I'm facing issues in full-wave converters, where the ADC initialization file has been attached. The ADC ISR is triggered at first instant from ePWM used for switching at 20 kHz. The value which I have measured by averaging as shown below doesn't show linear variation with multimeter for 0 to 100 % output.
ADC ISR:
//========================================
volatile Uint16 read_adc ;
Uint32 buf_read_adc = 0 ;
Uint16 count_avg=0;
float dc_avg =0;
//========================================
read_adc = AdcResult.ADCRESULT8;
//========================================
buf_read_adc += read_adc ;
count_avg++;
if(count_avg > 100)
{
dc_avg = ((float)buf_read_adc ) / (count_avg* conversion_factor);
buf_read_adc = 0;
count_avg = 0;
}
//========================================
Please can I get expert advice on how to improve the measurement techniques of signal switched at high frequency ripple and having 3 phase (50 Hz) rectified ripple.
I using ADC ISR at the same rate as switching i.e. ePWM. Should ADC ISR have higher frequency?
Please suggest me improvements and implementation techniques in ISR timings/ ADC initializations/ ADC measurement improvements or software filter.
I also read floating values at ADC pins even if the ADC isn't having any voltage at its pins.
AdcRegs.ADCCTL1.all = 0x00E4;
AdcRegs.ADCCTL2.all = 0x0001;
DELAY_US(1000);
AdcRegs.ADCSAMPLEMODE.bit.SIMULEN0 = 0;
AdcRegs.ADCSAMPLEMODE.bit.SIMULEN2 = 0;
AdcRegs.ADCSAMPLEMODE.bit.SIMULEN4= 0;
AdcRegs.ADCSAMPLEMODE.bit.SIMULEN6= 0;
AdcRegs.ADCSAMPLEMODE.bit.SIMULEN8 = 0;
AdcRegs.ADCSAMPLEMODE.bit.SIMULEN10 = 0;
AdcRegs.ADCSAMPLEMODE.bit.SIMULEN12 = 0;
AdcRegs.ADCSAMPLEMODE.bit.SIMULEN14 = 0;
AdcRegs.ADCSOC0CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC1CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC2CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC3CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC4CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC5CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC6CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC7CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC8CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC9CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC10CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC11CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC12CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC13CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC14CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC15CTL.bit.TRIGSEL = 5;
AdcRegs.ADCSOC0CTL.bit.CHSEL = 0x0;
AdcRegs.ADCSOC1CTL.bit.CHSEL = 0x1;
AdcRegs.ADCSOC2CTL.bit.CHSEL = 0x2;
AdcRegs.ADCSOC3CTL.bit.CHSEL = 0x3;
AdcRegs.ADCSOC4CTL.bit.CHSEL = 0x4;
AdcRegs.ADCSOC5CTL.bit.CHSEL = 0x5;
AdcRegs.ADCSOC6CTL.bit.CHSEL = 0x6;
AdcRegs.ADCSOC7CTL.bit.CHSEL = 0x7;
AdcRegs.ADCSOC8CTL.bit.CHSEL = 0x8;
AdcRegs.ADCSOC9CTL.bit.CHSEL = 0x9;
AdcRegs.ADCSOC10CTL.bit.CHSEL = 0xA;
AdcRegs.ADCSOC11CTL.bit.CHSEL = 0xB;
AdcRegs.ADCSOC12CTL.bit.CHSEL = 0xC;
AdcRegs.ADCSOC13CTL.bit.CHSEL = 0xD;
AdcRegs.ADCSOC14CTL.bit.CHSEL = 0xE;
AdcRegs.ADCSOC15CTL.bit.CHSEL = 0xF;
AdcRegs.ADCSOC0CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC1CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC2CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC3CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC4CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC5CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC6CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC7CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC8CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC9CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC10CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC11CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC12CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC13CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC14CTL.bit.ACQPS = 9;
AdcRegs.ADCSOC15CTL.bit.ACQPS = 9;
AdcRegs.ADCINTSOCSEL1.bit.SOC0 = 0;
AdcRegs.SOCPRICTL.bit.SOCPRIORITY = 0;
AdcRegs.INTSEL1N2.bit.INT1CONT = 0;
AdcRegs.INTSEL1N2.bit.INT1E = 1;
AdcRegs.INTSEL1N2.bit.INT1SEL = 15;
PieCtrlRegs.PIEIER1.bit.INTx1 = 1;
IER |= 0x0001;
AdcRegs.ADCCTL1.bit.ADCENABLE = 1;
asm(" EDIS");
