File content as of revision 1:0e75de2a5d21:

//#include <SoftwareSerial.h>
//#include <AM2321.h>
#include "MicroduinoPinNames.h"

#define INTERVAL_pm25             200
unsigned long pm25_time = 0;

//SoftwareSerial pmSerial(4,5);   //PM2.5传感器通讯软串口
Serial pmSerial(D4, D5); //rx,tx
AnalogIn gLight(A0);
AnalogIn gCH4(A2);
//AM2321 am2321;

float sensor_tem,sensor_hum,sensor_light,Sensor_etoh;

float sensorPM25;

long map(long x, long in_min, long in_max, long out_min, long out_max)
{
    return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}

// 读取PM2.5传感器
float PM25()
{
    int data_s = 0;    //串口接收数据
    int num = -1;      //串口接收数据计数
    int sum = 0;       //校验和
    int cal[6];        //接收数据缓存
    float dustDensity = 0;  //PM2.5浓度

    //pmSerial.begin(2400);   //首先启动软串口
    pmSerial.baud(2400);
    //pmSerial.flush();       //清空串口缓存

    while(1) {
        //if(pmSerial.available() > 0) { //串口缓存有数据
        if (pmSerial.readable() > 0) {
            //data_s = pmSerial.read();   //读取串口缓存数据
            data_s = pmSerial.getc();
            if(data_s == 0xAA) {         //得到数据帧起始位
                num = 0;                  //开始计数
            } else if(num >= 0) {
                num++;                //读到数据，计数+1
                cal[num-1] = data_s;  //数据保存到缓存中
                if(num == 6) {         //读到数据帧最后一位
                    sum = cal[0] + cal[1] + cal[2] + cal[3];  //计算校验和
                    if(sum == cal[4] && cal[5] == 0xFF) {     //校验和匹配，数据帧最后一位为0xFF，说明接收的数据帧正常
                        dustDensity = (cal[0]*256 + cal[1])*(5.0/1024)*550;   //计算PM2.5浓度，单位ug/m3
                    } else {   //接收的数据不正常
                        dustDensity = 0;    //浓度清零
                    }
                    break;
                }
            }
        }
    }
    //pmSerial.end();     //关闭软串口
    return dustDensity; //返回值
}

// 读取光照传感器
void updateLight()
{
    //sensor_light = map(analogRead(A0), 0, 1023, 0, 255);
    sensor_light = map(gLight.read_u16(), 0, 65535, 0, 255);
}

// 读取甲醛传感器
void updateCH4()
{
    //Sensor_etoh = map(analogRead(A2), 0, 1023, 0, 30);
    Sensor_etoh = map(gCH4.read_u16(), 0, 65535, 0, 30);
}

// 读取温湿度传感器
void updateTempHumi()
{
#if 0
    am2321.read();
    sensor_tem = am2321.temperature / 10.0;
    sensor_hum = am2321.humidity / 10.0;
#endif
}