Bosch Sensortec BMA456 FAQs

This post will cover several frequently asked questions concerning the BMA456 and similar sensors from Bosch Sensortec.

Does the BMA456 sensor support the tilt, motion, and step count features simultaneously? Or are these features mutually exclusive?

All interrupts are supported simultaneously.

How can you compensate for temperature effects (e.g. TCO) during the manufacturing process on BMAxxx products?

Sometimes the soldering process induces changes in the offset that can be characterized. However, it is possible to perform offset calibration and temperature compensation after soldering the device.

Depending on the target application, using a part that has a lower TCO (e.g BMA456 vs BMA423) is recommended to avoid extra calibration in the manufacturing process.

Why is there occasionally no I2C communication after a system reset? In some cases with the BMAxxx sensors after a system reset from the host processor (MCU or AP), no I2C communication is possible.

If the system is sending a reset command while the I2C communication is still ongoing. Then the slave is waiting for clock falling edge to change the values but the host is already in reset mode. In this case, the SDA line will be locked to GND and only manually release the SDA line can recover from this. To avoid such a problem, reset can only be executed after one complete I2C communication is finished.

All information was provided by Bosch Sensortec’s Forum.