float zero_G = 512.0; //ADC is 0~1023 the zero g output equal to Vs/2
//ADXL335 power supply by Vs 3.3V
Why you use 512 here? and
float scale = 102.3; //ADXL335330 Sensitivity is 330mv/g
//330 * 1024/3.3/1000
How you got this 102.3 value here?
please explain it appropriately