PureAware V1.025 — Installation Manual

1. Product Overview

The PureAware Air Quality Sensor (model PureAQS66, firmware V1.025) is a professional-grade ESP32-based environmental monitoring device designed for building automation, HVAC, and indoor air quality management.

It integrates the Sensirion SEN66 multi-parameter sensor and the MS5637 barometric pressure sensor, providing continuous measurement of 11 environmental parameters:

Parameter	Range	Unit
CO2	0–40,000	ppm
PM1.0	0–1,000	µg/m³
PM2.5	0–1,000	µg/m³
PM4.0	0–1,000	µg/m³
PM10	0–1,000	µg/m³
VOC Index	1–500	— (unitless)
NOx Index	1–500	— (unitless)
TVOC (WELL)	derived	µg/m³
Temperature	−40 to +125	°C
Humidity	0–100	%RH
Barometric Pressure	300–1,200	hPa

Manufacturer: MICRO-ELEMENTS S.R.L.

Serial Number Format: AQS2608-[MAC_ADDRESS]

2. Package Contents

PureAware sensor unit (PureAQS66)
USB-C power cable
Mounting bracket and screws
Nextion TFT display (optional, model-dependent)
Quick Start card

3. Safety & Precautions

WARNING: Do not expose the device to water, excessive dust, or corrosive gases. The SEN66 sensor contains sensitive optical and electrochemical components.

Operating temperature: −10°C to +50°C
Operating humidity: 0–95% RH (non-condensing)
Supply voltage: 5V DC via USB-C
Do not obstruct the air intake vents
Install in a location with representative air circulation
Avoid direct sunlight on the sensor
Keep away from strong electromagnetic interference sources

4. Technical Specifications

Parameter	Value
Model	PureAQS66
Hardware Revision	AQS-PureAware-R1.2
Microcontroller	ESP32 (Dual-core Xtensa, 240 MHz)
Primary Sensor	Sensirion SEN66 (CO2, PM, VOC, NOx, T, RH)
Pressure Sensor	TE Connectivity MS5637 (I2C @ 0x76)
Connectivity	WiFi 802.11 b/g/n (2.4 GHz)
Protocols	BACnet/IP, Modbus TCP, MQTT, Zabbix, HTTP/REST
BACnet Port	47808 (UDP)
Modbus Port	502 (TCP, async, up to 3 clients)
Web Ports	80, 8080, 8081, 8082
Power Supply	5V DC, ~300 mA typical
Filesystem	LittleFS (OTA + logs + config)
Data Logging	288-entry RAM buffer + 7-day CSV rotation
Watchdog Timer	50 seconds
Discovery	mDNS + SSDP
Languages	EN, RO, HU, NO, JA
Authentication	HTTP Basic Auth (admin/pureaware)

5. Hardware Installation

5.1 Mounting Location

Mount the device at a height of 1.2–1.8 meters (breathing zone) on a wall, away from:

Direct heat sources (radiators, ovens)
Air conditioning vents and ducts
Windows and doors (drafts)
Direct sunlight
Chemical storage areas

5.2 Sensor Connections

All sensors are pre-wired on the PCB. If performing custom wiring:

SEN66 → I2C Bus 1 (GPIO 26/SDA, GPIO 25/SCL) at 100 kHz
MS5637 → I2C Bus 2 (GPIO 33/SDA, GPIO 32/SCL) at 100 kHz, address 0x76

5.3 RS-485 Connection (Optional)

For RS-485 communication:

Serial1: RX = GPIO 16, TX = GPIO 17
Direction control: GPIO 2 (HIGH = transmit)
Baud rate: 19200 bps, 8N1

5.4 Nextion Display (Optional)

Connect to Serial2: RX = GPIO 14, TX = GPIO 27 at 115200 baud.

6. GPIO Pinout Reference

GPIO	Function	Direction	Notes
13	NeoPixel LED	Output	WS2812B, 1 pixel, 800 kHz
22	Config Button	Input	Internal pull-up (active LOW)
23	Run Button	Input	Internal pull-up (active LOW)
12	Status LED	Output	General purpose indicator
2	RS-485 Control	Output	HIGH = transmit enable
16	Serial1 RX	Input	RS-485 receive (19200 baud)
17	Serial1 TX	Output	RS-485 transmit
14	Serial2 RX	Input	Nextion display (115200 baud)
27	Serial2 TX	Output	Nextion display
26	I2C Bus 1 SDA	Bidir	SEN66 sensor (100 kHz)
25	I2C Bus 1 SCL	Output	SEN66 sensor (100 kHz)
33	I2C Bus 2 SDA	Bidir	MS5637 @ 0x76 (100 kHz)
32	I2C Bus 2 SCL	Output	MS5637 @ 0x76 (100 kHz)

7. Powering the Device

Connect a 5V DC power source via the USB-C port. Typical draw is ~300 mA.

