Instructions for Ten in One Air Quality Sensor

I. Overview of Communication Protocol

1. Default Communication Parameters

• Baud Rate: 9600
• Data Bits: 8
• Check Bits: None
• Stop Bit: 1(i.e.9600/8/N/1)
• Default Device Address: 0x01
• Response Time:<100ms

2. CRC Check

• Algorithm: CRC-16/Modbus (Polynomial0x8005)
• checksum format: 2 bytes, with the high-order bits first (e.g.CRC_H CRC_L).
• Calculation tool: Refer toCRCToolOr the code in Chapter IX of the specification sheet.

2, Detailed explanation of protocol functions

1. Read device address and firmware version

FunctionObtain the current device address and firmware version number.

Request format (host → sensor)

Example command:

FE 11 00 00 00 01 28 06

Response format (sensor → host)

Example response:

01 11 02 12 01 70 5C

Parse:

• Firmware Version:V1.2
• Device address:0x01

2. Modify device address

Function: Change the Modbus address of the device (range1~247).

Request format (host → sensor)

Example command(modify address to0x02):

01 06 00 00 00 02 08 0B

Response format (sensor → host)

Consistent with the request format, return the modified address confirmation.

Example Response:

01 06 00 00 00 02 08 0B

Explanation: If the response data is the same as the request, it indicates that the modification was successful.

3. Read sensor data

functionRead sensor data from a specified register (supports reading multiple sensors at once).

Request format (host → sensor)

Example Command(Read All 11 Sensor Data):

01 03 00 00 00 0B C5 CD

Response Format (Sensor → Host)

Example response(Partial data):

01 03 16 00 96 00 64 00 32 00 30 00 28 00 1E 01 2C 00 0A 00 14 70 5C

Parse:

• 00 96→ eCO₂ = 150 ppm
• 00 64→ TVOC = 100 ppb
• 00 32→ CH₂O = 50 μg/m³
• Temperature and humidity data:
• Humidity0x012C→ 300 → 300/100 = 30.0%RH
• Temperature:0x000A→ 10 → 10/100=0.10 ℃

4. System Parameter Configuration (Advanced Function)

4.1 Read/Set Baud Rate

Register Address: 0x0103(Baud Rate Code See Appendix Table).

Read baud rate request:

01 03 01 03 00 01 CRC

Set baud rate request(set to 115200):

01 06 01 03 00 07 CRC

4.2 Calibration sensor data

Register address:

• Temperature calibration:0x011D
• Humidity Calibration:0x011C

Example Command(Temperature Calibration+2.5 ℃):

01 06 01 1D 00 FA 98 73

Explanation:

• 00 FA→ 250 (i.e. 250/100=2.5 ℃)
• Negative values need to be converted to complement codes (such as0xFF9C→ -100 → -1.00 ℃).

III. Data Analysis Method

1. Calculation Formula

2. Symbolic number processing

• Method 1: Directly convert to a signed integer (such as0xFF9C→ -100).
• Method 2: If the value is greater than 32767, then真实值 = (原始值 - 65536) / 100.

IV. Precautions

1. Preheating Time: The VOC module needs to be preheated for at least 3 minutes, and other sensors can be used immediately after power on.
2. Installation Requirements:

• Installation height should be ≥ 15cm to avoid ground dust pollution.
• Avoid high dust (>300 μ g/m ³), oil fumes, or high humidity environments.

1. Calibration Warning:

• Advanced functions should be operated with caution, as incorrect modifications may result in abnormal data.
• The calibration value needs to be adjusted according to the actual environment, and it is recommended to record the factory default value.

1. CRC Check: All commands must contain the correct CRC, otherwise the device will not respond.

V. Appendix

1. Sensor Register Address Table

2. Baud rate code table

3. CRC calculation code (C language example)

uint16_t CRC16_Check(const uint8_t *pushMsg, uint8_t usDataLen) {
    uint8_t uchCRCHi = 0xFF, uchCRCLo = 0xFF;
    uint8_t uIndex;
    while (usDataLen--) {
        uIndex = uchCRCLo ^ *pushMsg++;
        uchCRCLo = uchCRCHi ^ auchCRCHi[uIndex];
        uchCRCHi = auchCRCLo[uIndex];
    }
    return (uint16_t)(uchCRCHi << 8 | uchCRCLo);
}

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