树莓派4b测量PM2.5

1.GP2Y1010AU0F粉尘传感器连接图 

2. GP2Y1010AU0F工作原理

工作原理

传感器中心有个洞可以让空气自由流过，定向发射LED光，通过检测经过空气中灰尘折射过后的光线来判断灰尘的含量。 

3.源代码

main.py

# coding=UTF-8
import RPi.GPIO as GPIO
from ADC import ADS1015
from ADC import ADS_POINTER_CONFIG
import time
import math
import smbus
 
# import serial
 
COV_RATIO = 0.2  # //ug/mmm / mv
NO_DUST_VOLTAGE = 400  # //mv
SYS_VOLTAGE = 5000
 
density = 0.0
voltage = 0.0
 
 
# int adcvalue=0
def SendVideo():
    ads1015 = ADS1015()
    state = ads1015._read_u16(ADS_POINTER_CONFIG) & 0x8000  # 气体传感器连接确立
 
    if (state != 0x8000):
        print("\nADS1015 Error\n")
        # 收集气体数据
 
    GPIO.setmode(GPIO.BOARD)
    IN1 = 16
    GPIO.setwarnings(False)
    GPIO.setup(IN1, GPIO.OUT)  # 初始化二极管灯
    GPIO.output(IN1, GPIO.LOW)  # 关闭二级管灯
    # ser = serial.Serial("/dev/ttyAMA0",9600)
 
    # def Filter(m):
 
    while 1:
        GPIO.output(IN1, GPIO.HIGH)  # 启动二极管灯
        # AIN2_DATA=ads1015.ADS1015_SINGLE_READ(2)
        time.sleep(0.00028)  # 等待0.28ms
 
        AIN2_DATA = ads1015.ADS1015_SINGLE_READ(2)
        # AIN0_DATA=((AIN0_DATA*2-64)/2000.00+0.02)*2
 
        time.sleep(0.00004)  # 持续采集0.04ms
        GPIO.output(IN1, GPIO.LOW)  # 关闭二级管灯
        time.sleep(0.00986)
        voltage = (5000 / 1024.0) * AIN2_DATA * 1.1 * 2  # 计算气体浓度
 
        if (voltage >= NO_DUST_VOLTAGE):
            voltage -= NO_DUST_VOLTAGE
            density = voltage * COV_RATIO
        else:
            density = 0
 
        FG = "The current dust concentration is:" + str(round(density, 2)) + " ug/m3"
        # FG=voltage
        print(FG)
        time.sleep(0.100)
        # F6=FG.encode('utf-8')
 
        # sock.send(str.encode(str(len(F6)).ljust(16)));
        # sock.send(F6)
 
 
if __name__ == '__main__':
    SendVideo()

 ADC.py

#!/usr/bin/python
# -*- coding:utf-8 -*-
import time
import smbus
#i2c address
ADS_I2C_ADDRESS                   = 0x48
 
#Pointer Register
ADS_POINTER_CONVERT               = 0x00 # 指针_转换
ADS_POINTER_CONFIG                = 0x01 # 指针_配置
ADS_POINTER_LOWTHRESH             = 0x02 # 低阈值
ADS_POINTER_HIGHTHRESH            = 0x03 # 高阈值
 
