Ten in one environmental sensor - temperature and humidity, formaldehyde TVOC、 Carbon dioxide PM2.5、 Noise and illuminance

Product Introduction:The X-SSG-A1101-RS485 ten in one environmental and air quality sensor adopts a high-speed processor and integrates CO2, formaldehyde TVOC, Laser dust PM2.5, PM10, PM1.0 particulate matter, temperature, humidity, air pressure, light intensity, and noise detection are integrated, and environmental quality data detection and reporting are achieved through RS485 bus communication. Adopting a rotating buckle method for ceiling installation, the operation is simple.

sensor data	Measurement Resolution	measurement range	measurement accuracy
Carbon dioxide eCO2	1ppm	400 ~ 60,000ppm	±30ppm
TVOC	1ug/m3	0 ~ 60,000ug/m³	± 50ug/m3
Formaldehyde CH2O	1ug/m3	0~1000ug/m ³	± 25%
PM2.5	1ug/m3	0~1000ug/m ³	± 10%
PM10	1ug/m3	0~1000ug/m ³	±10%
PM1.0	1ug/m3	0 ~ 1,000ug/m³	±10%
temperature	0.01℃	-40 ~ 85℃	±0.2℃
Humidity	0.01%	0 ~ 100%	±1%RH
air pressure	1Pa	30,000 ~ 110,000Pa	±12Pa
illuminance	1Lux	0 ~ 60,000Lux	±5%
Noise	1dB	30 ~ 90dB	±3dB

Attention: The CH2O value output by the module is the equivalent value of TVOC. Customers should pay attention when purchasing and using it.

Working voltage:

DC5V±0.2V @150mA

Work environment:

Working temperature -10~60 ℃, working humidity: 5~95% RH (non condensing)

Communication method:

Modbus RTU 485 interface

Preheating time:

Less than 3 minutes,In theory, semiconductor VOC sensors are more stable as the power on time increases

Service life:

3 years (in the air)

Appearance dimension diagram:

I, standard 4-wire interface

II, 2-wire+USB power supply interface

As shown in the above figure,This product comes with two physical interfaces: "standard 4-wire interface" and "2-wire+USB power supply". Please indicate according to actual needs when purchasing.

This product defaults to 5V DC power supply. If you need a special voltage (6-36V), you can contact us to customize.

wiring definition

1) "Standard 4-wire" interface type:

Serial number	Name	Remarks
RS485	Yellow	RS485 | A
RS485 | B	Green	RS485 | B
DC+	Red	Default 5V DC power supply, special voltage needs to be customized
GND	Black	Grounding wire

"2-wire+USB power supply" Interface type:

2)

Serial Number	Name	Remark
A	Red (A)	RS485_A
B	Black (B)	RS485_B
U	Micro USB	DC 5V power supply

Attention: The colors in the table above are for general instructions. Please refer to the label on the product for specific wiring.

IV. RS485 Communication Protocol

Communication Parameters

ModBus RTUParameters:

9600/8/N/1

Factory default address:0x01

Return data time: less than 100ms

Communication protocol

1)Read address command

Direction: User application ->Sensor module; Response required: Yes

Request message format:

Byte number	Data	Description
0	0xFE	Broadcast Address
1	0x11	Report Slave Address Function Code
2	0x00	Fixed
3	0x00	Fixed
4	0x00	Fixed
5	0x01	Fixed
6 7	CRC-L CRC-H	CRC Check

Response Message Format:

Byte Number	Data	Description
0	0x01	Slave Address
1	0x11	Report Slave Address Function Code
2	0x02	Byte Count
3	version	Firmware Version
4	address	Current Address
5 6	CRC-L CRC-H	CRC Check

Example: Send Command:FE 11 00 00 01 28 06

Return Data: 01 11 02 12 01 70 5C

Explanation: 0x12 in the returned data represents version number V1.2, 0x01 represents device address 01

