LSM9DS1 SDO not tri-stated

[DMona.1]

I need several LSM9DS1 sensors one the same SPI line. However, I noticed that when CS is high, SDO (aka MISO) is not tri-stated but pulled down to GND.

I thought this was due to the default double-interface (SPI/I2C), so I have enabled the I2C_DISABLE bit in REG9, but nothing has changed.

Thus, I need a tri-state buffer on MISO lines of each sensor.

But the answer here seems different: https://community.st.com/s/question/0D50X00009XkXIPSA3/lsm9ds1-on-single-spi-bus-with-other-devices?t=1611822778772

Anyone can shed some light on this?

Thanks!

[Eleon BORLINI]

Hi @DMona.1​ ,

but did you tested at least two LSM9DS1 on the same SPI lines (sharing all the line except from the CS)?

Because it should anyway work, since any pull-down on SDO (aka MISO) is very weak and is dominated by the SPI digital machine.

The suggestion in the post you mentioned (the use of I2C_DISABLE bit) is always suggested when using multiple devices but it is intended to prevent an unlikely cross-talk between I2C and SPI interfaces when the CS is in high state for the non-communicating devices, and not to change the status of the SPI communication pins.

Please let me know if you are facing issues using devices together.

-Eleon