TMS320f28335: ADC calibration

I am working on the Vector control of Induction motor. where two signals from LEM current sensor are fed to the adc channel using a level shifter whic ranges the output value compatible with 28335 board i.e (0 to 3 volts). so after calibration at the ADC output I am also reading the value from 0 to 3 volts. But I need both positive and negative values of magnitude for further calculations. can anyone help me in this

[Zorig Abdelmalik]

Hi, You can make a shift for signal before send it to the Dsp. Ex: input interval is -3V 3V so by shifting it will be 0,3V then the real 'Vr' value can be calculated as: Vr=( vi*2 )+3.