2)Modify Address Command. The default factory address for the module is0x01, and the address range can be changed to:1~247

Direction: User Application ->Sensor Module; Response required: Yes

Request message format:

Byte number	Data	Description
0	address	Current address
1	0x06	Function code
2	0x00	Fixed
3	0x00	Fixed
4	0x00	Reserved
5	new address	New Address
6 7	CRC-L CRC-H	CRC Check

Response Message Format:

Byte Number	Data	Description
0	address	Address before modification
1	0x06	Function code
2	0x00	Fixed
3	0x00	Fixed
4	0x00	Reserved
5	new address	Modified address
6 7	CRC-L CRC-H	CRC Check

For example: The current address is 0x01, and the preset address is 0x02

Send Command:01 06 00 00 02 08 0B

Return Data: 01 06 00 00 02 08 0B

Change the current address from 0x02 to 0x01

Send Command:02 06 00 00 01 48 39

Return Data: 02 06 00 00 00 00 01 48 39

3)Read Data Command

Direction: User Applications ->Sensor Module; Response required: Yes

Request message format:

Byte number	Data	Description
0	address	Current address
1	0x03	Function code

2 3	0x00 MM	Register start address
4 5	0x00 NN	Number of sensors to be read
6 7	CRC-L CRC-H	CRC Check

Response Message Format:

Byte Number	Data	Description
0	address	Current Address
1	0x03	Function Code
2	NN * 2	Data Length Sensor data (air pressure occupies 4 bytes, with 2 stored)
3	xx xx......	Equipment; Each other sensor data occupies 2 bytes, i.e. 1 register)
3+NN*2 4+NN*2	CRC_L CRC_H	CRC verification

Note: The return sensor data can be changed based on the register address and data length.

The register address (0x00MM) and corresponding sensor data are described as follows: air pressure occupies 4 bytes (2 registers), and each other sensor data occupies 2 bytes (1 register).

Register Address	Sensor Data	Number of registers occupied
0x0000	eCO2	1
0x0001	TVOC	1
0x0002	CH2O	1
0x0003	PM2.5	1
0x0004	Humidity	1
0x0005	Temperature	1
0x0006	PM10	1
0x0007	PM1.0	1
0x0008	Illuminance (Lux)	1
0x0009	MCU temperature	1
0x000A	Noise (dB)	1
0x000B	Air pressure (Pa)	2

Instructions:

① The minimum number of sensors is 00 01 and the maximum is 00 0B. When the MM value is 00, the maximum NN value can be 0B, and all sensor values can be read. When NN is 01, only eCO can be read separately2 When NN is 02, eCO can be read2 The number of TVOC

According to, and so on.

② The address at the front of the register can read data from sensors behind it when increasing the data length, but the address at the back of the register cannot read data from sensors before this address.

③ One register holds 2 bytes of data, while air pressure occupies 4 bytes, making it 2 registers. Therefore, when reading air pressure, it is necessary to read both consecutive registers, and each other sensor data occupies 2 bytes, making it 1 register.

Details are as follows:

00MM00NN	Readable data
00000001 00000002 ......	Read CO from the starting address 00002 data Read CO from the starting address 00002 , TVOC data ......

0000000D 00010001 00010002 ...... 00010007 0001000C 00020001 00020002 ...... 000B0001

Read CO from the starting address 00002 , TVOC , CH2O , PM2.5 , Humidity, temperature, PM10 , PM1.0, Illuminance, MCU temperature, noise data, air pressure data Read TVOC data from the starting address 0001 Read TVOC and CH2O data from the starting address 0001 ...... Retrieve TVOC, CH2O, PM2.5, humidity, temperature, PM10, PM1.0 data from the starting address 0001 Take TVOC, CH2O, PM2.5, humidity, and temperature from the starting address 0001, PM10 , PM1.0, Illuminance, MCU temperature, noise data, air pressure data Read CH2O data from starting address 0002 Read CH2O and PM2.5 data from the starting address 0002 ...... Read air pressure data from starting address 000B (2 registers)

For example, the address of the module is 0x01,

User sent:01 03 00 00 00 09 85 CC, can read out data from 9 sensors;

User sent:01 03 00 00 00 0B 04 0D11 sensor data (including MCU temperature) can be read out;

User sent:01 03 00 00 00 0D 84 0F, which can read out data from 12 sensors (with air pressure occupying 2 registers);

User sent:01 03 00 0B 00 02 B5 C9, Only read air pressure data (occupying 2 registers).

