Proc jsou na I2C pull-down odpory, kdyz klidovy stav I2C je log 1. Vas neucili, jak I2C funguje? V datasheetu navic pisou "Both lines must be connected to Vdd_IO through an external pull-up
resistor. When the bus is free both the lines are high."

Kde je orchranna dioda v napajeni?

Jsou souhlasne osy obou senzoru? 

Neni hrebinek od akcelerometru moc blizko sroubu?