编写一份基于stm32f103的MQ-2烟雾传感器检测代码，检测到的数据在液晶屏上显示，分为主函数.c和.h文件

以下是一个基于 STM32F103 和 MQ-2 烟雾传感器的检测代码，数据在液晶屏上显示，分为主函数.c和.h文件：

### 烟雾传感器 MQ-2.h

#ifndef __MQ2_H
#define __MQ2_H

#include "stm32f10x.h"

#define         ADC_CHANNEL         0
#define         ADC_GPIO_PORT       GPIOA
#define         ADC_GPIO_PIN        GPIO_Pin_0
#define         ADC_GPIO_CLK        RCC_APB2Periph_GPIOA
#define         ADC1_CLK            RCC_APB2Periph_ADC1

void MQ2_Init(void);
u16 MQ2_GetADCValue(void);
u8 MQ2_Detect(void);
float MQ2_GetPPM(u16 adc_value);

#endif /* __MQ2_H */

### 烟雾传感器 MQ-2.c

#include "MQ2.h"

void MQ2_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    ADC_InitTypeDef ADC_InitStructure;

    /* Enable ADC1 and GPIOA clock */
    RCC_APB2PeriphClockCmd(ADC1_CLK | ADC_GPIO_CLK, ENABLE);

    /* Configure ADC1 Channel0 as analog input */
    GPIO_InitStructure.GPIO_Pin = ADC_GPIO_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
    GPIO_Init(ADC_GPIO_PORT, &GPIO_InitStructure);

    /* ADC1 configuration */
    ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;
    ADC_InitStructure.ADC_ScanConvMode = DISABLE;
    ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
    ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStructure.ADC_NbrOfChannel = 1;
    ADC_Init(ADC1, &ADC_InitStructure);

    /* ADC1 regular channel0 configuration */
    ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_55Cycles5);

    /* Enable ADC1 */
    ADC_Cmd(ADC1, ENABLE);
}

u16 MQ2_GetADCValue(void)
{
    u16 adc_value;

    /* Start ADC1 Software Conversion */
    ADC_SoftwareStartConvCmd(ADC1, ENABLE);

    /* Wait until ADC1 conversion is complete */
    while (ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == RESET);

    /* Get ADC1 converted data */
    adc_value = ADC_GetConversionValue(ADC1);

    return adc_value;
}

u8 MQ2_Detect(void)
{
    u8 status = 0;
    u16 adc_value = MQ2_GetADCValue();

    if (adc_value > 1000) {
        status = 1; /* Detected */
    } else {
        status = 0; /* Not detected */
    }

    return status;
}

float MQ2_GetPPM(u16 adc_value)
{
    float ppm = 0;

    /* Calculate PPM value */
    ppm = 0.3 * adc_value / 4096.0 * 1000000.0;

    return ppm;
}

### 主函数.c

#include "MQ2.h"
#include "lcd.h"
#include <stdio.h>

int main(void)
{
    u8 status = 0;
    u16 adc_value = 0;
    float ppm = 0;

    /* Initialize MQ-2 sensor */
    MQ2_Init();

    /* Initialize LCD */
    LCD_Init();

    LCD_Clear();

    while (1) {
        /* Detect smoke */
        status = MQ2_Detect();

        if (status == 1) {
            adc_value = MQ2_GetADCValue();
            ppm = MQ2_GetPPM(adc_value);
            printf("Smoke detected! PPM: %f\n", ppm);
            LCD_ShowString(0, 0, "Smoke detected!  ");
            LCD_ShowNum(0, 1, (int)ppm, 4, 12);
            LCD_ShowString(54, 1, "PPM");
        } else {
            printf("Smoke not detected.\n");
            LCD_ShowString(0, 0, "Smoke not detected.");
            LCD_ShowString(0, 1, "                ");
        }
    }
}

请注意，这只是一个简单的测试代码，仅供参考。如果您需要进行更严格的烟雾检测，请根据您的具体应用场景进行更改。同时，液晶屏的初始化和显示需要根据您具体的液晶屏型号进行更改。