Sample code is available on the Arm Mbed OS platform.
I2C interface sample code can be found at the following link:
https://os.mbed.com/users/ddelsuc/code/RM3100BB_Sample_Code/
SPI interface sample code can be found at the following link:
https://os.mbed.com/users/BeiZhang/code/RM3100_SPI_SampleCode/
Sample code is also available for Arduino platform.
The sample code for both SPI and I2C interface can be found at the following link:
https://github.com/hnguy169/RM3100-Arduino
Click https://www.pnicorp.com/rm3100/ for RM3100 user manual.