4)Read a frame of data

5) Return data format as follows:

Byte number	Data	Description
0	0x01	Message header
1	0x03	Function code
2	0x1A	data length
3 4	CO2_H CO2_L	CO2 data
5 6	TVOC_H TVOC_L	TVOC data
7 8	CH2O_H CH2O_L	CH2O data
9 10	PM2.5_H PM2.5 L	PM2.5 data
11 12	Humi_H Humi_L	Humidity data
13 14	Temp_H Temp_L	temperature data
15 16	PM10_H PM10_L	PM10 data
17 18	PM01_H PM01_L	PM1.0 data
19 20	Lux_H Lux_L	Illuminance (Lux) data
21 22	MCU_TEMP_H MCU_TEMP_L	MCU temperature data
23 24	dB_H dB_L	Noise (dB) data
25	Pa_byte[3]
26	Pa_byte[2]	Barometric pressure data (Pa)
27	Pa_byte[1]

28 Pa_byte[0]
29 CRC16_L 30 CRC16 H _		CRC16 verification
6)System parameter configuration 7) System parameters can be obtained or modified by reading or writing to the register addresses in the table below. 8)Note: This is an advanced feature, please use it carefully to avoid system parameter errors that may affect sensor functionality or data accuracy.
Register Address	Length (in bytes)	system parameters
0x0100	4	Sensor Map Byte 1 (front): Is it an external temperature and humidity sensor
0x0110	2	Byte 2: Sensor data user calibration bitmap, see“sensing Module bitmap ”
		Byte 1 (front): Corresponding to custom indicator items for dedicated serial port screens
0x0111	2	The sensor number Byte 2: Light transmittance of the photosensitive cover of the illuminance sensor (0-100), 0 indicates no photosensitive cover, 100 indicates no loss
0x0118	2	CO2 Calibration value, int16
0x0119	2	TVOC calibration value, int16
0x011A	2	CH2O calibration value, int16
0x011B	2	PM2.5 calibration value, int16
0x011C	2	Humidity calibration value (100 times), int16
0x011D	2	Temperature calibration value (100 times), int16
0x011E	2	PM10Calibration value, int16
0x011F	2	PM1.0Calibration value, int16
0x0120	2	Illuminance (Lux)Calibration value, int16
0x0121	2	MCU temperatureCalibration value, int16
0x0122	2	Noise (dB)Calibration value, int16
0x0123	2	atmospheric pressureCalibration value, int16

Note:

All user calibration values are signed integers, negative numbers indicate negative offsets, and the offset must be subtracted;

The user calibration values for temperature and humidity are magnified by 100 times in Celsius, for example: 250 indicates the need to add 2.5 degrees Celsius; -110 indicates the need to subtract 1.1 degrees Celsius.

For example, the address of the module is 0x01,

User sent:01 03 01 10 00 01 84 33, Read the external temperature and humidity sensor label and sensor data user calibration bitmap; User sent:01 06 01 10 00 02 04 0D, turn on the temperature and humidity user calibration switch;

User sends:01 03 01 1D 00 01 15 F0, read the temperature and humidity calibration values;

User sent:01 06 01 1D 00 FA 98 73, set the temperature user calibration value to 250, which is+2.5 degrees; User sent:01 06 01 1D 80 6E F8 1C, set the temperature user calibration value to -110, which is -1.1 degrees.

