The GY-BMP280 module operates from 3.3V so requires 3.3V power and must be
driven with 3.3V logic levels. If needed to operate at 5V, it can be done using
voltage regulator and level shifters as it doesn’t contain one. It is typically
recommended to operate it on 3.3V and maximum at 3.6VDC. The module GY-BMP280
module simply supports both I²C and SPI interfaces and comes with default I²C
address of 0x76. The Chip Select (CSB) and Serial Data Output (SDO) pins of the
BMP 280 are necessary only when SPI-based (four-wire) communication is applied.
I2C is a two wire interface SDA SCK.
Leave pin 6 of the module (SDO) unconnected to set the I²C address to 0x76 – the on-board resistor pulls the SDO pin low setting the address to 0x76.
To change the I²C address to 0x77, connect pin 6 of the module (SDO) to Vcc which would typically be the 3.3V supply.
Pin 5 of the module (CSB) must be connected to Vcc to select the I²C interface. This is already done by an on-board pull-up resistor, so pin 5 can be left disconnected when using the I²C interface.
|Pin No.||Pin Name||Pin Description|
|1||VCC||Power source of 3.3VDC|
|5||CSB||CSB pin to GND to have SPI and to VCC(3.3V) for I2C. It’s an input to the chip.|
|6||SDO||Serial Data Out / Master In Slave Out pin, for data sent from the BMP280 to your processor|