Reference

Library

• Arduino Library: DFRobot_BMM150_library (installation guide: How to install the library?)
• Python Library: Download via git clone https://github.com/DFRobot/DFRobot_BMM150 (for Raspberry Pi).

Communication Protocol Description

Connections for different communications

• I2C: the default address is 0x13

Note: When using magDrdyInterrupt, connect pin DRDY to the related interrupt pin of mainboard instead of the pin INT.

• Connection for SPI

Note: Pin PS should be connected to GND for SPI connection.

• Interrupt Pin Connection

API Description

  /**
   * @fn softReset
   * @brief Soft reset, restore to suspended mode after soft reset and then enter sleep mode, soft reset can't be implemented under suspend mode
   */
  void softReset(void);

  /**
   * @fn setOperationMode
   * @brief Set sensor operation mode
   * @param opMode mode
   * @n BMM150_POWERMODE_NORMAL      normal mode  Get geomagnetic data normally
   * @n BMM150_POWERMODE_FORCED      forced mode  Single measurement, the sensor restores to sleep mode when the measurement is done.
   * @n BMM150_POWERMODE_SLEEP       sleep mode   Users can visit all the registers, but can’t measure geomagnetic data
   * @n BMM150_POWERMODE_SUSPEND     suspend mode At the time the sensor cpu doesn’t work and can’t implement any operation. Users can only visit the content of the control register BMM150_REG_POWER_CONTROL
   */
  void setOperationMode(uint8_t opMode);

  /**
   * @fn getOperationMode
   * @brief Get sensor operation mode
   * @return result Return sensor operation mode as a character string
   */
  String getOperationMode(void);

  /**
   * @fn setPresetMode
   * @brief Set preset mode, make it easier for users to configure sensor to get geomagnetic data 
   * @param presetMode
   * @n BMM150_PRESETMODE_LOWPOWER       Low power mode, get a fraction of data and take the mean value.
   * @n BMM150_PRESETMODE_REGULAR        Regular mode, get a number of data and take the mean value.
   * @n BMM150_PRESETMODE_ENHANCED       Enhanced mode, get a plenty of data and take the mean value.
   * @n BMM150_PRESETMODE_HIGHACCURACY   High accuracy mode, get a huge number of data and take the mean value.
   */
  void setPresetMode(uint8_t presetMode);

  /**
   * @fn setRate
   * @brief Set the rate of obtaining geomagnetic data, the higher, the faster (without delay function)
   * @param rate
   * @n BMM150_DATA_RATE_02HZ
   * @n BMM150_DATA_RATE_06HZ
   * @n BMM150_DATA_RATE_08HZ
   * @n BMM150_DATA_RATE_10HZ  (default rate)
   * @n BMM150_DATA_RATE_15HZ
   * @n BMM150_DATA_RATE_20HZ
   * @n BMM150_DATA_RATE_25HZ
   * @n BMM150_DATA_RATE_30HZ
   */
  void setRate(uint8_t rate);

  /**
   * @fn getRate
   * @brief Get the config data rate, unit: HZ
   * @return rate
   */
  uint8_t getRate(void);

  /**
   * @fn getGeomagneticData
   * @brief Get the geomagnetic data of 3 axis (x, y, z)
   * @return Geomagnetic data structure, unit: (uT)
   */
  sBmm150MagData_t getGeomagneticData(void);

  /**
   * @fn getCompassDegree
   * @brief Get compass degree
   * @return Compass degree (0° - 360°)
   * @n      0° = North, 90° = East, 180° = South, 270° = West.
   */
  float getCompassDegree(void);

  /**
   * @fn setDataReadyPin
   * @brief Enable or disable data ready interrupt pin
   * @n After enabling, the DRDY pin jump when there's data coming.
   * @n After disabling, the DRDY pin will not jump when there's data coming.
   * @n High polarity: active on high, the default is low level, which turns to high level when the interrupt is triggered.
   * @n Low polarity: active on low, default is high level, which turns to low level when the interrupt is triggered.
   * @param modes
   * @n     DRDY_ENABLE        Enable DRDY
   * @n     DRDY_DISABLE       Disable DRDY
   * @param polarity
   * @n     POLARITY_HIGH      High polarity
   * @n     POLARITY_LOW       Low polarity
   */
  void setDataReadyPin(uint8_t modes, uint8_t polarity=POLARITY_HIGH);

  /**
   * @fn getDataReadyState
   * @brief Get the data ready status, determine whether the data is ready
   * @return status
   * @n true  Data ready
   * @n false Data is not ready
   */
  bool getDataReadyState(void);

