Air Quality Monitoring Station (AQMS)

After a long time I decided to share my Personal Weather Station.
It is based on my PMS library (https://github.com/fu-hsi/PMS).

Installation

Configuration

Before uploading code, change configuration:

// Don't touch this ;-)
// #define FU_PROFILE

#ifdef FU_PROFILE
#include "Settings.h"
#else
// Debug (D4)
#define DBG Serial1

// Webservice
static const char* WS_UA = "AQMS/2.0";
static const char* WS_TOKEN = "YOUR TOKEN";
static const char* WS_URL = "YOUR SERVER SCRIPT";

// Wireless credentials
static const char* WL_SSID = "YOUR SSID";
static const char* WL_PASS = "YOUR PASSWORD";
static const uint8_t WL_CHANNEL = 0;

// OTA credentials
static const char* BE_USERNAME = "admin";
static const char* BE_PASSWORD = "admin";

// PMS configuration (INTERVAL & DELAY can't be equal!!!)
static const uint32_t PMS_READ_INTERVAL = 150000;
static const uint32_t PMS_READ_DELAY = 30000;

// Takes N samples and counts the average
static const uint8_t PMS_READ_SAMPLES = 2;
#endif // FU_PROFILE

Board settings

Board identification

If you have any problems, use flashInfo() function to identify board or CheckFlashConfig.ino (it's the same). This is very imporant for OTA update.

Circuit

I don't have necessary components for Fritzing, sorry...

Component	WeMos	Note
Debug output	D4
Battery monitor	A1	100k resistor in series (max. 4.2V).
PMS7003	TX => RX RX => TX VCC => 5V GND => GND	Disconnect before programming via a usb port!
SHT31-D	SDA => D1 SCL => D2 VCC => 3.3V GND => GND	For temperature and humidity (built-in heater).
BME280	SDA => D1 SCL => D2 VCC => 3.3V GND => GND	For pressure and temperature (temperature and humidity as backup).

Alternative sensors

I testet many sensors... The following list shows my ranking.

Rank	Sensor	Note
1	SHT31-D	Temperature, Humidity (built-in heater, Filter Caps are also available).
2	BMP280	Temperature, Pressure.
3	BMP180	Temperature, Pressure.
4	BME280	Temperature, Humidity, Pressure.
5	DHT22 (AM2302)	Temperature, Humidity.

Don't use BME280 for measuring temperature... I get readings overstated more than 2°C.
DHT22 is also a bad choice for measuring humidity.
Best combo for me is SHT31-D with BMP280, but BMP280 stopped working properly before publishing this project and I use BME280 now.

Dashboard

Components

Radiation shield TFA 98.1114.02
Wemos D1 ESP-WROOM-02
Plantower PMS7003
SHT31-D
BME280

Measured values

Pollution
Temperature and humidity
Pressure
Battery voltage

Additional features

OTA update over Wi-Fi
Sending data to the server
Mobility (Lithium-ion battery)
Battery monitor
File logging

Working time

Up to 8 hours with listed conditions:

Default configuration
Li-Ion ~1500mAh
Temperature ~3°C

Photos

Rev. 1

In surface mounted S-BOX 116B IP65 (old hardware).

Rev. 2

Merged with my previous meteorological station in the radiation shield.

Mounted on the balcony and powered through a thin cable connected to a PC USB.
USB socket in WeMos was removed (accidentally ;-).

Couple pictures from inside.

Database

Table structure

CREATE TABLE `weather_pms` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `dt` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `pm1` smallint(6) DEFAULT NULL,
  `pm25` smallint(6) DEFAULT NULL,
  `pm10` smallint(6) DEFAULT NULL,
  `rv` smallint(6) DEFAULT NULL,
  `v` float(4,2) DEFAULT NULL,
  `temperature` float(4,2) DEFAULT NULL,
  `humidity` float(4,2) DEFAULT NULL,
  `pressure` float(6,2) DEFAULT NULL,
  `bm280_temp` float(4,2) DEFAULT NULL,
  `bm280_hum` float(4,2) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=146810 DEFAULT CHARSET=utf8;