Important: Allow 30–60 seconds after power-on for sensor stabilization. CO2 accuracy improves significantly after 3 minutes of continuous operation. VOC and NOx indices require up to 12 hours for full algorithm conditioning.

8. First Boot & AP Mode

On first power-up (or after pressing the CONFIG button on the back of the device), the device starts in Access Point (AP) mode:

The device creates a WiFi network named "PureAware_XXXXXX" (where XXXXXX is a unique suffix derived from the MAC address)
Connect using password: 123456789
A captive portal should open automatically. If not, navigate to http://192.168.1.25:8080
Configure your WiFi credentials, hostname, and desired protocol settings
Press the RUN button on the back of the device — the device saves settings, reboots, and connects to your WiFi network in STA mode

Note: In AP mode, the device IP is always 192.168.1.25. A DNS captive portal redirects all browser requests to the configuration page.

Hostname: The device advertises itself via mDNS as <hostname>-<mac_suffix>.local (e.g., pureaware-8a0de8.local). Use this to access the device without knowing its IP.

9. WiFi Configuration

Three operating modes:

Mode	Description	Use Case
AP	Creates "PureAware" network	Setup, standalone
STA	Connects to existing WiFi	Normal operation
OFFLINE	WiFi radio disabled	Air-gapped, power saving

Mode switching via serial commands on Serial2:

01 01 01 FF FF FF — AP mode
02 02 02 FF FF FF — STA mode
03 03 03 FF FF FF — OFFLINE mode

Discovery protocols active in STA mode: mDNS, SSDP.

10. Static IP Configuration

For fixed-IP deployments (common in BMS/HVAC), configure via the web interface:

Parameter	Default	Description
Static IP Enable	Disabled	Toggle static IP
IP Address	empty	Device IP (e.g., 192.168.1.100)
Gateway	empty	Router IP (e.g., 192.168.1.1)
Subnet Mask	255.255.255.0	Network mask
DNS Server	8.8.8.8	DNS resolver

11. Web Interface

Port	Function	Authentication
80	Status Dashboard (real-time readings & charts)	None (public)
8080	Configuration Panel	HTTP Basic Auth `admin / pureaware`
8081	OTA Firmware Upload	None
8082	Nextion Display Upload	None

The status dashboard features a responsive dark-theme design with real-time sensor readings, 24-hour history charts, and multilingual UI support (5 languages).

12. MQTT Setup

V1.025 uses a fully asynchronous MQTT client (non-blocking, based on AsyncClient). The device publishes sensor data as JSON to an MQTT broker at a configurable interval.

12.1 Configuration Parameters

Parameter	Default	Description
MQTT Enable	Disabled	Toggle MQTT publishing
Server	`broker.emqx.io`	Broker hostname or IP
Port	`1883`	Broker TCP port
Username	empty	Auth username (optional)
Password	empty	Auth password (optional)
Topic	hostname	Base publish topic
Sensor Name	empty	Friendly name included in JSON payload
Interval	60 seconds	Publish interval (minimum 10 seconds)

12.2 Topic Structure

The device publishes to a topic constructed from the configured base topic, the device MAC address suffix, and a /data suffix:

{topic}/{mac6}/data

For example, if the base topic is PureAware_Office and the device MAC suffix is 8a0de8:

PureAware_Office/8a0de8/data

Note: The mac6 is the last 6 hex digits of the ESP32 MAC address. This ensures each device has a unique publish topic even when sharing the same base topic.

12.3 Public Broker (Quick Start)

For quick testing, use the free public EMQX broker:

Parameter	Value
Server	`broker.emqx.io`
Port	`1883` (TCP) / `8083` (WebSocket)
WebSocket URL	`ws://broker.emqx.io:8083/mqtt`
Username	`emqx`
Password	`public`

Important: Public brokers are suitable for testing only. For production deployments, use a private MQTT broker (e.g., Mosquitto, EMQX, HiveMQ) with TLS encryption and authentication.

