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Version 3 – August 2020

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4.13 Checksum Calculation

The 8-bit CRC checksum transmitted after each data word is generated by a CRC algorithm. Its properties are displayed

in Table 19. The CRC covers the contents of the two previously transmitted data bytes. To calculate the checksum only

these two previously transmitted data bytes are used.

Property

Value

Name

CRC-8

Width

8 bit

Protected data read and/or write data

Polynomial

Initialization

0xFF

Reflect input

False

Reflect output False

Final XOR

0x00

Examples

CRC (0xBEEF) = 0x92

Table 19: I2C CRC properties.

4.14 Conversion of Signal Output

Measurement data is always transferred as 16-bit values (unsigned integer). These values are already linearized and

compensated for temperature and supply voltage effects. Converting those raw values into a physical scale can be

achieved using the following formulas.

Relative humidity conversion formula (result in %RH):

1







16

RH

2

S

100

RH

Temperature conversion formula (result in °C & °F):

 

 

1

1

























16

T

16

T

2

S

315

49

F

T

2

S

175

45

C

T