Data sheet

BMP180

Page 21

BST-BMP180-DS000-12 | Revision 2.8 | May 2015

Bosch Sensortec

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Note: Specifications within this document are subject to change without notice.

5.4 Start temperature and pressure measurement

The timing diagrams to start the measurement of the temperature value UT and pressure value UP

are shown below. After start condition the master sends the device address write, the register

address and the control register data. The BMP180 sends an acknowledgement (ACKS) every 8

data bits when data is received. The master sends a stop condition after the last ACKS.

Figure 8: Timing diagram for starting pressure measurement

Abbreviations:

S

Start

P

Stop

ACKS

Acknowledge by Slave

ACKM

Acknowledge by Master

NACKM

Not Acknowledge by Master

Table 8: Control registers values for different internal oversampling_setting (oss)

Measurement

Control register value

(register address 0xF4)

Max. conversion time

[ms]

Temperature

0x2E

4.5

Pressure

(oss = 0)

0x34

4.5

Pressure

(oss = 1)

0x74

7.5

Pressure

(oss = 2)

0xB4

13.5

Pressure

(oss = 3)

0xF4

25.5