12.4 Remote Monitoring

PureAware provides companion monitoring applications that connect to the same MQTT broker via WebSocket and display live sensor data from all discovered devices:

Browser — Open monitor_remote.html in any web browser (included in the product package)
Windows — Install PureAware_Monitor_Setup.exe (standalone desktop application)
Android — Install PureAware_Monitor_V1.apk on your Android device

All three applications auto-discover devices by subscribing to {topic}/# and display live sensor cards with AQI badges, color-coded thresholds, and timeout detection.

In the monitoring app settings, configure:

Setting	Value
Broker	`ws://broker.emqx.io:8083/mqtt` (or your broker's WebSocket URL)
Topic	Same base topic configured on the device
User / Pass	Broker credentials (if required)

13. Zabbix Integration

Asynchronous Zabbix Sender protocol with a dedicated timer.

Parameter	Default
Zabbix Server	`monitor.microelemente.ro`
Zabbix Port	`55051`
Hostname	`PureAware_Default`
Interval	60 seconds

14. BACnet/IP Setup

The device implements a minimal BACnet/IP server per ASHRAE 135-2020, Annex J, on UDP port 47808.

14.1 Enabling BACnet

Enable via the configuration web page. The Device Instance ID is derived from the MAC address by default, or can be set manually (range: 1–4,194,302).

14.2 Exposed Objects

Object	Instance	Name	Unit
Device	auto (MAC-derived)	hostname	—
AI 0	0	CO2	ppm
AI 1	1	PM1.0	µg/m³
AI 2	2	PM2.5	µg/m³
AI 3	3	PM4.0	µg/m³
AI 4	4	PM10	µg/m³
AI 5	5	VOC Index	No units
AI 6	6	NOx Index	No units
AI 7	7	TVOC	ppb
AI 8	8	Temperature	°C
AI 9	9	Humidity	%RH
AI 10	10	Pressure	hPa

14.3 Supported Services

Who-Is / I-Am — Device discovery (unicast + broadcast)
ReadProperty — Read any supported property
ReadPropertyMultiple — Batch property reads
WriteProperty — Write Present_Value (Binary Output only)

Vendor: MICRO-ELEMENTS S.R.L.

15. Modbus TCP

Asynchronous Modbus TCP server on port 502, supporting up to 3 simultaneous clients with a 60-second idle timeout.

15.1 Input Registers (FC 04)

Register	Parameter	Unit	Notes
0	Device Type	—	Fixed: 1
1	VOC Index	—	1–500
2	NOx Index	—	1–500
3	PM1.0	µg/m³	Integer
4	PM2.5	µg/m³	Integer
5	PM4.0	µg/m³	Integer
6	PM10	µg/m³	Integer
7	Temperature	°C × 10	e.g. 235 = 23.5°C
8	Humidity	%RH × 10	e.g. 654 = 65.4%
9	CO2	ppm	Integer
10	TVOC (WELL)	µg/m³	Integer
11	Pressure	hPa × 10	e.g. 10132 = 1013.2 hPa

15.2 Supported Function Codes

FC 01 — Read Coils
FC 02 — Read Discrete Inputs
FC 03 — Read Holding Registers
FC 04 — Read Input Registers
FC 05 — Write Single Coil
FC 06 — Write Single Register
FC 0F — Write Multiple Coils
FC 10 — Write Multiple Registers

16. Alarm System & Email Alerts

The device supports 3 independent alarms with hysteresis, email notifications, and a state machine.

16.1 Alarm Configuration

Parameter	Description
Enabled	Enable/disable this alarm
Parameter	Monitored value: co2, pm25, pm1, pm4, pm10, voc, nox, tvocw, temp, hum, press
Trigger Threshold	Value at which the alarm triggers
Hysteresis	Deadband for rearming (prevents oscillation)
Direction	1 = above threshold, 0 = below threshold

16.2 Alarm State Machine

  OK ──► Armed ──► Triggered ──► Rearmed ──► OK
         (value enters       (threshold      (value returns
          deadband)           crossed)        below hyst)

16.3 Email Configuration (SMTP)

Parameter	Default	Description
Email Enable	Disabled	Global email toggle
SMTP Server	empty	e.g., smtp.gmail.com
SMTP Port	587	587 (STARTTLS) or 465 (SSL)
TLS	Enabled	STARTTLS or implicit SSL
Username	empty	SMTP auth user
Password	empty	SMTP auth password
From	empty	Sender email address
To	empty	Recipient email address

Note: Emails are queued in RAM when WiFi is down (2 slots per alarm: trigger + rearming events). They are sent automatically when WiFi reconnects (5-second delay for DHCP/DNS stabilization).

