STM32与RS485通讯监测有毒气体示例程序

以下是一个基于STM32与RS485通信监测有毒气体的示例程序，你可以根据自己的需求进行修改和扩展：

#include "stm32f4xx.h"
#include "stm32f4xx_hal.h"
#include <string.h>

#define RS485_GPIO_PORT     GPIOA
#define RS485_TX_PIN        GPIO_PIN_9
#define RS485_RX_PIN        GPIO_PIN_10

UART_HandleTypeDef huart;

void RS485_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct = {0};

    // Enable GPIO clock
    __HAL_RCC_GPIOA_CLK_ENABLE();

    // Configure GPIO pins
    GPIO_InitStruct.Pin = RS485_TX_PIN | RS485_RX_PIN;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF7_USART1;
    HAL_GPIO_Init(RS485_GPIO_PORT, &GPIO_InitStruct);

    // Enable USART clock
    __HAL_RCC_USART1_CLK_ENABLE();

    // Configure USART
    huart.Instance = USART1;
    huart.Init.BaudRate = 9600;
    huart.Init.WordLength = UART_WORDLENGTH_8B;
    huart.Init.StopBits = UART_STOPBITS_1;
    huart.Init.Parity = UART_PARITY_NONE;
    huart.Init.Mode = UART_MODE_TX_RX;
    huart.Init.HwFlowCtl = UART_HWCONTROL_NONE;
    huart.Init.OverSampling = UART_OVERSAMPLING_16;
    HAL_UART_Init(&huart);
}

void RS485_SendData(uint8_t* data, uint16_t len)
{
    HAL_GPIO_WritePin(RS485_GPIO_PORT, RS485_TX_PIN, GPIO_PIN_SET);   // Set TX pin high
    HAL_UART_Transmit(&huart, data, len, HAL_MAX_DELAY);
    HAL_GPIO_WritePin(RS485_GPIO_PORT, RS485_TX_PIN, GPIO_PIN_RESET); // Set TX pin low
}

void RS485_ReceiveData(uint8_t* data, uint16_t len)
{
    HAL_GPIO_WritePin(RS485_GPIO_PORT, RS485_TX_PIN, GPIO_PIN_RESET); // Set TX pin low
    HAL_UART_Receive(&huart, data, len, HAL_MAX_DELAY);
    HAL_GPIO_WritePin(RS485_GPIO_PORT, RS485_TX_PIN, GPIO_PIN_SET);   // Set TX pin high
}

int main(void)
{
    uint8_t txData[] = "Hello RS485!";
    uint8_t rxData[50];

    // Initialize RS485
    RS485_Init();

    while (1)
    {
        // Send data
        RS485_SendData(txData, strlen((char*)txData));

        // Delay for receiving response
        HAL_Delay(100);

        // Receive data
        RS485_ReceiveData(rxData, sizeof(rxData));

        // Process received data
        // ...

        HAL_Delay(1000);
    }
}

这个示例程序使用了STM32的USART1串口与RS485模块进行通信。你需要根据实际情况修改引脚定义和串口初始化的参数。在主循环中，它周期性地发送数据并接收响应，并可以在接收数据后进行处理。

请注意，这只是一个简单的示例程序，你需要根据具体的有毒气体传感器和通信协议来进行适当的修改。同时，还需要根据传感器的数据格式和通信协议进行数据解析和处理。