User manual

AHHYTM_E2.2.1
15/23
Application Note
Humidity Module
HYT
4.5 I2C pull up resistor
5. I
2
C Address Change
To change the I
2
C-address of the sensor module, the module must be switched into the Command-Mode. The
switching is performed by sending the start-command-mode message over I
2
C-bus no later than 10 ms after Power-
On reset. Each command-mode message is 4 byte long, like shown in table 1.
S 6 5 4 3 2 1 0 W A 7 6 5 4 3 2 1 0 A 7 6 5 4 3 2 1 0 A 7 6 5 4 3 2 1 0 A P
S 0 1 0 1 0 0 0 0 A C C C C C C C C A D D D D D D D D A D D D D D D D D A P
Slave Address Command Byte Command Data [15:8] Command Data [7:0]
Table 1
SlaveAddress: 0x28 default value
Command-Byte: 0xA0 start command-mode
0x1C read congurationsparameter that includes the I
2
C-address
0x5C write congurationsparameter that includes the I
2
C-address
0x80 end of command-mode, start normal-mode