  /**
   * @fn setMeasurementXYZ
   * @brief Enable the measurement at x-axis, y-axis and z-axis, default to be enabled. After disabling, the geomagnetic data at x, y, and z axis are wrong.
   * @param channelX
   * @n   MEASUREMENT_X_ENABLE        Enable the measurement at x-axis
   * @n   MEASUREMENT_X_DISABLE       Disable the measurement at x-axis
   * @param channelY
   * @n   MEASUREMENT_Y_ENABLE        Enable the measurement at y-axis
   * @n   MEASUREMENT_Y_DISABLE       Disable the measurement at y-axis
   * @param channelZ
   * @n   MEASUREMENT_Z_ENABLE        Enable the measurement at z-axis
   * @n   MEASUREMENT_Z_DISABLE       Disable the measurement at z-axis
   */
  void setMeasurementXYZ(uint8_t channelX = MEASUREMENT_X_ENABLE, uint8_t channelY = MEASUREMENT_Y_ENABLE, uint8_t channelZ = MEASUREMENT_Z_ENABLE);

  /**
   * @fn getMeasurementStateXYZ
   * @brief Get the enabling status at x-axis, y-axis and z-axis
   * @return result Return enabling status as a character string
   */
  String getMeasurementStateXYZ(void);

  /**
   * @fn setThresholdInterrupt(uint8_t modes, int8_t threshold, uint8_t polarity)
   * @brief Set threshold interrupt, an interrupt is triggered when the geomagnetic value of a channel is beyond/below the threshold
   * @n      High polarity: active on high level, the default is low level, which turns to high level when the interrupt is triggered.
   * @n      Low polarity: active on low level, the default is high level, which turns to low level when the interrupt is triggered.
   * @param modes
   * @n     LOW_THRESHOLD_INTERRUPT       Low threshold interrupt mode
   * @n     HIGH_THRESHOLD_INTERRUPT      High threshold interrupt mode
   * @param  threshold
   * @n     Threshold, default to expand 16 times, for example: under low threshold mode, if the threshold is set to be 1, actually the geomagnetic data below 16 will trigger an interrupt
   * @param polarity
   * @n     POLARITY_HIGH      High polarity
   * @n     POLARITY_LOW       Low polarity
   */
  void setThresholdInterrupt(uint8_t modes, int8_t threshold, uint8_t polarity);

  /**
   * @fn setThresholdInterrupt(uint8_t modes, uint8_t channelX, uint8_t channelY, uint8_t channelZ, int8_t threshold, uint8_t polarity)
   * @brief Set threshold interrupt, an interrupt is triggered when the geomagnetic value of a channel is beyond/below the threshold
   * @n   When an interrupt occurs, INT pin level will jump
   * @n   High polarity: active on high level, the default is low level, which turns to high level when the interrupt is triggered.
   * @n   Low polarity: active on low level, the default is high level, which turns to low level when the interrupt is triggered.
   * @param modes
   * @n   LOW_THRESHOLD_INTERRUPT   Low threshold interrupt mode
   * @n   HIGH_THRESHOLD_INTERRUPT  High threshold interrupt mode
   * @param channelX
   * @n   INTERRUPT_X_ENABLE        Enable high threshold interrupt at x-axis
   * @n   INTERRUPT_X_DISABLE       Disable high threshold interrupt at x-axis
   * @param channelY
   * @n   INTERRUPT_Y_ENABLE         Enable high threshold interrupt at y-axis
   * @n   INTERRUPT_Y_DISABLE        Disable high threshold interrupt at y-axis
   * @param channelZ
   * @n   INTERRUPT_Z_ENABLE         Enable high threshold interrupt at z-axis
   * @n   INTERRUPT_Z_DISABLE        Disable high threshold interrupt at z-axis
   * @param  threshold
   * @n   Threshold, default to expand 16 times, for example: if the threshold is set to be 1, actually the geomagnetic data below 16 will trigger an interrupt
   * @param polarity
   * @n     POLARITY_HIGH      High polarity
   * @n     POLARITY_LOW       Low polarity
   */
  void setThresholdInterrupt(uint8_t modes, uint8_t channelX, uint8_t channelY, uint8_t channelZ, int8_t threshold, uint8_t polarity);

  /**
   * @fn getThresholdData
   * @brief Get the data with threshold interrupt occurred
   * @return Returns the structure for storing geomagnetic data, the structure stores the data of 3 axis and interrupt status,
   * @n The interrupt is not triggered when the data at x-axis, y-axis and z-axis are NO_DATA
   * @n String state The storage state is binary data string
   * @n uint8_t value The storage state is binary raw value, the data format are as follows:
   * @n bit0 is 1 Indicate the interrupt occur at x-axis
   * @n bit1 is 1 Indicate the interrupt occur at y-axis
   * @n bit2 is 1 Indicate the interrupt occur at z-axis
   * @n ------------------------------------
   * @n | bit7 ~ bit3 | bit2 | bit1 | bit0 |
   * @n ------------------------------------
   * @n |  reserved   |  0   |  0   |  0   |
   * @n ------------------------------------
   */
  sBmm150ThresholdData_t getThresholdData(void);

  /**
   * @fn selfTest
   * @brief The sensor self test, the returned value indicate the self test result.
   * @param testMode:
   * @n    BMM150_SELF_TEST_NORMAL               Normal self test, test whether x-axis, y-axis and z-axis are connected or short-circuited
   * @n    BMM150_SELF_TEST_ADVANCED             Advanced self test, test the data accuracy at z-axis
   * @return result The returned character string is the self test result
   */
  String selfTest(uint8_t testMode);