Humidity and temperature data conversion

HTS221

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Humidity and temperature data conversion

The Registers in 30h..3Fh address range contain calibration coefficients. Every sensor

module has individual coefficients. Before the first calculation of temperature and humidity,

the master reads out the calibration coefficients.

(u8) is the unsigned 8-bit quantity, and (s16) the signed 16-bit quantity using 2’s

complement format. In the following example, the two steps required to calculate

temperature and relative humidity output values are described. The T0 and T1 calibration

temperature values are actually composed of 10 bits (unsigned), where the 2 MSB are in

reg 35h, and the 8 LSB are in regs 32h and 33h, respectively. T0 and T1 are the actual

calibration temperature values multiplied by 8.

Table 19. Decoding the coefficients in the sensor Flash

Addr

Variable

Format

b7

b6

b5

b4

b3

b2

b1

b0

Output registers

28

H_OUT

(s16)

H7

H6

H5

H4

H3

H2

H1

H0

29

H15

H14

H13

H12

H11

H10

H9

H8

2A

T_OUT

(s16)

T7

T6

T5

T4

T3

T2

T1

T0

2B

T15

T14

T13

T12

T11

T10

T9

T8

Calibration registers

30

H0_rH_x2

(u8)

H0.7

H0.6

H0.5

H0.4

H0.3

H0.2

H0.1

H0.1

31

H1_rH_x2

(u8)

H1.7

H1.6

H1.5

H1.4

H1.3

H1.2

H1.1

H1.0

32

T0_degC_x8

(u8)

T0.7

T0.6

T0.5

T0.4

T0.3

T0.2

T0.1

T0.0

33

T1_degC_x8

(u8)

T1.7

T1.6

T1.5

T1.4

T1.3

T1.2

T1.1

T1.0

34

Reserved

(u16)

35

T1/T0 msb

(u2),(u2)

Reserved

T1.9

T1.8

T0.9

T0.8

36

H0_T0_OUT

(s16)

76

5

4

3

2

1

0

37

15

14

13

12

11

10

9

8

38

Reserved

39

3A

H1_T0_OUT

(s16)

76

5

4

3

2

1

0

3B

15

14

13

12

11

10

9

8

3C

T0_OUT

(s16)

76

5

4

3

2

1

0

3D

15

14

13

12

11

10

9

8

3E

T1_OUT

(s16)

76

5

4

3

2

1

0

3F

15

14

13

12

11

10

9

8