LSM9DS1 I2C Write to r/w registers
I have an LSM9DS1 IMU/Magnetometer and I am having difficulty in writing a value to the control registers and reading it back after.
I am using the I2C protocol with my MCU device set up as the master and the LSM9DS1 setup as the slave.
1. I am able to read correctly the WHO_AM_I and WHO_AM_I_M registers.
2. CTRL_REG1_M from the manual when reading this register is expected to return by default 0x10, when I read this register it returns 0x18
3. INT_CFG_M from the manual when reading this register is expected to return by default 0x08, when I read this register it returns 0xE8
4. Writing to CTRL_REG6_XL the value 0x20. When I read it back, I read 0x00.
5. Writing to CTRL_REG1_G the value 0x20. When I read it back, I read 0x00.
6. Writing to CTRL_REG3_G the value 0x80. When I read it back, I read 0x00.
7. Writing to CTRL_REG1_M the value 0x90. When I read it back, I read 0x00.
The schematic how the LSM9DS1 is connected is attached.
Once again I believe the I2C connection is correct since I am able to read the WHO_AM_I and WHO_AM_I_M registers.
1. Is there something special that needs to be done before writing to the control registers?
2. Why do CTRL_REG1_M and INT_CFG_M come out with values that are different from the default values documented in the datasheet of the LSM9DS1?