HS300x-ML1 Datasheet

R36DS0016EU0001 Rev.0.01

Nov 8, 2021

Page 13

5.7

Status Bits

The status bits are used to indicate the current state of the fetched data. The two MSBs of the humidity data byte

are the status bits (see the following table).

Table 6. Status Bits

Status Bits

Definition

00B

Valid Data: Data that has not been fetched since the last measurement cycle.

01B

Stale Data: Data that has already been fetched since the last measurement cycle.

Note: If a data fetch is performed before or during the first measurement after power-on reset, then the

stale status will be returned, but this data is actually invalid since the first measurement has not been

completed.

5.8

Accessing the Non-volatile Memory

The HS300x-ML1 series non-volatile memory stores its measurement resolution setting and its ID number. To

change the sensor resolution or read the ID number, the master must place the HS300x-ML1 into programming

mode while the device is powering up. The following figure shows the sequence of commands needed to enter

the programming mode, which must be sent within 10ms after applying power to the sensor. The master must

send the I2C address and a Write bit followed by the command 0xA0|0x00|0x00.

Figure 17. Sequence of Commands to Enter Programming Mode

This command takes 120

µs to process, after which the master has access to the non-volatile memory registers

listed in the following table. All of these registers are 16 bits wide.

To return to normal sensor operation and perform measurements, the master must send the I2C address and a

Write bit, followed by the command: 0x80|0x00|0x00.

Table 7. Non-volatile Memory Registers

Address

Register Description

0x06

Humidity Sensor Resolution – Read Register (bits [11:10])

0x46

Humidity Sensor Resolution – Write Register (bits [11:10])

0x11

Temperature Sensor Resolution – Read Register (bits [11:10])

0x51

Temperature Sensor Resolution – Write Register (bits [11:10])

0x1E

Read Sensor ID – Upper 2 bytes

0x1F

Read Sensor ID – Lower 2 bytes