Application Note

Bosch Sensortec

BlueBox Demo-Board for the digital sensors AN18002

SMB365 (acceleration) and SMD500 (pressure)

How to perform a SMB365 Selftest:

Put the BlueBox in a stable neutral-horizontal position

Select Operation Mode (example refers to Normal-Power Mode) [20]

Select acceleration range (example refers to low g Mode) [21]

Scale ordinate [27], [29] and abscissa [30] (example refers to ±512 LSB full scale, in 2g range)

Start data acquisition [8]

Wait a few seconds

Activate Selftest (Selftest On) [24]

Wait a few seconds

Deactivate Selftest (Selftest Off) [24]

Stop data acquisition [9]

Interpret selftest by comparing LSB signals

A successful test shows a rising edge (signal ad on) while activating the Selftest function and a falling edge (signal subtraction) while activating the Selftest function at every axis on the acceleration signal output screen. Dependent on sensor, acceleration range and axis, the test signal should respond a LSB value within the specified tolerance level in a stable neutral- horizontal position of the board.

Acceleration range

Axis

Successful selftest signal

 

 

 

Low g (± 2g)

X and Y

see related sensor datasheet

 

 

Z

see related sensor datasheet

 

 

 

 

High g (± 10g)

X and Y

see related sensor datasheet

 

 

Z

see related sensor datasheet

 

 

 

 

Rev. 1.0

Page 41

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