HS300x Datasheet

© 2020 Renesas Electronics Corporation

14

April 22, 2020

6.9 Setting the Measurement Resolution

The HS300x series relative humidity and temperature measurement resolutions can be set independently to 8, 10, 12, or 14-bits by writing to

the non-volatile memory, and are initially set to 14-bits by default. The procedure to set the humidity sensor resolution is illustrated in Figure

19. The relative humidity and temperature resolution can be read in registers 0x06 and 0x11, respectively, or written in registers 0x46 or 0x51.

The resolution information is stored in bits [11:10] of these registers, as listed in the Table 9. All of the other bits in these registers must be left

unchanged. As such, before writing new resolution settings, the contents of the read registers must be read, and only bits [11:10] can be

changed in the write registers. Once bits [11:10] are changed to set the desired resolution, the entire register must be written back to the HS300x

sensor.

Figure 19. Sequence of Commands to Change the Relative Humidity Resolution

Table 9.

Register Values for Different Resolution Settings

Resolution register

bits [11:10]

Resolution

(bits)

8

10

12

14

The sensor non-volatile memory requires 120µs to load the data into the registers after step 1, and requires 14ms to write the data after step

4. Failure to comply with these processing times may result in data corruption and introduce errors in sensor measurements. The procedure to

change the temperature sensor resolution is the same as that depicted in Figure 19, except the register address in Step 1 must be set to 0x11

and the register address in Step 4 will be 0x51.

6.10Reading the HS300x ID Number

The sensor ID is a 32-bit number, and can be read in a similar fashion as illustrated in steps 1 and 2 of Figure 19, using the appropriate register

address values. The ID number is stored in two registers, with the upper and lower 16 bits stored in register addresses 0x1E and 0x1F,

respectively.