#Config Register
ADS_CONFIG_OS_BUSY                  = 0x0000      #Device is currently performing a conversion 设备当前正在执行转换
ADS_CONFIG_OS_NOBUSY                = 0x8000      #Device is not currently performing a conversion 设备当前没有执行转换
ADS_CONFIG_OS_SINGLE_CONVERT        = 0x8000      #Start a single conversion (when in power-down state) 开始单次转换(在掉电状态下)
ADS_CONFIG_OS_NO_EFFECT             = 0x0000      #No effect 没有效果
ADS_CONFIG_MUX_MUL_0_1              = 0x0000      #Input multiplexer,AINP = AIN0 and AINN = AIN1(default 系统默认值) 输入复用器
ADS_CONFIG_MUX_MUL_0_3              = 0x1000      #Input multiplexer,AINP = AIN0 and AINN = AIN3 输入复用器
ADS_CONFIG_MUX_MUL_1_3              = 0x2000      #Input multiplexer,AINP = AIN1 and AINN = AIN3 输入复用器
ADS_CONFIG_MUX_MUL_2_3              = 0x3000      #Input multiplexer,AINP = AIN2 and AINN = AIN3 输入复用器
ADS_CONFIG_MUX_SINGLE_0             = 0x4000      #SINGLE,AIN0
ADS_CONFIG_MUX_SINGLE_1             = 0x5000      #SINGLE,AIN1
ADS_CONFIG_MUX_SINGLE_2             = 0x6000      #SINGLE,AIN2
ADS_CONFIG_MUX_SINGLE_3             = 0x7000      #SINGLE,AIN3
ADS_CONFIG_PGA_6144                 = 0x0000      #Gain= +/- 6.144V
ADS_CONFIG_PGA_4096                 = 0x0200      #Gain= +/- 4.096V
ADS_CONFIG_PGA_2048                 = 0x0400      #Gain= +/- 2.048V(default) 偏差正负2
ADS_CONFIG_PGA_1024                 = 0x0600      #Gain= +/- 1.024V
ADS_CONFIG_PGA_512                  = 0x0800      #Gain= +/- 0.512V
ADS_CONFIG_PGA_256                  = 0x0A00      #Gain= +/- 0.256V
ADS_CONFIG_MODE_CONTINUOUS          = 0x0000      #Device operating mode:Continuous-conversion mode 设备运行模式:连续转换模式
ADS_CONFIG_MODE_NOCONTINUOUS        = 0x0100      #Device operating mode：Single-shot mode or power-down state (default) 设备运行模式:单发模式或掉电状态(默认)
ADS_CONFIG_DR_RATE_128              = 0x0000      #Data rate=128SPS 数据率
ADS_CONFIG_DR_RATE_250              = 0x0020      #Data rate=250SPS
ADS_CONFIG_DR_RATE_490              = 0x0040      #Data rate=490SPS
ADS_CONFIG_DR_RATE_920              = 0x0060      #Data rate=920SPS
ADS_CONFIG_DR_RATE_1600             = 0x0080      #Data rate=1600SPS
ADS_CONFIG_DR_RATE_2400             = 0x00A0      #Data rate=2400SPS
ADS_CONFIG_DR_RATE_3300             = 0x00C0      #Data rate=3300SPS
ADS_CONFIG_COMP_MODE_WINDOW         = 0x0010      #Comparator mode：Window comparator 比较器模式:窗口比较器
ADS_CONFIG_COMP_MODE_TRADITIONAL    = 0x0000      #Comparator mode：Traditional comparator (default) 比较器模式:传统比较器(默认)
ADS_CONFIG_COMP_POL_LOW             = 0x0000      #Comparator polarity：Active low (default) 比较器极性:低电平有效(默认)
ADS_CONFIG_COMP_POL_HIGH            = 0x0008      #Comparator polarity：Active high
ADS_CONFIG_COMP_LAT                 = 0x0004      #Latching comparator  锁存比较器
ADS_CONFIG_COMP_NONLAT              = 0x0000      #Nonlatching comparator (default) 无锁存
ADS_CONFIG_COMP_QUE_ONE             = 0x0000      #Assert after one conversion 一次转换后断言
ADS_CONFIG_COMP_QUE_TWO             = 0x0001      #Assert after two conversions 两次转换后断言
ADS_CONFIG_COMP_QUE_FOUR            = 0x0002      #Assert after four conversions 四次转换后断言
ADS_CONFIG_COMP_QUE_NON             = 0x0003      #Disable comparator and set ALERT/RDY pin to high-impedance (default) 禁用比较器并将ALERT/RDY引脚设置为高阻抗(默认)
 
Config_Set = 0
 
class ADS1015(object):
    def __init__(self,address=ADS_I2C_ADDRESS):
        self._address = address
        self._bus = smbus.SMBus(1)
    def ADS1015_SINGLE_READ(self,channel):                    #Read single channel data 读取单通道数据
        data=0
        Config_Set =  ( ADS_CONFIG_MODE_NOCONTINUOUS        |   #mode：Single-shot mode or power-down state    (default) 模式:单触发模式或掉电状态
                        ADS_CONFIG_PGA_4096                 |   #Gain= +/- 4.096V                              (default)
                        ADS_CONFIG_COMP_QUE_NON             |   #Disable comparator                            (default)
                        ADS_CONFIG_COMP_NONLAT              |   #Nonlatching comparator                        (default)
                        ADS_CONFIG_COMP_POL_LOW             |   #Comparator polarity：Active low               (default)
                        ADS_CONFIG_COMP_MODE_TRADITIONAL    |   #Traditional comparator                        (default)
                        ADS_CONFIG_DR_RATE_1600             )   #Data rate=1600SPS                             (default)
        if channel == 0:
            Config_Set |= ADS_CONFIG_MUX_SINGLE_0
        elif channel == 1:
            Config_Set |= ADS_CONFIG_MUX_SINGLE_1
        elif channel == 2:
            Config_Set |= ADS_CONFIG_MUX_SINGLE_2
        elif channel == 3:
            Config_Set |= ADS_CONFIG_MUX_SINGLE_3
        Config_Set |=ADS_CONFIG_OS_SINGLE_CONVERT
        self._write_word(ADS_POINTER_CONFIG,Config_Set)
        #time.sleep(0.01)
        data=self._read_u16(ADS_POINTER_CONVERT)>>4
        #print(data)
        return data
    def _read_u16(self,cmd):
        LSB = self._bus.read_byte_data(self._address,cmd)
        MSB = self._bus.read_byte_data(self._address,cmd+1)
        print((LSB << 8) + MSB,'----------')
        return (LSB << 8) + MSB
    def _write_word(self, cmd, val):
        Val_H=val&0xff
        Val_L=val>>8
        val=(Val_H<<8)|Val_L
        self._bus.write_word_data(self._address,cmd,val)