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MMA8451 OUT_Z_MSB freeze !

Question asked by Gaétan Philbiche on Mar 22, 2017

Hi,

 

I have make a board with MMA8451, in some board 4% of the first production (200 pcs).

Sometimes the OUT_Z_MSB value stay bloqued to 0x0f, all other value are ok.

When OUT_Z_MSB freeze, the orientation interrupt don't work.

 

If I try to shock the board, on Y axis the MMA8451 run correctly for few time, but after few minutes, the MMA8451 stay again in the bloqued mode with OUT_Z_MSB = 0x0F. (value is always 0x0F)

 

If I poweroff all the device, the MMA8451 stay in same state that is before the poweroff. If bloqued before poweroff, the MMA8451 stay bloqued after the restart.

 

Please see some register capture:

 

0xff, 0xee, 0xe0, 0x35, 0x58, 0xf, 0x20, 0x0, 0x0, 0x0, 0x0, 0x2, 0x10, 0x1a, 0x0, 0x0, 0x82, 0x40, 0x0, 0x44, 0x84, 0x0 <repeats 21 times>, 0x6d, 0x1f, 0x21, 0x10, 0xfd, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0

0xff, 0xc1, 0xe8, 0xef, 0xd0, 0xf, 0x28, 0x0, 0x0, 0x0, 0x0, 0x2, 0x10, 0x1a, 0x0, 0x0, 0x86, 0x40, 0x0, 0x44, 0x84, 0x0 <repeats 21 times>, 0x6d, 0x1f, 0x21, 0x10, 0xfd, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0

0xff, 0x27, 0x70, 0xdd, 0xb0, 0xf, 0x28, 0x0, 0x0, 0x0, 0x0, 0x2, 0x10, 0x1a, 0x0, 0x0, 0x84, 0x40, 0x0, 0x44, 0x84, 0x0 <repeats 21 times>, 0x6d, 0x1f, 0x21, 0x10, 0xfd, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0

0xff, 0xc0, 0xd8, 0x6, 0xa8, 0xf, 0x18, 0x0, 0x0, 0x0, 0x0, 0x2, 0x10, 0x1a, 0x0, 0x0, 0x86, 0x40, 0x0, 0x44, 0x84, 0x0 <repeats 21 times>, 0x6d, 0x1f, 0x21, 0x10, 0xfd, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0

 

BAFRO in PL_STATUS never go to 1

 

After a big shoxk on Y axis:

0xff, 0x11, 0x50, 0x2a, 0x90, 0xce, 0xc8, 0x0, 0x0, 0x0, 0x0, 0x2, 0x10, 0x1a, 0x0, 0x0, 0x83, 0x40, 0x0, 0x44, 0x84, 0x0 <repeats 21 times>, 0x6d, 0x1f, 0x21, 0x10, 0xfd, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0

 

All work fine !

 

Please can you help me to clear this problem ?

 

Regards

Gaétan

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