The I2C address of the MPU9250 is selectable (between 0x68 AD0 line LOW, and 0x69 AD0 line HIGH), so to use 10 sensors over I2C you could do the following:
- Connect the AD0 pin on each sensor to a Raspberry Pi GPIO digital output pin.
- By default have all GPIO pins set to output LOW
- When you want to read a particular sensor:
- Set the GPIO pin for that sensor to HIGH
- Communicate with that sensor on address 0x69 (all others are on address 0x68 so ignore the commands)
Of course, this will 'cost' you 10 GPIO pins.
Also, don't forget to set that sensors GPIO pin to LOW when you are finished with it (temporarily).