TH02

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To read a register on the TH02, 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 TH02 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 TH02 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 TH02 from which the data should be transferred. After

the TH02 acknowledges this byte, the master issues a repeated start command (Sr) indicating that a new transfer

is to take place. The TH02 is addressed once again with the R/W bit set to 1, indicating a read operation. The

TH02 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 18). 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 TH02 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 19).

Sequence to Read from a Single Register

S

Slave Address

W

A

Address Pointer

A

Sr

Slave Address

R

A

Register Data

A

P

Sequence to Read Device ID

S

0x40

0

A

0x11

A

Sr

0x40

1

A

ID

A

P

Sequence to Read RDY bit

S

0x40

0

A

0x00

A

Sr

0x40

1

A

—

RDY

A

P

Sequence to Read Conversion Result

S

Slave

Address

W

A

Address

Pointer

A

Sr

Slave

Address

R

A

Register 1

Data

A

Register 2

Data

A

P

S

0x40

0

A

0x01

A

Sr

0x40

1

A

Data H

A

Data L

A

P