HTU31D RH/T SENSOR IC

Digital Relative Humidity & Temperature Sensor

REV3 01/2021

Page 11

Read Diagnostic

A diagnostic register is available to check if the humidity and temperature are working properly, if the humidity or temperature

are out of specified range, the heater and the memory status:

Figure 12 Read Serial number command

Note: The not acknowledge (nack) and stop at the end of the reading is mandatory, otherwise the chip may block the SDA.

Diagnostic Register

7

6

5

4

3

2

1

0

NVM error

(NVM err)

Humidity

under/overrun

(Hout)

Humidity

high error

(Hhigh)

Humidity

low error

(Hlow)

Temperature

under/overrun

(Tout)

Temperature

high error

(Thigh)

Temperature

low error

(Tlow)

Heater on

(Hon)

Table 12 Diagnostic Register

Abbreviation

Description

NVM error (NVM err)

bit is set if the CRC of the NVM has failed (CRC is done on the register copy)

Humidity under/overrun (Hout)

bit is set if the humidity is truncated to 0 or the max value of 2^16-1

Humidity high error (Hhigh)

bit is set if the humidity calculation results above 120 %RH

Humidity low error (Hlow)

bit is set if the humidity calculation results below -10 %RH

Temperature under/overrun (Tout)

bit is set if the temperature is truncated to 0 or the max value of 2^16-1

Temperature high error (Thigh)

bit is set if the temperature calculation results above 150 °C

Temperature low error (Tlow)

bit is set if the temperature calculation results below -50 °C

Heater on (Hon)

bit is set if the heater is on

Table 13 Diagnostic Register Bits Description