Sample data

    id                   dt     pm1    pm25    pm10      rv       v  temperature  humidity  pressure  bm280_temp  bm280_hum  
------  -------------------  ------  ------  ------  ------  ------  -----------  --------  --------  ----------  -----------
146810  2018-12-17 22:00:57      22      40      52    1024    4.20        -0.79     95.15   1008.28       -0.26        81.28
146809  2018-12-17 21:57:57      26      44      66    1024    4.20        -0.72     94.94   1008.31       -0.17        80.95
146808  2018-12-17 21:54:57      22      36      40    1024    4.20        -0.76     94.93   1008.31       -0.28        81.25
146807  2018-12-17 21:51:57      18      34      43    1024    4.20        -0.79     95.20   1008.26       -0.17        81.19
146806  2018-12-17 21:48:57      16      34      50    1024    4.20        -0.92     95.49   1008.25       -0.35        81.66
146805  2018-12-17 21:45:57      22      40      52    1024    4.20        -0.93     95.45   1008.27       -0.41        81.77

Server

I have PHP script on my VPS server where I receive POST data. These data are then sent (after some calculations) to:

SQL Database
https://thingspeak.com/
https://www.wunderground.com/

What calculations do I mean? For example:

Reduced pressure
Heat Index
Dev Point

I also reject the results below a certain voltage.

For simplicity, I share only a basic ws.php script. Rest is in your gesture.

<?php
error_reporting(0);
ini_set('display_errors', 0);
date_default_timezone_set('Europe/Warsaw');

// define('FU_PROFILE', true);

if (defined('FU_PROFILE')) {
    require_once 'config.php';
} else {
    define('WS_TOKEN', 'YOUR TOKEN');

    define('DB_HOST', 'YOUR DB HOST');
    define('DB_USER', 'YOUR DB USER');
    define('DB_PASS', 'YOUR DB PASS');
    define('DB_NAME', 'YOUR DB NAME');
}

class DB
{
    private static $db = null;
    private function __construct()
    {}
    public static function getConnection()
    {
        if (self::$db == null) {
            $dsn = sprintf('mysql:dbname=%s;host=%s', DB_NAME, DB_HOST);
            $options = array(
                PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8",
                PDO::ATTR_ERRMODE => PDO::ERRMODE_SILENT,
                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
            );
            self::$db = new PDO($dsn, DB_USER, DB_PASS, $options);
        }
        return self::$db;
    }
}

if (!empty($_SERVER['HTTP_X_TOKEN']) && $_SERVER['HTTP_X_TOKEN'] == WS_TOKEN) {
 
  // Allowed fields
  $whiteList = [
    'pm1', 'pm25', 'pm10',
    'rv', 'v',
    'temperature', 'humidity', 'pressure', 'bm280_temp', 'bm280_hum'
  ];  

  // Clear array
  $whiteList = array_fill_keys($whiteList, NULL);

  // Prepare array
  $storeData = [];
  $storeData = array_merge($storeData, $whiteList, array_intersect_key($_POST, $whiteList));

  try {   
    $db = DB::getConnection();
    $stm = $db->prepare('INSERT INTO weather_pms SET dt = NOW(), ' . implode(',', array_map(function ($key) {
      return $key . ' = :' . $key;
    }, array_keys($storeData))));
    $stm->execute($storeData);   
  } catch(PDOException $e) {
    exit('DB error');
  }

}
?>

Typical flow

Todo

Add a GPS module for use in the field (https://github.com/fu-hsi/FuGPS).
UTC time from GPS is an extra bonus for work in offline mode.

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README.md

README.md

Air Quality Monitoring Station (AQMS)

Installation

Dashboard

Components

Measured values

Additional features

Working time

Photos

Rev. 1

Rev. 2

Database

Server

Typical flow

Todo

Files

README.md

Latest commit

History

README.md

File metadata and controls

Air Quality Monitoring Station (AQMS)

Installation

Dashboard

Components

Measured values

Additional features

Working time

Photos

Rev. 1

Rev. 2

Database

Server

Typical flow

Todo