Mobile Fine Dust (PM10 & PM2.5) and NO2 Meter

This device measures fine dust and NO2 concentration in the air while on the move and adds GPS coordinates to each measurement location.

Oct 13, 2018

30154 views

45 respects

Components and supplies

1

Resistor 2.21k ohm

1

Arduino Nano R3

6

7-segment single digit

5

Resistor 1k ohm

1

Capacitor 100 nF

1

74LS138 3-to-8 line decoder TTL IC

1

Dual Pole Dual Throw (DPDT) Switch

1

555 Timers

1

Open Smart GPS-module

1

Resistor 33k ohm

2

General Purpose Transistor NPN

1

SDcard reader VMA304

1

NO2-sensor CJMCU-4541

1

General Purpose Transistor PNP

1

Single Turn Potentiometer- 100k ohms

3

Resistor 330 ohm

1

Capacitor 100 µF

2

3 mm LED: Red

1

DHT22 Temperature Sensor

1

Resistor 560 ohm

1

Fine dust sensor SDS011

6

74HC4511 BCD to Seven-Segment Decoder / Driver / Latch

Apps and platforms

1

Google Maps

Project description

Code

Mobile fine dust and NO2 meter

arduino

This is the code for the mobile fine dust meter with the optional display and NO2 meter, but this code also works for the basic version without display and the NO2 meter. Mandatory modules are the SDS011 fine dust sensor, the DHT22 sensor for measuring humidity and temperature and the GPS-module, because these modules transmit their measurements over a serial interface and for each of these sensors a wait-loop is traversed to capture new serial data. Also mandatory is the SDcard interface (SPI) which takes care of the logging of the gathered data on a SDcard. Further, this code features the following functions: 1. Creation of a new logfile each time the meter is powered on. 2. Calculation of a hash code when writing a new data record to the logfile. 3. Creation of a digital signature using the hash code at power shutdown or too low supply voltage. 4. Monitoring of the supply voltage and giving a low battery warning on the display 5. Software controlled power down to finish ongoing write cycle to the SDcard and writing the signature. 6. Round-robin rotation through 4 display modes by toggling the DPDT power switch. 7. Showing 6 different error codes on the display: 001 SDcard initialization failed 002 No FAT partition found 003 Initialization file access failed 004 Low battery voltage 005 GPS signal unreliable 006 Cannot open the logfile

Downloadable files

Schematics of the main interconnection board

This board interconnects all components: Arduino Nano, OpenSmart GPS-module and SDcard reader are plugged directly onto the board. The sensors SDS011, DHT22 and GJMCU-4541 are connected via cables as well as the optional display board and the earphone connector for the external warning device. The board houses also the soft power off electronics, a timer to provide a 30 seconds preheating of the NO2-sensor and a LED indicating write cycles to the SDcard. Battery power and DPDT-switch are also connected to the main board.

Schematics of the main interconnection board

Schematics of the main interconnection board

This board interconnects all components: Arduino Nano, OpenSmart GPS-module and SDcard reader are plugged directly onto the board. The sensors SDS011, DHT22 and GJMCU-4541 are connected via cables as well as the optional display board and the earphone connector for the external warning device. The board houses also the soft power off electronics, a timer to provide a 30 seconds preheating of the NO2-sensor and a LED indicating write cycles to the SDcard. Battery power and DPDT-switch are also connected to the main board.

Schematics of the main interconnection board

Display Board

This is the optional display board, which comprises 2x3 7-segment digits to show the measurement results of the 5 sensor values in real time.

Display Board

Display Board

This is the optional display board, which comprises 2x3 7-segment digits to show the measurement results of the 5 sensor values in real time.

Display Board

Documentation

Mechanical drawing of main interconnection PCB

A printed circuit board has been developed on which all components can be soldered or connected by means of flat cables. The Arduino Nano microcontroller, SDcard, GPS-module and electronics to ensure soft power down are soldered onto this board. DHT-, NO2- and PM-sensors are connected to this board via flat cables.

Mechanical drawing of main interconnection PCB

Transparant housing for mobile finedust meter

This is the housing in which all components will fit perfectly, including the display board and battery.

Transparant housing for mobile finedust meter

Mechanical drawing of main interconnection PCB

A printed circuit board has been developed on which all components can be soldered or connected by means of flat cables. The Arduino Nano microcontroller, SDcard, GPS-module and electronics to ensure soft power down are soldered onto this board. DHT-, NO2- and PM-sensors are connected to this board via flat cables.

Mechanical drawing of main interconnection PCB

Transparant housing for mobile finedust meter

This is the housing in which all components will fit perfectly, including the display board and battery.

Transparant housing for mobile finedust meter

Comments

Only logged in users can leave comments

Telina

0 Followers

0 Projects

Table of contents

Intro

45

0