AF5485 User Manual
- 6 -
TEL
：
020-89851175 / 89850036
www.aosong.com
v1.0-20170726
transmitter 0x10 + register start address(2 bytes) + register number(2
bytes) +
sc-bytes(1 byte) + data 0+..+ data n + CRC low byte +CRC high byte
Transmitter return format
transmitter address + 0x10 + register start address(2 bytes) + register number(2
bytes) + CRC low byte + CRC high byte
Write function code specific instructions:
1). In the internal register address, only the address 0x000C-0x001E can be written, and
others are prohibited.
2). In address 0x000C-0x001B, if the host data writing is out of the range or not in
accordance with the control logic, the transmitter register will not update the values, but
preserved.
3) 0x001C, 0x001d, 0x001E, the three registers, will be limited to the boundary value, if they
exceed the range.
4) The host should send the actual value magnified 10 times to change decimal into integer.
6.3 Error code display
0x81 illegal function code (not supported function code)
0x82 read illegal address
0x83 write illegal data (written to a not writable register address or transmitter)
6.4
Examples for communication read instructions
The host send message format:
01 03 00 00 00 02 C4 0B.
The description of the function
code is shown as below:
Send by Host
Byte
number
Message
Remarks
Slave Address
1
01
Slave that send to address 01
Function Code
1
03
Read the register
Start Address
2
0000
Start address of 0000
Register Read
Number
2
0002
Read 2 registers, 4 bytes in total
CRC Code
2
C40B
The CRC calculated by the host, the low byte first(C4)
and high byte behind(0B)
The message format returned by the sensor respond:
01 03 04 Humidity (16 bytes)
Temperature (16 bytes) CRC check code