BMP085

Data sheet

Bosch Sensortec

Rev. 1.2

Page 18

15 October 2009

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as copying and passing on to third parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.

Specifications are subject to change without notice.

S

ACKS

Module address

write 0xEE

ACKS

Register address

e.g. 0xF6

MSB e.g.

ADC result 0x5C

ACKS

Module address

read 0xEF

Restart

ACKM

LSB e.g.

ADC result 0x96

NACKM

SCL

SDA

P

4.5 Read A/D conversion result or E

To read out the temperature data word UT (16 bit), the pressure data word UP (16 to 19 bit) and

the E

After the start condition the master sends the module address write command and register

address. The register address selects the read register:

E

0xAA to 0xBF

Temperature or pressure value UT or UP

0xF6 (MSB), 0xF7 (LSB), optionally 0xF8 (XLSB)

Then the master sends a restart condition followed by the module address read that will be

acknowledged by the BMP085 (ACKS). The BMP085 sends first the 8 MSB, acknowledged by

the master (ACKM), then the 8 LSB. The master sends a "not acknowledge" (NACKM) and

finally a stop condition.

Optionally for ultra high resolution, the XLSB register with address 0xF8 can be read to extend

the 16 bit word to up to 19 bits; refer to the application programming interface (API) software

Timing diagram read 16 bit A/D conversion result: