BMI085

[ShauneBEE]

In Section 7.2: Connection Diagram SPI on page 42 in the BMI085 datasheet,  they suggest connecting the 2 SDOutput pins together to one MISO line for SPI communications.  Has anyone done this to good effect?  You typically don't connect outputs together.  I can't imagine it staying in the datasheet if it doesn't work.  Can anyone help me understand what's going on inside the chip to assuage my concerns about connecting 2 outputs together?  My schematic capture has anxiety about it too.

It also says in Section 6: Digital Interface on page 33, "Important: Please also note that as the pins of the package are shared between accelerometer and gyroscope part, it is not advisable to configure different interfaces for the two parts."  That seems to confirm what they did in the connection diagram.

Any shared experience or knowledge would be greatly appreciated.  I would like to measure twice and cut once.

Thank you.

Shaune

[ShauneBEE]

Meant to add a link to the datasheet for convenience.

https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmi085-ds001.pdf

[BSTRobin]

Hello ShauneBEE,

In Section 7.2: Connection Diagram SPI on page 42 in the BMI085 datasheet, they suggest connecting the 2 SDOutput pins together to one MISO line for SPI communications. Has anyone done this to good effect? You typically don't connect outputs together. I can't imagine it staying in the datasheet if it doesn't work. Can anyone help me understand what's going on inside the chip to assuage my concerns about connecting 2 outputs together? My schematic capture has anxiety about it too.
Reply: accel and gyro are two independent parts in the sensor, which can be seen from BMI085 block diagram. It can be understood that accel and gyro are two SPI save devices. They share SCK, MISO and MOSI pins and can be accessed through CS.

It also says in Section 6: Digital Interface on page 33, "Important: Please also note that as the pins of the package are shared between accelerometer and gyroscope part, it is not advisable to configure different interfaces for the two parts." That seems to confirm what they did in the connection diagram.
Reply: it means the same pin can't be used for both I2C and SPI. For example, pin 8 and pin 9 are used for SPI communication and will no longer be used for I2C communication.