I am ADXL345 is connected to ATmega 2560 with SPI (mode 3).I write data to the registers and read the recorded data from all registers. However, in the mode 2g (for example) 10-bit value data (DATAX0<<8 | DATAX1) 511 is always equal in all axes!
What am I doing wrong? The datasheet bad written about initialization ADXL345, but in the simplest case, you must do the following:
//Initialization of ADXL345
ADXL345_SPIWrite_Byte(DATA_FORMAT, 0); //SPI 4-wire
ADXL345_SPIWrite_Byte(POWER_CTL, 0); //ADXL345 is off
ADXL345_SPIWrite_Byte(POWER_CTL, 8); //ADXL345 is measure
ADXL345_SPIWrite_Byte(DATA_FORMAT, 0); //ADXL345 resolution 2g
//Read DATAxx-register of ADXL345
for(y=0; y < 6; y++) ADXL345_Data_Array[y] = ADXL345_SPIRead_Byte(DATAX0 + y);
AxisX += ((signed int)ADXL345_Data_Array[1] << 8) | ADXL345_Data_Array[0];
AxisY += ((signed int)ADXL345_Data_Array[3] << 8) | ADXL345_Data_Array[2];
AxisZ += ((signed int)ADXL345_Data_Array[5] << 8) | ADXL345_Data_Array[4];
After read DATAxx-register AxisX = AxisY = AxisZ = 511!!! (for resolution 2g). If you change the resolution, changes only the order of magnitude, but they are all equal and do not depend on the position of the accelerometer !!!
What am I doing wrong???
