Reporting PM2.5 PM10 micro particle dust sensor by using Arduino and LoRaWAN ATIM ACW-DUINO shield

Home Labs Stories Reporting PM2.5 PM10 micro particle dust sensor by using Arduino and LoRaWAN ATIM ACW-DUINO shield

by Bruno QUEGUINEUR

ABOUT THIS STORY

Posted on Jan. 7, 2020

#Node #PM2.5 #arduino #Cayenne #Device #ATIM #ARM-N8-LW #Sensor #ACW-DUINO #Luftdaten #MP10 #2560 #Mega #SDS011 #myDevice

Intermediate

2 Days

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Introduction

In this story, a SDS011 sensor is used to measure micro particle contamination.
Each mesure is a couple of values : PM2.5 rate and PM10 rate (µg/m³)
Measures are read by an Arduino, and uplinked to TTN by using a LoRaWAN ATIM ACW-DUINO shield.
Our payloads use Cayenne LPP format.
Measurements can be viewed on Cayenne myDevice account.

NB :
The arduino board uses Pin 0 (Rx) and 1 (Tx) UART to communicate with ACW-DUINO shield.
This UART is also used to uplink sketches from computer (Arduino IDE) to the Arduino board.
Therefore, Arduino sketches must be uploaded to the Arduino board bebore pluging ACW-DUINO shield onto the Arduino board

Uploading sketch to the Arduino board

The ATIM library is provided with examples.

The ATIM LoRaWAN example can be opened from the Arduino IDE via menu File / Examples / network_uplink

Our sketch is based on this example provided by ATIM.

Our modifications are enclosed between //bq and //qb comments :

// ---------------------------------------------------------------------
// Include
// ---------------------------------------------------------------------
#include <arm.h>

// ---------------------------------------------------------------------
// Define
// ---------------------------------------------------------------------
#define LED 13

// ---------------------------------------------------------------------
// Global variables
// ---------------------------------------------------------------------
//Instance of  the class Arm
Arm myArm;
//The message to send at Sigfox or Lora
uint8_t msg[] = "Hello world!";

// ---------------------------------------------------------------------
// Implemented functions
// ---------------------------------------------------------------------
//bq
#include <sds011.h>
#define ATIM_NOT_RESET 8
#define MY_EXTERNAL_LED 9
#define RX_FROM_SDS 10
#define TX_TO_SDS 11
SDS011 my_sds;
//qb</sds011.h>
void setup()
{
  //bq
  pinMode(ATIM_NOT_RESET,OUTPUT);
  digitalWrite(ATIM_NOT_RESET,HIGH);
  pinMode(MY_EXTERNAL_LED,OUTPUT);
  my_sds.begin(RX_FROM_SDS,TX_TO_SDS);
  //qb
    //Init Led for show error
    pinMode(LED, OUTPUT);
    digitalWrite(LED, LOW);
    
    //Init Arm and set LED to on if error
    if (myArm.Init(&Serial) != ARM_ERR_NONE)
        digitalWrite(LED, HIGH);
        
    //Get the Arm type
    armType_t armType;
    myArm.Info(&armType, 0, 0, 0, 0);
    
    //Set Lora mode or Sigfox mode
    if(armType == ARM_TYPE_N8_LW)
        myArm.SetMode(ARM_MODE_LORAWAN);
    else
        myArm.SetMode(ARM_MODE_SFX);
    
    //Set Sigfox mode in uplink.
    myArm.SfxEnableDownlink(false);
    
    //Set Lora mode in uplink.
    myArm.LwSetConfirmedFrame(/*bq 5 qb*/0);
    myArm.LwEnableOtaa(/*bq false */true/*qb*/);
    myArm.LwEnableRxWindows(true);
    myArm.LwEnableTxAdaptiveSpeed(true);
    myArm.LwEnableDutyCycle(false);
    myArm.LwEnableTxAdaptiveChannel(true);
    myArm.LwEnableRx2Adaptive(true);
    
    //Update the configuration into the arm.
    myArm.UpdateConfig();
}

//bq
void loop(){
  digitalWrite(MY_EXTERNAL_LED,HIGH); // LED ON
  my_sds.wakeup();
  delay(10000); // when fan is ON, wait 10" before acquiring
  float p25,p10;
  if (my_sds.read(&p25,&p10)==0) { // if SDS011 works well
    my_sds.sleep(); 
    int ip25=(p25*100+0.5);
    msg[0]=25; //0x19
    msg[1]=0x02;
    msg[2]=ip25/256;
    msg[3]=ip25%256;
    int ip10=(p10*100+0.5);
    msg[4]=10; //0x0A
    msg[5]=0x02;
    msg[6]=ip10/256;
    msg[7]=ip10%256;
    myArm.Send(msg, 8);
    digitalWrite(MY_EXTERNAL_LED,LOW); // LED OFF
    delay(50000);
    }
  else delay(1000); // else, try again 1" later
}
//qb
</arm.h>

Configure the Arduino board in the IDE

Compile and upload the sketch to the Arduino board

Luftdaten integration via PHP script

Configure HTTP integration on TTN, in order to push data to the following PHP script.

For this purpose, we have hosted this PHP script on OVH account.

NB : php-curl module is required by the script. Check that is module is enabled.

TTN2Luftdaten.php source code :


$json = file_get_contents('php://input');

$data = json_decode($json);
if(!isset($data)||!isset($data->payload_fields)){
    echo"Cayenne LPP decoder must be enabled on TTN account";
    return;
}
if(!isset($data->payload_fields->analog_in_10)||!isset($data->payload_fields->analog_in_25)){
    echo"Cayenne LPP should contain analog_in_10 and analog_in_25";
    return;
}
if(!isset($data->hardware_serial)){
    echo"EUI unknown";
    return;
}

$post=new stdClass();
$post->sensordatavalues[0]=(object)["value_type"=>"P1","value"=>$data->payload_fields->analog_in_10];
$post->sensordatavalues[1]=(object)["value_type"=>"P2","value"=>$data->payload_fields->analog_in_25];
//echo json_encode($post);

$ch=curl_init("http://api.sensor.community/v1/push-sensor-data/");
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    "X-Sensor: TTN-".$data->hardware_serial,
    "X-PIN: 1",
    "Content-Type: application/json"
));
curl_setopt($ch, CURLOPT_POSTFIELDS,json_encode($post));
$output=curl_exec($ch);
echo $output;
curl_close($ch);
?>

Create an account on https://meine.luftdaten.info

On Luftdaten account, register your device :

Sensor ID : DEV EUI of your ATIM device

Sensor Board : TTN

Location of the device is also required :

1 or 2 minutes later, data are available on Luftdaten :