Introduction: PcDuino Can Help You Measure Air Particle Pollution PM2.5

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In this tutorial we are going to use Dust sensor on pcDuino to measure air pollution pm2.5.

Step 1: Dust Sensor

Main feature：

Output signal is PWM；
Easy installation；
Single-supply；
Parameter：

5VDC；
Scope of detecting particles：Max 8000pcs/283ml；

Step 2: Compile and Run

Hardware：

1 x pcDuino
1 x Dust Sensor
Several jumper wire
Wiring diagram：

Dust Sensor Pin 1  => pcDuino GND
Dust Sensor Pin 3  => pcDuino 5V
Dust Sensor Pin 4  => pcDuino D8v

Step 3: Run Code

Run code： (You need to preheat the dust sensor more than 3 minutes before first use )

1. Launch Arduino IDE  that comes with  pcDuino and enter the following code (the code is shown in next tab)：

Step 4: 2. Click the Run Button

2. Click the run button:

Step 5: Sample Code

<code>

/************************************/
/* Dust Sensor Pin 1 => pcDuino GND */
/* Dust Sensor Pin 3 => pcDuino 5V */
/* Dust Sensor Pin 4 => pcDuino D8 */
/************************************/

int pin = 8;
unsigned long duration;
unsigned long starttime;
unsigned long sampletime_ms = 30000;//sampe 30s ;
unsigned long lowpulseoccupancy = 0;
float ratio = 0;
float concentration = 0;

void setup()
{
pinMode(pin,INPUT);
starttime = millis();//get the current time;
}

void loop()
{
duration = pulseIn(pin,LOW,1000000);
lowpulseoccupancy += duration;

if ((millis()-starttime) > sampletime_ms)//if the sampel time == 30s
{
ratio = lowpulseoccupancy/(sampletime_ms*10.0); // Integer percentage 0=>100
concentration = 1.1*pow(ratio,3)-3.8*pow(ratio,2)+520*ratio+0.62; // using spec sheet curve
printf(“lowpulseoccupancy: %ld \nratio: %f \nconcentration: %f\n\n”,lowpulseoccupancy,ratio,concentration);
lowpulseoccupancy = 0;
starttime = millis();
}
}

</code>