Difference between revisions of "Dust Sensor"

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== Usage  ==
 
== Usage  ==
 
Here is a demo to show you how to obtain PM concentration data from this Grove - Dust Sensor.
 
 
1. Plug the dust sensor into digital port D8 on the [[Grove - Base Shield]]. It can only be D8, because the operation of this sensor involves sampling, a function only can be achieved by D8, the capture input pin of Atmage328P, on Arduino/Seeeduino.&nbsp;<br>
 
[[File:Dust Sensor Connector.jpg|700px]]<br>
 
2. Copy and paste the demo code below to a new Arduino sketch.
 
<pre>/* Grove - Dust Sensor Demo v1.0
 
Interface to Shinyei Model PPD42NS Particle Sensor
 
Program by Christopher Nafis
 
Written April 2012
 
 
http://www.sca-shinyei.com/pdf/PPD42NS.pdf
 
 
JST Pin 1 (Black Wire)  =&gt; Arduino GND
 
JST Pin 3 (Red wire)    =&gt; Arduino 5VDC
 
JST Pin 4 (Yellow wire) =&gt; Arduino Digital Pin 8
 
*/
 
 
int pin = 8;
 
unsigned long duration;
 
unsigned long starttime;
 
unsigned long sampletime_ms = 30000;//sampe 30s&nbsp;;
 
unsigned long lowpulseoccupancy = 0;
 
float ratio = 0;
 
float concentration = 0;
 
 
void setup() {
 
  Serial.begin(9600);
 
  pinMode(8,INPUT);
 
  starttime = millis();//get the current time;
 
}
 
 
void loop() {
 
  duration = pulseIn(pin, LOW);
 
  lowpulseoccupancy = lowpulseoccupancy+duration;
 
 
  if ((millis()-starttime) &gt; sampletime_ms)//if the sampel time == 30s
 
  {
 
    ratio = lowpulseoccupancy/(sampletime_ms*10.0);  // Integer percentage 0=&gt;100
 
    concentration = 1.1*pow(ratio,3)-3.8*pow(ratio,2)+520*ratio+0.62; // using spec sheet curve
 
    Serial.print(lowpulseoccupancy);
 
    Serial.print(",");
 
    Serial.print(ratio);
 
    Serial.print(",");
 
    Serial.println(concentration);
 
    lowpulseoccupancy = 0;
 
    starttime = millis();
 
  }
 
}</pre>
 
In this program, the seeeduino samples the total duration of "logic low" in 30s, and this duration illustrates the dust density of environment. Open serial monitor, we can read air quality's value detected by sensor from pc serial port.<br> [[Image:Dust Sensor Output Score.jpg]]
 
 
The result above consists of three parts: lowpulseoccupancy, ratio and concentration.
 
 
"lowpulseoccupancy" represents the Lo Pulse Occupancy Time(LPO Time) detected in given 30s. Its unit is microsecond.
 
 
"ratio" reflects on which level LPO Time takes up the whole sample time.
 
 
"concentration" is a figure that has physical meaning. It's calculated from the characteristic graph below by using the LPO time.<br> [[Image:Characteristics.jpg|550px|Characteristics.jpg]]<br>
 
  
 
== Resources ==
 
== Resources ==
  
 
[http://www.howmuchsnow.com/arduino/airquality/grovedust/ Example of uploading data from dust sensor to Cosm.]
 
[http://www.howmuchsnow.com/arduino/airquality/grovedust/ Example of uploading data from dust sensor to Cosm.]

Revision as of 00:12, 25 December 2013



Introduction

This Dust Sensor measures the Particulate Matter level in air by counting the Lo Pulse Occupancy time(LPO time) in given time unit. LPO time is in proportion to PM concentration. This sensor can provide you pretty reliable data for your PM2.5 project or air purifier system because it's still responsive to particulates whose diameter is 1um.

Dustsensor.JPG


Features

  • Highly responsive
  • Reliable
  • ROHS/PEACH compliant

Note: New version updates output Hi Voltage from Approx. over 4.0V change to Approx over 4.5V.

Application Ideas

Cautions

  • Please keep it upright.
  • 3 min preheat time is required when used at the first time.
  • Arbitrary operation may cause unexpected damage.
  • Pins VR1 and VR2 come preset. Please DON'T change the default configuration.

Specification

Items Min Norm Max Unit
VCC 4.75 - 5.25 V
Standby Current Supply - 90 - mA
Detectable range of concentration - 0~28,000 - pcs/liter
Operating Temperature Range 0 - 45 °C
Output Method Negative Logic, Digital output,Hi over 4.0V(Rev.2) Lo: under 0.7V
Detecting the particle diameter >1 um
Dimensions 59(W) × 45(H) × 22(D) [mm]
Humidity Range 95%rh or less


Usage

Resources

Example of uploading data from dust sensor to Cosm.