Seven in one air quality detector

1、 Product Description

The seven in one air quality detector is a cost-effective digital signal output sensor product that uses RS485 output mode and integrates CO2, formaldehyde TVOC、 Integrated laser dust PM2.5/PM10 particle, temperature, and humidity sensors. It can perform real-time comprehensive detection of the environment, has good stability, and is very convenient for customers to use.

2、 Application Fields

Hotel room air quality monitoring

● Fresh air exchange system

Air purifier, air conditioner

Air quality monitoring equipment

Kitchen and bathroom ventilation control system

● Smart home devices

3、 Product Features

Simultaneously output CO2, formaldehyde TVOC、PM2.5、PM10、 Seven sets of temperature and humidity data

High sensitivity and stable data

RS485 output

Temperature resolution 0.1 ℃, humidity resolution 0.1% RH

Up to 0.5 seconds to output seven sets of sensor monitoring data through RS485 signal output

4、 Range accuracy

5、 Technical parameters

6、 Interface definition

6、 Appearance dimension diagram

7、 Precautions

Preheat for at least 2 minutes before initial power on use

Do not expose this module to high concentrations of organic gases and corrosive gases for extended periods of time

Do not install the module in a strongly convective gas environment for use

To avoid contamination by large dust particles or even flocculent substances such as ground dust, floating debris, etc., which may cause fan entanglement and stall, build

Appropriate pre filtering treatment should be adopted for the use of equipment

Users should not disassemble the sensor, including the metal shielding shell, to prevent irreversible damage

This sensor is suitable for ordinary indoor environments

8、 RS485 communication protocol

1. Overview of RS485 Communication Protocol

The communication protocol provides a detailed description of the input and output commands, information, and data of the seven in one air quality detector for third-party use and development.

Physical interface:

Connect the main communication port of the upper computer using a standard serial RS-485 communication port.

The information transmission method is asynchronous, with a start bit of 1, a data bit of 8, a stop bit of 1, and no checksum. The default data transmission rate is 9600b/s

2. Communication protocol details

2.1 Communication Method

1) All loop communication should follow the master/slave mode. In this way, information and data are transmitted between a single master station and a slave station (monitoring device).

2) Supports broadcast mode.

3) Under no circumstances can communication start from a slave station.

4) If the master station or any slave station receives a package containing an unknown command, the package will be ignored and the receiving station will not respond.

2.2 Return data frame structure description

Each data frame is composed of the following: (RTU mode)

address

function code

data quantity

Data 1

...

Data n

CRC 16 bit checksum

3. Transmission format

1) Host sends read address command:

Return address from machine:

Example: Sent: 00 03 01 00 00 01 84 27

Response: 00 03 02 00 addr CRCL CRCH If addr=2, the sensor address read is 2

2) Host sends read data command:

At present, it only supports reading all data, starting from address 0002 and reading 7 data values. There are only 7 sensor data, corresponding to 7 sensor addresses. The high bit of the starting address of the data is always 0, and the high bit of the returned data is always 0

Internal message information

The starting address can only use addresses from the above list, otherwise there will be no response If the number of data exceeds, there will be no response. For example, if the starting address is 0X000C, the number of data that can be returned can only be 1 or 2. If 3 data are to be returned, there will be no response Similarly, for address 0X000E, the number of returned data can only be 1. If the number of returned data is 0, there will be no response.

Return value from slave sensor:

Byte length only refers to the length of data.

Example: Host sends 01 03 00 02 00 07 CRCL CRCH

Response: 01 03 0E 02 26 00 26 00 34 00 0E 00 11 01 1C 02 5D CRCL CRCH