Cannot send data via i2c to master raspberry pi

Hi Pylon,
yes i modified the variables declaration as:

byte  volatile  command = 0;

byte  volatile  txTable[4];                               //for sending data over I2C
byte  volatile  rxTable[4];                               //for sending data over I2C
bool  volatile  newDataAvailable;

ad some news here! Removing the check on command I get data on raspberry pi. Do you know why? But I get always [0,255,255,255] :confused: but it is a step forward.