www.sensirion.com / D1

Version 4

– December 2022

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Command

Hex code

Fetch Data

0x E0 00

Table 10

. Fetch Data command (clear blocks are controlled by the microcontroller, grey blocks by the sensor)

4.7 Break command/ Stop Periodic Data Acquisition Mode

The periodic data acquisition mode can be stopped using the break command shown in Table 11.

It is recommended to stop the periodic data acquisition prior to sending another command (except

Fetch Data command) using the break command. Upon reception of the break command the

sensor will abort the ongoing measurement and enter the single shot mode. This takes 1 ms.

Command

Hex Code

Break

0x3093

Table 11. Break command (clear blocks are controlled by the microcontroller, grey blocks by the sensor).

4.8 Reset

A system reset of the STS32/33-DIS can be generated externally by issuing a command (soft reset)

or by sending a pulse to the dedicated reset pin (nReset pin). Additionally, a system reset is

generated internally during power-up. During the reset procedure the sensor will not process

commands. In order to achieve a full reset of the sensor without removing the power supply, it is

recommended to use the nRESET pin of the STS32/33-DIS.

Interface Reset

If communication with the device is lost, the following signal sequence will reset the serial interface:

While leaving SDA high, toggle SCL nine or more times. This must be followed by a Transmission

Start sequence preceding the next command. This sequence resets the interface only. The status

register preserves its content.

Soft Reset / Re-Initialization

The STS32/33-DIS provides a soft reset mechanism that forces the system into a well-defined state

without removing the power supply. When the system is in idle state the soft reset command can

be sent to the STS32/33-DIS. This triggers the sensor to reset its system controller and reloads

calibration data from the memory. In order to start the soft reset procedure the command as shown

in Table 12 should be sent. It is worth noting that the sensor reloads calibration data prior to every

measurement by default.

I2C Address

Temperature MSB

16-bit command

I2C write header

I2C read header

I2C Address

Temperature LSB

16-bit temperature value

Checksum

S

W

P

CRC

R

Command LSB

Command MSB

S

P