ADXL345
Contributed by Alan Carvalho de Assis
The ADXL345 accelerometer can operate in I2C or SPI mode. To operate in I2C mode just connect the CS pin to Vddi/o.
In order to operate in SPI mode CS need to use connected to microcontroller, it cannot leave unconnected.
In SPI mode it works with clock polarity (CPOL) = 1 and clock phase (CPHA) = 1.