About Myzhar

Hi o_o, the Z2 value to zero is a possible value, but in the "compensate_z" function it is checked and generates a `BMM150_OVERFLOW_OUTPUT` error. This is the function I'm referring to: /*! * @brief This internal API is used to obtain the compensated * magnetometer Z axis data(micro-tesla) in int16_t. */ int16_t compensate_z(int16_t mag_data_z, uint16_t data_rhall, const struct bmm150_dev *dev) { int32_t retval; int16_t process_comp_z0; int32_t process_comp_z1; int32_t process_comp_z2; int32_t process_comp_z3; int16_t process_comp_z4; if (mag_data_z != BMM150_ZAXIS_HALL_OVERFLOW_ADCVAL) { if ((dev->trim_data.dig_z2 != 0) && (dev->trim_data.dig_z1 != 0) && (data_rhall != 0) && (dev->trim_data.dig_xyz1 != 0)) { /*Processing compensation equations*/ process_comp_z0 = ((int16_t)data_rhall) - ((int16_t) dev->trim_data.dig_xyz1); process_comp_z1 = (((int32_t)dev->trim_data.dig_z3) * ((int32_t)(process_comp_z0))) / 4; process_comp_z2 = (((int32_t)(mag_data_z - dev->trim_data.dig_z4)) * 32768); process_comp_z3 = ((int32_t)dev->trim_data.dig_z1) * (((int16_t)data_rhall) * 2); process_comp_z4 = (int16_t)((process_comp_z3 + (32768)) / 65536); retval = ((process_comp_z2 - process_comp_z1) / (dev->trim_data.dig_z2 + process_comp_z4)); /* saturate result to +/- 2 micro-tesla */ if (retval > BMM150_POSITIVE_SATURATION_Z) { retval = BMM150_POSITIVE_SATURATION_Z; } else { if (retval < BMM150_NEGATIVE_SATURATION_Z) retval = BMM150_NEGATIVE_SATURATION_Z; } /* Conversion of LSB to micro-tesla*/ retval = retval / 16; } else { retval = BMM150_OVERFLOW_OUTPUT; } } else { /* Overflow condition*/ retval = BMM150_OVERFLOW_OUTPUT; } return (int16_t)retval; } ... View more

We finally found the problem using X-Ray: a simply short circuit under the sensor due to a wrong way of placing the soldering paste. Now the sensors seems to work correctly, even if the Z axis is showing a very low working range, but I expect to solve this with hard and soft iron calibration. ... View more

This is scaring since the PCB I'm using comes from production manufacturer, but it could explain a lot of things. Does a chip damage explain also the zero value for Z2 trim data? ... View more

I just noticed, debugging the Bosh API, that the function `compensate_z` always returns `BMM150_OVERFLOW_OUTPUT` because `trim_data.dig_z2` is zero... How can this be possible? Does this mean that the initial trimming has failed? Furthermore performing a self test after initialization I get the following errors: Normal test: `BMM150_W_NORMAL_SELF_TEST_XZ_FAIL` Advanced test: `BMM150_W_ADV_SELF_TEST_FAIL` Thank you Walter ... View more

The sensor is connected to BMI270 as auxiliar I2C device. This is my initialization code: int8_t BMM150_DEVICE_Init() { systemStatus.bmm150_init_count++; int8_t rslt = BMM150_OK; // ----> BMM150 initialization over I2C (BMI270 aux) bmm150_dev.dev_id = BMM150_DEFAULT_I2C_ADDRESS; bmm150_dev.intf = BMM150_I2C_INTF; bmm150_dev.read = bmm150_read; bmm150_dev.write = bmm150_write; bmm150_dev.delay_ms = bmm150_delay_ms; rslt = bmm150_init(&bmm150_dev); if(rslt!=BMM150_OK) { goto exit; } // <---- BMM150 initialization over I2C (BMI270 aux) // ----> Configuration bmm150_dev.settings.preset_mode = BMM150_PRESETMODE_REGULAR; rslt = bmm150_set_presetmode(&bmm150_dev); if(rslt!=BMM150_OK) { goto exit; } bmm150_dev.settings.pwr_mode = BMM150_NORMAL_MODE; rslt = bmm150_set_op_mode(&bmm150_dev); // <---- Configuration exit: if( rslt == BMM150_OK ) { systemStatus.bmm150_initialized = 1; } else { systemStatus.bmm150_initialized = 0; } return rslt; }   One of the weird thing that I noticed is that after putting a neodymium magnet near the sensor it started working like if there was something "blocked". ... View more