OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

SI7015-A10-GMR

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P30P31-P33P34-P36P37-P39
Si7015-A10
22 Rev. 1.0
5.1.4. Fast Conversion Mode
The time needed to perform a temperature or RH measurement can be reduced from 5.8 ms (typical) to 2.6 ms
(typical) by setting FAST (D5) in CONFIG (register 0x03). Fast mode reduces the total power consumed during a
conversion or the average power consumed by the Si7015 when making periodic conversions. It also reduces the
resolution of the measurements.
5.1.5. Heater
The Si7015 relative humidity sensor contains an integrated, resistive heating element that may be used to raise the
temperature of the humidity sensor. This element can be used to drive off condensation or to implement dew-point
measurement when the Si7015 is used in conjunction with a separate temperature sensor such as another Si7015.
The heater can be activated by setting HEAT (D1) in CONFIG (register 0x03). Turning on the heater will reduce the
tendency of the humidity sensor to accumulate an offset due to “memory” of sustained high humidity conditions.
When the heater is enabled, the reading of the on-chip temperature sensor will be affected (increased).
5.1.6. Device Identification
The Si7015 device and its revision level can be determined by reading ID (register 0x11). Table 15 lists the values
for the various device revisions and may include revisions not yet in existence.
Table 15. Device ID Revision Values
Device ID Value Device
Type
Revision
Level
D[7:4] D[3:0]
1111 0000 Si7015 A
Si7015-A10
Rev. 1.0 23
5.2. I
2
C Operation
The format of the address byte is shown in Table 16.
5.2.1. I
2
C Write Operation
To write to a register on the Si7015, the master should issue a start command (S) followed by the slave address,
0x40. The slave address is followed by a 0 to indicate that the operation is a write. Upon recognizing its slave
address, the Si7015 issues an acknowledge (A) by pulling the SDA line low for the high duration of the ninth SCL
cycle. The next byte the master places on the bus is the register address pointer, selecting the register on the
Si7015 to which the data should be transferred. After the Si7015 acknowledges this byte, the master places a data
byte on the bus. This byte will be written to the register selected by the address pointer. The Si7015 will
acknowledge the data byte, after which the master issues a Stop command (P). See Table 17.
Table 16. I
2
C Slave Address Byte
A6 A5 A4 A3 A2 A1 A0 R/W
10000001/0
Master Slave
Table 17. I
2
C Write Sequence
Sequence to Write to a Register
S Slave Address W
A Address Pointer ARegister DataAP
Sequence to Start a Relative Humidity Conversion
S0x40 0
A 0x03 A 0x01 AP
Sequence to Start a Temperature Conversion
S0x40 0
A 0x03 A 0x11 AP
Si7015-A10
24 Rev. 1.0
5.2.2. I
2
C Read Operation
To read a register on the Si7015, the master must first set the address pointer to indicate the register from which
the data is to be transferred. Therefore, the first communication with the Si7015 is a write operation. The master
should issue a start command (S) followed by the slave address, 0x40. The slave address is followed by a 0 to
indicate that the operation is a write. Upon recognizing its slave address, the Si7015 will issue an acknowledge (A)
by pulling the SDA line low for the high duration of the ninth SCL cycle. The next byte the master places on the bus
is the register address pointer selecting the register on the Si7015 from which the data should be transferred. After
the Si7015 acknowledges this byte, the master issues a repeated start command (Sr) indicating that a new transfer
is to take place. The Si7015 is addressed once again with the R/W bit set to 1, indicating a read operation. The
Si7015 will acknowledge its slave address and output data from the previously-selected register onto the data bus
under the control of the SCL signal, the master should not acknowledge (A
) the data byte and issue a stop (P)
command (see Table 22). However, if a RH or Temperature conversion result (two bytes) is to be read, the master
should acknowledge (A) the first data byte and continue to activate the SCL signal. The Si7015 will automatically
output the second data byte. Upon receiving the second byte, the master should issue a not Acknowledge (A
)
followed by a stop command. (See Table 23.)
Table 18. I
2
C Read Sequence for a Single Register
Sequence to Read from a Single Register
S Slave Address W
A Address Pointer ASr Slave Address R A Register Data A P
Sequence to Read Device ID
S0x40 0
A 0x11 ASr 0x40 1 A ID A P
Sequence to Read RDY
bit
S0x40 0
A 0x00 ASr 0x40 1 A — RDY A P
Table 19. I
2
C Read Sequence for RH or Temperature Conversion Result
Sequence to Read Conversion Result
SSlave
Address
W
AAddress
Pointer
ASr Slave
Address
R A Register 1
Data
A Register 2
Data
A P
S0x40 0
A0x01ASr 0x40 1 A Data H A Data L A P
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P30P31-P33P34-P36P37-P39

SI7015-A10-GMR

Mfr. #:
Buy SI7015-A10-GMR
Manufacturer:
Silicon Labs
Description:
Board Mount Humidity Sensors Digital RH ( 4.5% max) & temperature sensor, commercial grade
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet