step count and sensor time register

[Gideon]

Dear,

I read out the datasheet of BMA400 for Sensor time.

The resister value of sensor time is described as "After the timer has reached the maximum value, the counter resets to zero."

- Could you tell me the "step count" value resets to zero after the value reached the maximum? for BMA400 and BMI160?

Thanks

[BSTRobin]

Hello Gideon,

It describes sensor time, doesn't have anything to do with step counter.
Sensor has a internal counter that uses a 25.6khz clock source. Its resolution is 21 bits, so it will reach an upper limit when counting all the time. When it reaches the upper limit, it will clear the counter to zero and start counting again. Output is sensor time.

[Gideon]

Hello Robin
doesn't have anything to do with step counter.

It means the step count value stop at upper limit when it reaches upper limit value. it doesn't reset to zero. Am I correct?

thanks

[BSTRobin · Accepted solution]

Hello Gideon,

No.

You confused the two things:
1.Step counter: this counter is for step, not for sensor time. Get values from register STEP_CNT_0(0x15) to STEP_CNT_2(0x17).
2.Sensor time: this counter is for sensor stamp, sensor uses this counter to accumulate time. Get values from register SENSOR_TIME0(0xA) to SENSOR_TIME2(0xC).