Showing posts with label UART. Show all posts
Showing posts with label UART. Show all posts

08 April 2024

PMS5003 Digital Particle Concentration Sensor

🔘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. 
Left - PMS5003, Right - UART to USB dongle
We wrote a serial terminal application specifically for the PMS5003, called 'PMS5003_Serial' , in order to demonstrate the operation of the PMS5003, ( image below ).
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 particles 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
 
 

09 January 2022

USB to UART Converter

Some devices, e.g., ESP8266-01 wifi modules, GNSS receiver modules, Particulate Matter sensors and others have a 'start-stop signalling' RS232 type of serial interface for exchanging data. A USB to UART ( Universal Asynchronous Receiver Transmitter ) converter is required in order to display the data using a serial terminal program on a pc for example. Other uses include: alternative if no legacy COM port, provides a virtual COM port, provides usb connectivity, for retreiving raw data for display and parsing, connect with devices having a uart interface, connect with usb to a micro-controller uart peripheral. It's an extremely useful item.
USB-UART converter connected to ESP8266-01 wifi module
TX and RX data shown in a serial terminal application