BMP280 datasheet(28/49 Pages) BOSCH

28 / 49 page

Bosch Sensortec | BMP280 Data sheet

28 |

Modifications reserved | Data subject to change without notice

Document number: BST-BMP280-DS001-26 Revision_1.26_102021

GND

VDDIO

output driver (only for SDI)

SDI /SCL

high-z level shifter

GND

Figure 6: SDI/SCK ESD drawing

The 7-bit device address is 111011x. The 6 MSB bits are fixed. The last bit is changeable by SDO

value and can be changed during operation. Connecting SDO to GND results in slave address

1110110 (0x76); connection it to VDDIO results in slave address 1110111 (0x77), which is the same as

BMP180’s I²C address. The SDO pin cannot be left floating; if left floating, the I²C address will be

undefined.

The I²C interface uses the following pins:

•

SCK: serial clock (SCL)

•

SDI:

data (SDA)

•

SDO: Slave address LSB (GND = ‘0’, VDDIO = ‘1’)

CSB must be connected to VDDIO to select I²C interface. SDI is bi-directional with open drain to GND: it

must be externally connected to VDDIO via a pull up resistor. Refer to chapter 6 for connection

instructions.

The following abbreviations will be used in the I²C protocol figures:

•

Start

•

Stop

•

ACKS

Acknowledge by slave

•

ACKM

Acknowledge by master

•

NACKM

Not acknowledge by master

5.2.1

I²C write

Writing is done by sending the slave address in write mode (RW = ‘0’), resulting in slave address

111011X0 (‘X’ is determined by state of SDO pin. Then the master sends pairs of register addresses

and register data. The transaction is ended by a stop condition. This is depicted in Figure 7.

Start

RW ACKS

ACKS

bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0

…

ACKS

ACKS Stop

…

bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0

Slave Address

Control byte

Data byte

Control byte

Data byte

Figure 7: I²C multiple byte write (not auto-incremented)

BMP280 Folha de dados(PDF) 28 Page - Bosch Sensortec GmbH

BMP280 Folha de dados(HTML) 28 Page - Bosch Sensortec GmbH

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49

Folha de dados Download

Ligação URL