
    huart2.Init.BaudRate = 115200;
    huart2.Init.WordLength = UART_WORDLENGTH_8B;
    huart2.Init.StopBits = UART_STOPBITS_1;
    huart2.Init.Parity = UART_PARITY_NONE;
    huart2.Init.Mode = UART_MODE_TX_RX;
    huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
    huart2.Init.OverSampling = UART_OVERSAMPLING_16;
    if (HAL_UART_Init(&huart2) != HAL_OK)
    {
        Error_Handler();
    }
}

static void MX_GPIO_Init(void)
{
    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_GPIOB_CLK_ENABLE();
    __HAL_RCC_GPIOC_CLK_ENABLE();
}

该代码使用了STM32的HAL库，通过USART2串口与r3013mg读码器进行通信。在主函数中先发送了一些初始化命令（AT+INIT、AT+OUTPUTMODE=1、AT+UART1TX=1），然后进入一个循环，不断接收r3013mg读码器通过串口输出的数据，并打印出来。

注意，使用该代码需要先将r3013mg读码器连接到STM32的USART2串口，并根据需要修改串口的波特率等配置。另外，该代码仅供参考，具体实现还需根据具体需求进行修改。