4.3 Computer Reading RS485 Data

The sensor module can be connected to the computer through a "485 to serial port" adapter to detect communication and view data. The computer can use ModBus testing tools (such as ShortBus Modbus Scanner, as shown in the figure below) to directly read data; Standard serial tools such as "Serial Assistant" can also be used to obtain data by sending query messages.

V. Calculation methods for various sensor data

. CO2 (ppm)=CO2H256+CO2L

. TVOC (ug/m3)=TVOCH_H * 256+TVOC_L

. CH2O (ug/m3)=CH2OH_H * 256+CH2O_L

. PM2.5 (ug/m3) ＝ PM2.5_H * 256 + PM2.5_L

. PM10 (ug/m3) ＝ PM10_H * 256 + PM10_L

. PM1.0 (ug/m3)=PM01:H * 256+PM01_ L_L

. Illuminance (Lux)=Lux_SH * 256+Lux_L

. Noise (dB)=dB_SH * 256+dB_L

. Temperature and humidity returned by the interface (100 times the actual data):

. Positive temperature (℃)=(Temperature_SH * 256+Temperature_L)/100, for example: T=(0x09d0)/10=2512/100=25.12 ℃

. Negative temperature (℃)

Method 1: Simply convert to a signed int type, for example: T=0xfc83/10=-893/100=-8.93 ℃

Method 2: If it is greater than 0x7fff (32767)

Then it is a negative number T=(0xfc83-65536)/10=(64643-65536)/10=-893/100=-8.93 ℃

. Humidity (% RH)=(Humidity_H * 256+Humidity_L)/100

Air pressure (Pa)=Pa-byte [3] * 224 + Pa_byte[2] * 216 + Pa_byte[1] * 28 + Pa_byte[0]

. According to air pressure calculation, altitude

is measured in Pa. Theoretically, for every 9 meters increase in altitude, atmospheric pressure decreases by 100 Pa. The standard atmospheric pressure at sea level is 101325 Pa, therefore, the following formula can be used to calculate the approximate altitude based on the pressure value (Pa):

1 , Simplified altitude formula=(101325 – Pa)/100 * 9

In addition to altitude, there are many factors that affect air pressure (such as temperature). The following formula is relatively more accurate, especially at high altitudes:

2. Calibration altitude formula=44330 * (1 – (Pa/101325)0.1903)

For example, if the measured air pressure value is 99882Pa, the altitude calculated by the two formulas is:

. Simplified altitude=(101325 – 99882)/100 * 9=129.8 meters

Calibration version altitude=44330 * (1- (99882/101325)0.1903) =120.84 meters

VI. Precautions

The first power on use requiresPreheat for more than 3 minutes

The installation position of the sensor should be at least 15-20cm above the ground, otherwise there may be large dust particles or even flocculent substances contaminating the ground, causing the fan to become entangled and stall. It is recommended to use equipment with appropriate pre filtering treatment.

. This product is a precision instrument. Please do not open the casing. Normal operation does not require knowledge of the internal conditions of the equipment. If the equipment is damaged, it must be inspected and repaired by professional personnel. Before inspection and repair, please confirm that the external power supply has been cut off..

The sensor data ensures consistency between individual products at the factory and does not use third-party testing instruments or data as comparison standards. If the user wishes the final measurement results to be consistent with a third-party testing device, the user can perform data fitting and calibration based on the actual collected results.

. This sensor is suitable for ordinary indoor environments. If the user's device is used in the following actual environments, the sensor may experience a decrease in data consistency due to excessive dust, oil, or water accumulation. For example, if the annual dust concentration exceeds 300 micrograms per cubic meter for more than 50% of the time, or exceeds 500 micrograms per cubic meter for more than 20% of the time; Oil fume environment; High water mist environment; Outdoor, etc.

VII. Sensor module bitmap

bit	sensor module
0x01	illuminance
0x02	Temperature, humidity, and air pressure
0x04	dust
0x08	air quality
0x10	Noise

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