CC2650STK: Could not initialize the sensor

Hi Sushrut,

You actually discovered an error on the Wiki-page: the magnetometer data have offsets 12-17, not 7.12. Thank you!

Then you can calculate the value of each axis like this:

uint16_t movementData[9];

float sensorMpu9250MagConvert(int16_t data)
{
  //-- calculate magnetism, unit uT, range +-4900
  return 1.0 * data;
}

// Read data from the sensor into movementData
// ..... 

// Calculate magnetometer x-axis:
float magX = sensorMpu9250MagConvert(movementData[6]);
float magY = sensorMpu9250MagConvert(movementData[7]);
float magZ = sensorMpu9250MagConvert(movementData[8]);

Hi Joman,

Thank you for your reply.

But I have one more question.

In the sensorMpu9250MagRead(int16_t *data) function of sensor_mpu9250.c i am reading the magnetometer data.

As per the above code what are data[0], data[1] and data[2]. 

I am getting same values all the time. Do i need to take the last 3 digits from all the 3 data ?

Or those 3 data are from x,y,z axes?

Could you please explain this?

Try this code, it has been tested and verified.

/*******************************************************************************
* @fn      magMeasure
*
* @brief   Read and display magnetometer values from the Invensense MPU9250
*          movement processing unit. Assumes that the MPU has been turned on
*          and that the data ready interrupt is used to trigger the readout.
*/
static bool magMeasure(void)
{
    bool success;
    uint8_t status;
    int16_t data[3];
    char buf[64];

    // Read data
    status = SensorMpu9250_magRead(data);
    success = status == MAG_STATUS_OK;
    if (success)
    {
        // Display data
        sprintf(buf,"MAG: %04X %04X %04X  x=%d y=%d z=%d (uT)\n",
                (uint16_t)data[0], (uint16_t)data[1], (uint16_t)data[2],
                data[0], data[1], data[2]);
    }
    else
    {
        if (status == MAG_BYPASS_FAIL)
        {
            SensorMpu9250_magReset();
        }
        sprintf(buf, "M error: %02X", status);
    }
    printLog(buf);

    return success;
}

Hello,

I tried the above code, but I am getting some weird output.

I am not understanding why i am getting 'h' all the time.

Could you kindly look into it.

Thanks,

Sushrut

Hello Jomar,

Now I am able to read the data from the magnetometer. I have disabled all other sensors from sensor tag.

I want to send the value of any one of the axes to the receiver.

For example, as shown in the above picture, I want to send only Y-axis data to the receiver.

Is it possible to mask other two axes data? 

Could you kindly let me know how to mask other 2 axes data and send only one axis value to the receiver through Bluetooth?

Also is this possible to disable accelerometer and gyroscope from the sensor tag? I tried it but could not find any code to disable those sensors.

Thanks,

Sushrut

The magnetometer reports data from all 3 axes, you can't disable them individually. But its is up to your application what data you send to the receiver. In the BLE application the convention is that you fill in with 0 for all the disabled axes. But if the receiving end knows what data to expect it is enough to send, say, the magetornmeter Y-axis. The function that sends data over a BLE link is Movement_setParameter(), invoked in sensortag_mov.c. Here you can pick and chose what to send.