AnsweredAssumed Answered

LIS3DH loosing sensitivity/calibration on power up

Question asked by vjr on Sep 8, 2014
Latest reply on Feb 23, 2015 by odot.thomas
We are using LIS3DHTR in our design. Supply voltage is 3.3v.  
Due to capacitors in our design, it takes some time for the 3.3v supply to drain out completely. So, when we turn off and on the unit, there is a chance that we may turn on the unit  while 3.3v supply rail is still draining out. 
During this, we observed that LIS3DH  lost its sensitivity and reporting close to zero acceleration on all 3 axis. 
Sensor remains in this state until we drain out the supply voltage. 
There is no problem with I2C communication. We receive the data. Control registers are untouched, we verify this by reading all the registers. Sensitivity was set to +/-2G. 

In a good working condition, the first 7 registers (0x00-0x06 reserved space) all reporting all zeros. But, in the other case where the sensor lost the sensitivity , the values are 0xFF, 0x30, 0x0F, 0x00, 0x00, 0x00, 0x00. 

Is there any way to come out of this state through I2C register settings, like soft reset, or reloading calibration values ? 

We tried to use BOOT bit to reload the memory contents, but it didn't help. We have to wait until the power supply is drained out completely. 

Outcomes