BMP388 CSB pin

[trodenas]

HI,

    I am developing a new system with BMP388 sensor. In datasheet (5.1 Interface selection) it says " If CSB is connected to VDDIO, the I2C interface is active" and also in 5.2 I2C Interface section it says "CSB is not used and is left open". It is confused to me. I have only 4 pins for I2C (VDD, GND, SDA and SCL). Then how i must connect CSB pin, connected to VDDIO or floating? I wait for your reply.

Best Regards

[BSTRobin]

Hello trodenas,

In BMP388 data sheet, host had two HW connection method to BMP388: SPI, I2C. When you design your HW you will consider which connection interface you will use. So when you use I2C interface, CSB was connected VDDIO. when you use SPI interface, CSB workes as CS pin in SPI.

[trodenas]

I understan but then,  ¿Why in 5.2 I2C Interface section it says "CSB is not used and is left open"?

[BSTRobin · Accepted solution]

Hello trodenas,

You could understand when I2C interface was used, CSB was not used for I2C interface communication, but CSB was used as interface selection and was recommended to be connected VDDIO for POR interface selection.