🔘The SpacerLabs domestic 'Air Quality Monitor' ( AQM ) 🏭 with multi-sensor support posted on 15.03.2023, ( updated 29.02.2024 ) is based on the Cubic PM1006 infra-red LED particle sensor module. Another type of particle sensor is the 🪴 Plantower 🗼PMS5003. It uses a laser source, is capable of detecting particles down to ⌀0.3 microns in size, and measures some additional values compared to the PM1006 as well as being approximately twice as accurate. One has been obtained as an individual item, ( not part of an AQM product, filtration or ventilation equipment etc ), and is being tried out.
The measurements made by the PMS5003 are sent periodically ⏲ as 32 bytes
of data over a UART serial interface at a data rate of 9600 bits/sec. A
UART to USB protocol converter dongle provides a virtual COM port on a
computer allowing the data to be displayed on a pc if there is a usb cable connecting 🔗both and a serial terminal program is running.
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| Left - PMS5003, Right - UART to USB dongle |
We wrote a serial terminal application specifically for the PMS5003, called 'PMS5003_Serial', with only basic functionality in order to demonstrate the operation of the PMS5003, ( image below ).
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| PMS5003_Serial software receiving & displaying data |
The received raw serial data are displayed in hexadecimal and decimal, then parsed in software to extract the bytes of interest containing data relating to particulate matter🦠 mass concentration ( ug/m^3 ) and particle number per deci-litre, ppdl, ( 0.1 litre ) of air 🜁 , sorted according to size in microns. The AQI ( range 0-500 ) and air quality level are also given.
This project might be developed further by providing embedded control, a touch sensitive colour display, Bluetooth, App for a mobile device and a 3-D printed case.
UART = Universal Asynchronous Receiver Transmitter.
AQI = Air Quality Index
