SI7013 Datasheet, PDF (29/43 Pages) Silicon Laboratories – I2C HUMIDITY AND TWO-ZONE TEMPERATURE SENSOR

5.5. Firmware Revision
The internal firmware revision can be read with the following I2C transaction:
Si7013
S
Slave
Address
WA
0x84
A
0xB8
AS
Slave
Address
RA
FWREV
A NA P
The upper nibble of the FWREV byte corresponds to the major firmware revision number, while the lower nibble of
the FWREV byte corresponds to the minor firmware revision number. Therefore, firmware revision 1.0 would be
encoded as 0x10 in the FWREV byte.
5.6. Heater
The Si7013 contains an integrated resistive heating element that may be used to raise the temperature of the
sensor. This element can be used to test the sensor, to drive off condensation, or to implement dew-point
measurement when the Si7013 is used in conjunction with a separate temperature sensor such as another Si7013
(the heater will raise the temperature of the internal temperature sensor).
The heater can be activated using HEATER[2:0], the three least-significant bits in User Register 3. Turning on the
heater will reduce the tendency of the humidity sensor to accumulate an offset due to "memory" of sustained high
humidity conditions. Five different power levels are available. The various settings are described in Table 18.
Table 19. Heater Control Settings
HEATER[3:0] Typical Current
Draw^* (mA)
0000
3.09
0001
9.18
0010
15.24
...
...
0100
27.39
...
...
1000
51.69
...
...
1111
94.20
*Note: Assumes VDD = 3.3 V.
Rev. 0.95
29