Datasheet

BMP280 Digital Pressure Sensor

Page 21

BST-BMP280-DS001-19 | Revision 1.19 | January 2018

Bosch Sensortec

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parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.

Note: Specifications within this document are subject to change without notice. Not intended for publication.

Compensation of

Number of clock cycles (ARM Cortex-M3)

32 bit integer

64 bit integer

Double precision

Temperature

~46

–

Pressure

~1400

~5400

7

3.11.2 Trimming parameter readout

The trimming parameters are programmed into the devices’ non-volatile memory (NVM) during

production and cannot be altered by the customer. Each compensation word is a 16-bit signed or

unsigned integer value stored in two’s complement. As the memory is organized into 8-bit words,

two words must always be combined in order to represent the compensation word. The 8-bit

registers are named calib00…calib25 and are stored at memory addresses 0x88…0xA1. The

corresponding compensation words are named dig_T# for temperature compensation related

values and dig_P# for pressure compensation related values. The mapping is shown in Table 17.

Table 17: Compensation parameter storage, naming and data type

Register

Address

LSB / MSB

Register

content

Data type

0x88 / 0x89

dig_T1

unsigned short

0x8A / 0x8B

dig_T2

signed short

0x8C / 0x8D

dig_T3

signed short

0x8E / 0x8F

dig_P1

unsigned short

0x90 / 0x91

dig_P2

signed short

0x92 / 0x93

dig_P3

signed short

0x94 / 0x95

dig_P4

signed short

0x96 / 0x97

dig_P5

signed short

0x98 / 0x99

dig_P6

signed short

0x9A / 0x9B

dig_P7

signed short

0x9C / 0x9D

dig_P8

signed short

0x9E / 0x9F

dig_P9

signed short

0xA0 / 0xA1

reserved

reserved

3.11.3 Compensation formula

Please note that it is strongly advised to use the API available from Bosch Sensortec to perform

readout and compensation. If this is not wanted, the code below can be applied at the user’s risk.

Both pressure and temperature values are expected to be received in 20 bit format, positive,

stored in a 32 bit signed integer.