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Function Code

1

0x03

Read register

Starting address

1

0x00

Register start address is 0x00

Number of registers

1

0x04

Read the number of register

Sensor response message format returned:

Slave response

Byte count

Transmitting information

Remarks

Function Code

1

0x03

Read register

Returns the number of bytes

1

0x04

Returns 4 of 4 byte register

Register 1

1

0x01

Address for the content of 0x00 (high humidity bytes)

Register 2

1

0XF4

Address for the content of 0x01 (low humidity bytes)

Register 3

1

0x00

Address for the content of 0x01 (low humidity bytes)

Register 4

1

0XFA

Address for the content 0x03 (temperature low byte)

CRC code

2

31A5

Sensors calculate the CRC code returned, low byte first;

Numerical calculation:

From the temperature and humidity sensor value is read back, as long as the value into decimal

number 10 is divided by the corresponding values of temperature and humidity, corresponding

temperature unit ℃, humidity unit is% RH. Such as the above data read back:

Humidity: 01F4 = 1×256+15×16+4 =500 => humidity = 500÷10=50.0%RH;

Temperature: 00FA= 15×16+10 = 250 => temperature = 250÷10 = 25.0℃ Note:

CRC

verification code calculated by the CRC code drawn, then the sensor on the transmission of CRC

codes ratio; same, then that data is received correctly, otherwise that data has errors.

2. Function code "10": Write multiple registers to sensor

Host code can use this feature to save multiple data storage sensor. Single AM2321 sensor

register is a byte, or 8 bits. Sensor allows you to save a maximum of 10 data registers. Thus, the

single most host to the sensor to save up to 10 registers. Over 10, the sensor will return the

corresponding error code.

The host sends the write frame format:

START + (I C address + W) + function code (0x10) + start address register number + save data

+ CRC + STOP

The host reads the confirmation instruction:

START + (I C address + R) + read sensor data returned + STOP

Sensor response frame format:

Function code (0x10) + start address + number + CRC register

For example: The host should be saved to address 10,11 ,01,02 sensors to register.

2

2

The host sends

Byte count

Transmitting information

Remarks

Sensor address

1

0XB8

Sensor C address (0xB8) + W (0)

Function Code

1

0x10

Write Multiple Registers

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