夏普GP2Y1010AU0F灰尘传感器价格较便宜,能检测出室内空气中的灰尘和烟尘含量。另外还有韩国SYHITECH生产的DSM501A粉尘传感器也有类似功能。
检测原理
其原理如下图,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。
电路图
因为数据是通过pin 5的电压模拟信号输出的,而树莓派的引脚不支持模拟信号直接读取(需要增加数模转换芯片),所以先用Arduino来实验。
Arduino 代码
根据电路图, 把Arduino和传感器连接起来:
- Sharp pin 1 (V-LED) => 5V 串联1个150欧姆的电阻(最好在电阻一侧和GND之间再串联一个220uf的电容)
- Sharp pin 2 (LED-GND) => GND
- Sharp pin 3 (LED) => Arduino PIN 2 (开关LED)
- Sharp pin 4 (S-GND) => GND
- Sharp pin 5 (Vo) => Arduino A0 pin (空气质量数据通过电压模拟信号输出)
- Sharp pin 6 (Vcc) => 5V
/*
Interface to Sharp GP2Y1010AU0F Particle Sensor
Program by Christopher Nafis
Written April 2012
http://www.sparkfun.com/datasheets/Sensors/gp2y1010au_e.pdf
http://sensorapp.net/?p=479
Sharp pin 1 (V-LED) => 5V (connected to 150ohm resister)
Sharp pin 2 (LED-GND) => Arduino GND pin
Sharp pin 3 (LED) => Arduino pin 2
Sharp pin 4 (S-GND) => Arduino GND pin
Sharp pin 5 (Vo) => Arduino A0 pin
Sharp pin 6 (Vcc) => 5V
*/
#include <SPI.h>
#include <stdlib.h>
int dustPin=0;
int ledPower=2;
int delayTime=280;
int delayTime2=40;
float offTime=9680;
int dustVal=0;
int i=0;
float ppm=0;
char s[32];
float voltage = 0;
float dustdensity = 0;
float ppmpercf = 0;
void setup(){
Serial.begin(9600);
pinMode(ledPower,OUTPUT);
// give the ethernet module time to boot up:
delay(1000);
i=0;
ppm =0;
}
void loop(){
i=i+1;
digitalWrite(ledPower,LOW); // power on the LED
delayMicroseconds(delayTime);
dustVal=analogRead(dustPin); // read the dust value
ppm = ppm+dustVal;
delayMicroseconds(delayTime2);
digitalWrite(ledPower,HIGH); // turn the LED off
delayMicroseconds(offTime);
voltage = ppm/i*0.0049;
dustdensity = 0.17*voltage-0.1;
ppmpercf = (voltage-0.0256)*120000;
if (ppmpercf < 0)
ppmpercf = 0;
if (dustdensity < 0 )
dustdensity = 0;
if (dustdensity > 0.5)
dustdensity = 0.5;
String dataString = "";
dataString += dtostrf(voltage, 9, 4, s);
dataString += ",";
dataString += dtostrf(dustdensity, 5, 2, s);
dataString += ",";
dataString += dtostrf(ppmpercf, 8, 0, s);
i=0;
ppm=0;
Serial.println(dataString);
delay(1000);
}
把传感器和Ardiuno连接好后,可以连续打印出传感器的输出电压值。输出电压大小和灰尘含量的曲线入下图:
通过电压的波形还可以判断是烟还是尘呢。。。
参考链接
- Sharp GP2Y1010AU0F Data Sheet
- Sharp GP2Y1010AU0F Application Note
- http://www.howmuchsnow.com/arduino/airquality/