17. WiFi Sleep Hours

Schedule automatic WiFi disconnection during specific hours to save power or comply with EMF policies:

Parameter	Default	Description
Enable	Disabled	Toggle sleep schedule
Start Hour	22:00	WiFi off time
End Hour	06:00	WiFi on time

Note: Supports midnight-crossing intervals (e.g., 22:00–06:00). Data logging continues during WiFi sleep — only network connectivity is disabled.

18. Data Logging

The device maintains two layers of data logging:

18.1 RAM Buffer

288 entries × 5 minutes = 24 hours of data in RAM
Accessible via the web dashboard for real-time charting
Circular buffer — oldest entries overwritten

18.2 File-based Logging (LittleFS)

7-day rotation: day0.csv through day6.csv
Automatic midnight rotation
Hourly writes to flash filesystem
CSV format with timestamps (NTP-synced when available)

18.3 NTP Time Synchronization

The device syncs time via NTP when WiFi is available. Three fallback levels ensure timestamps are always present:

NTP — Full precision when synced
Saved base — Restored from LittleFS after reboot (error < 1 hour)
Fallback — Jan 1, 2026 + uptime (usable even without network)

19. OTA Firmware Updates

19.1 Manual Upload

Navigate to http://<ip>:8081
Select the .bin firmware file
Click Upload and wait for completion
The device reboots automatically

19.2 Automatic OTA (STA mode only)

Every 24 hours, the device checks https://update.microelemente.ro/firmware.bin for new firmware. Downloads are staged to LittleFS before flashing, protecting against incomplete downloads.

WARNING: Do not power off the device during firmware update!

20. Nextion Display

The optional Nextion HMI display shows real-time sensor data. Connect via Serial2 (GPIO 14/27 at 115200 baud).

Upload display firmware (pureaware_v3.tft) via the web interface on port 8082.

21. LED Status Indicators

Color/Pattern	Meaning
Green (solid)	Normal operation, WiFi connected
Blue (solid)	AP mode active
Red (solid)	Error / sensor fault
Yellow (blinking)	WiFi connecting
Off	LED disabled or OFFLINE mode

22. Button Functions

The device has two physical buttons located on the back (spare side) of the module:

Button	GPIO	Function	Action
CONFIG	22	Enter configuration mode	Press → saves AP mode → reboots → starts as Access Point (IP: 192.168.1.25)
RUN	23	Enter run mode	Press → saves STA mode → reboots → connects to configured WiFi network

Workflow: Press CONFIG to enter AP mode for configuration. After setup, press RUN to switch to normal operation (STA mode). Both actions trigger an automatic reboot.

23. Language Support

The web interface and email notifications support 5 languages:

EN — English
RO — Romanian (Românã)
HU — Hungarian (Magyar)
NO — Norwegian (Norsk)
JA — Japanese (日本語)

Set the language via the configuration web page. Default: en.

24. Troubleshooting

Symptom	Possible Cause	Solution
No WiFi network visible	Not in AP mode	Press Config button
Cannot reach web UI	Wrong port or IP	Use `http://<ip>` on port 80 or 8080
All sensor values are 0	SEN66 not initialized	Wait 60s; check I2C Bus 1 wiring
Pressure reads 0	MS5637 disconnected	Verify I2C Bus 2 (GPIO 33/32)
BACnet not responding	Not enabled or no WiFi	Enable in config; verify port 47808 not blocked
Modbus timeout	Max clients reached	Reduce connections (max 3)
Email not sending	SMTP credentials wrong	Check server, port, TLS, credentials
Device reboots randomly	Watchdog timeout (50s)	Check power supply; verify I2C not locked
Log files missing	LittleFS not mounted	Reflash with correct partition scheme
mDNS not resolving	Router blocks mDNS	Use IP address directly or enable SSDP

25. Factory Reset

To restore factory defaults:

Use the configuration page "Reset to Defaults" option

Or erase NVS via serial programmer:

esptool.py --port COMx erase_region 0x9000 0x5000

Power cycle — device boots in AP mode with default settings

Note: Factory reset clears WiFi credentials, MQTT/Zabbix/BACnet settings, alarm configurations, and email settings. Log files on LittleFS are preserved.