Please check the following points with your code :
Try to read the Chip ID
Provide the I2C or SPI wave form
Check the register ‘Power Control’ bit in register 0x4B and ‘OP Mode’ bit in register 0x4C after initialization is complete.
Please download and use BMM150 API:
https://github.com/BoschSensortec/BMM150-Sensor-API
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