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@rarin2din wrote:
Nucleo-IKSO1A3. What software will I need to run examples on expansion bd sensors ?
The place to start is always the Product Page for the board; in this case:
https://www.st.com/en/evaluation-tools/x-nucleo-iks01a3.html
There you would normally find all the available resources & collateral - User Manual, other documentation, schematics, software, etc.
Unfortunately, this board is shown as Obsolete:

So a lot of the support has been withdrawn.
But the User Manual & schematics are still there, and most of the individual sensors are still 'Active':
LSM6DSO accelerometer: https://www.st.com/en/mems-and-sensors/lsm6dso.html
LIS2MDL magnetometer: https://www.st.com/en/mems-and-sensors/lis2mdl.html
LIS2DW12 accelerometer: https://www.st.com/en/mems-and-sensors/lis2dw12.html
LPS22HH pressure sensor: https://www.st.com/en/mems-and-sensors/lps22hh.html
The STTS751 temperature sensor is NRND: https://www.st.com/en/mems-and-sensors/stts751.html
Look on the 'Tools & Software' tabs of these Product Pages to find software support; eg, C-Driver-MEMS
The HTS221 humidity and temperature sensor Product Page seems to be missing (presumably obsolete?), but the datasheet is still available - if you search: https://www.st.com/resource/en/datasheet/hts221.pdf
PS:
The X-CUBE_MEMS1's Product Page is here: https://www.st.com/en/embedded-software/x-cube-mems1.html