CONFIGURING ADC IN 2808

Waseem,

Waseem Ahmad said:

HOW  TO SAMPLE SAME ADC INPUT AT DIFFERENT INSTANT .

CAN ANYONE ENLIST THE SEQUENCE FOR SUCH ADC CONFIGURATI

Hi David
I have to sample only one channel. I need four samples of input within a PWM cycle i.e. at t=0, period , at CMPA increasing and decreasing. . triggering event could be epwm timer . I am writing the code which i have written but not working.
Regards
Waseem


AdcRegs.ADCMAXCONV.all = 0x0003;

AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x3; // Setup ADCINA3
AdcRegs.ADCCHSELSEQ1.bit.CONV01 = 0x3; // Setup ADCINA3


AdcRegs.ADCCHSELSEQ2.bit.CONV04 = 0x3; // Setup ADCINA3
AdcRegs.ADCCHSELSEQ2.bit.CONV05 = 0x3; // Setup ADCINA3

AdcRegs.ADCTRL2.bit.EPWM_SOCA_SEQ1 = 1;// Enable SOCA from ePWM to start SEQ1
AdcRegs.ADCTRL2.bit.EPWM_SOCB_SEQ2= 1;// Enable SOCB from ePWM to start SEQ2



// to trigger adc soc on cmpa

EPwm6Regs.ETSEL.bit.SOCAEN = 1; // Enable SOC on A group
EPwm6Regs.ETSEL.bit.SOCASEL = 4; // Select SOC from from CPMA on upcount
EPwm6Regs.ETPS.bit.SOCAPRD = 1; // Generate pulse on 1st event
EPwm6Regs.CMPA.half.CMPA = 3000; // Set compare A value
EPwm6Regs.TBPRD = 5000; // Set period for ePWM1
EPwm6Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;



// to trigger adc soc on zero


EPwm5Regs.ETSEL.bit.SOCAEN = 1; // Enable SOC on A group
EPwm5Regs.ETSEL.bit.SOCASEL =1; // Select on zero
EPwm5Regs.ETPS.bit.SOCAPRD = 1; // Generate pulse on 1st event
EPwm5Regs.TBPRD = 5000; // Set period for ePWM1
EPwm5Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN;


//to trigger adc soc on cmpa decreasing

EPwm6Regs.ETSEL.bit.SOCBEN = 1; // Enable SOC on B group
EPwm6Regs.ETSEL.bit.SOCBSEL = 5; // Select SOC WHEN CCPMA on downcount
EPwm6Regs.ETPS.bit.SOCBPRD = 1;// Generate pulse on 1st event



//to trigger adc soc on period


EPwm5Regs.ETSEL.bit.SOCBEN = 1; // Enable SOC on B group
EPwm5Regs.ETSEL.bit.SOCBSEL = 2; // Select SOC WHEN COUNTER IS period
EPwm5Regs.ETPS.bit.SOCBPRD = 1;// Generate pulse on 1st event


//to trigger generate pwm interupt on zero

EPwm5Regs.ETSEL.bit.INTSEL = ET_CTR_ZERO; // Select INT on Zero event
EPwm5Regs.ETSEL.bit.INTEN = 1; // Enable INT
EPwm5Regs.ETPS.bit.INTPRD = 0x1;







for(;;)
{
asm(" NOP");

}


}


interrupt void epwm5_timer_isr(void)
{


sam_2=AdcRegs.ADCRESULT0; //ADCINA3 reault on cmpa
sam_1=AdcRegs.ADCRESULT1; //ADCINA3 reault on aero
sam_4=AdcRegs.ADCRESULT4; //ADCINA3 reault on cmpa decreasing
sam_3=AdcRegs.ADCRESULT5; //ADCINA3 reault on period

i need to sample same voltage at different instant 

Here is a diagram explaining what i needed to achieve.