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.
Glad you found your issue. If the part has been short-circuited, I cannot guarantee that will work with full performance, and would advise to replace it to be on the safe side.
On the topic of compensation formula, I will double-check to confirm whether zero is a possible value, and therefore a bug in the API.
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The normal self-test is a continuity check. If indeed the normal self-test has failed, the most likely cause is damage to the sensor. The sensing elements are very close to the edge of the package, and using metal tweezers can chip the silicon and cut the sensing coil. o_o
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I appreciate you sharing you concerns over the BNO055 and let me reassure you that the part is still current and recommended for new designs. We are actually looking forward to bring new features on the BNO055 with firmware update, which is taking a bit longer than expected.
Let me answers your questions:
So is this problem with a specific batch of chips or all the new chips have similar problem? Because earlier in this thread I could see the other bosch team could achieve 40uA power consumption in suspend mode on the BNO055 shuttle board. And is there any kind of workaround or firmware upgrade which can fix this issue?
We have faced similar issue in the past (~160uA using our application board). In our case, it was not related to a specific batch of chips or firmware, but rather an issue with the host MCU. The GPIO pins have internal pull-down which causes extra current consumption. This is why, in the screenshot that Alan shared, multimeter is connected to the GND pin. (GNDIO and GND pin are tied together on the shuttleboard). We have confirmed the MCU pull-down current to be the issue on our end with a custom firmware disabling the pull-down.
[...]if you have any alternative please suggest.
If power consumption is a concern, BNO055 would not be my recommendation. The minimum voltage is 2.5V, and current consumption is 12mA, making it an ~30mW solution for a 9DOF rotation vector. The BHI160 + BMM150 solution operating voltage is 1.8V and current consumption is 1.55mA, making it ~2.8mW solution, about 1/10th of the power used by BNO055. The sensor hub does not contain flash however, which requires a more complicated driver on the host side and increases boot time, but the gains in power consumption are very significant.
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