Part Number: TMS320F28335 Tool/software: Code Composer Studio I'm traying to sample a current signal but I have a problem with the sample, the sample frequency is a 12kHz from the ePMW2 and the current signal is 60Hz, the next figure shown the signal sampled and the second figure is of a signal current of 65Hz and the signal of 65 Hz is distorted, I'm using a circular buffer . Could you tell me why is happen?. The code is below. Second Figure void InitAdc(void) { //--- Reset the ADC module AdcRegs.ADCTRL1.bit.RESET = 1; // Reset the ADC // Must wait 2 ADCCLK periods for the reset to take effect. The ADC is // already reset after a DSP reset, but this example is just showing good // coding practice to reset the peripheral before configuring it (as you // never know why the DSP has started the code over again from the // beginning). Assuming a 12.5 MHz ADCCLK was previously configured, and // a 150 MHz SYSCLKOUT, the wait period of 2 ADCCLK periods equates to 24 // CPU clocks. This is the example being used below. asm(" RPT #22 || NOP"); // Must wait for ADC reset to take effect (*ADC_cal_func_ptr)(); //--- Select the ADC reference AdcRegs.ADCREFSEL.bit.REF_SEL = 0; // 0=internal, 1=external //--- Power-up the ADC AdcRegs.ADCTRL3.all = 0x00EC; // Power-up reference and main ADC // bit 15-8 0's: reserved // bit 7-6 11: ADCBGRFDN, reference power, 00=off, 11=on // bit 5 1: ADCPWDN, main ADC power, 0=off, 1=on // bit 4-1 0110: ADCCLKPS, clock prescaler, FCLK=HSPCLK/(2*ADCCLKPS) // bit 0 0: SMODE_SEL, 0=sequential sampling, 1=simultaneous sampling DelayUs(5000); // Wait 5ms before using the ADC //--- Configure the other ADC register AdcRegs.ADCMAXCONV.all = 0xB; // bit 15-7 0's: reserved // bit 6-4 000: MAX_CONV2 value // bit 3-0 0000: MAX_CONV1 value (0 means 1 conversion) // For CPU servicing of ADC, we are only doing 1 conversion in the // sequence. So, we only need to configure the first channel // selection in the sequence. All other channel selection fields // are don't cares in this example. AdcRegs.ADCCHSELSEQ1.bit.CONV00 = 0x0; // Convert Channel 0 AdcRegs.ADCCHSELSEQ1.bit.CONV01 = 0x1; AdcRegs.ADCCHSELSEQ1.bit.CONV02 = 0x2; AdcRegs.ADCCHSELSEQ1.bit.CONV03 = 0x3; AdcRegs.ADCCHSELSEQ2.bit.CONV04 = 0x4; AdcRegs.ADCCHSELSEQ2.bit.CONV05 = 0x5; AdcRegs.ADCCHSELSEQ2.bit.CONV06 = 0x6; AdcRegs.ADCCHSELSEQ2.bit.CONV07 = 0x7; AdcRegs.ADCCHSELSEQ3.bit.CONV08 = 0x8; AdcRegs.ADCCHSELSEQ3.bit.CONV09 = 0x9; AdcRegs.ADCCHSELSEQ3.bit.CONV10 = 0x10; AdcRegs.ADCTRL1.all = 0x0710; // bit 15 0: reserved // bit 14 0: RESET, 0=no action, 1=reset ADC // bit 13-12 00: SUSMOD, 00=ignore emulation suspend // bit 11-8 0111:/1111 ACQ_PS (Acquisition), 0111 = 8 x ADCCLK // bit 7 0: CPS (Core clock), 0: ADCCLK=FCLK/1, 1: ADCCLK=FCLK/2 // bit 6 0: CONT_RUN, 0=start/stop mode, 1=continuous run // bit 5 0: SEQ_OVRD, 0=disabled, 1=enabled // bit 4 1: SEQ_CASC, 0=dual sequencer, 1=cascaded sequencer // bit 3-0 0000: reserved AdcRegs.ADCTRL2.all = 0x0900; // bit 15 0: ePWM_SOCB_SEQ, 0=no action // bit 14 0: /1 RST_SEQ1, 0=no action // bit 13 0: SOC_SEQ1, 0=clear any pending SOCs // bit 12 0: reserved // bit 11 1: INT_ENA_SEQ1, 1=enable interrupt // bit 10 0: INT_MOD_SEQ1, 0=int on every SEQ1 conv // bit 9 0: reserved // bit 8 1: ePWM_SOCA_SEQ1, 1=SEQ1 start from ePWM_SOCA trigger // bit 7 0: EXT_SOC_SEQ1, 1=SEQ1 start from ADCSOC pin // bit 6 0:/1 RST_SEQ2, 0=no action // bit 5 0: SOC_SEQ2, no effect in cascaded mode // bit 4 0: reserved // bit 3 0: /1 INT_ENA_SEQ2, 0=int disabled // bit 2 0: /1 INT_MOD_SEQ2, 0=int on every other SEQ2 conv // bit 1 0: reserved // bit 0 0: ePWM_SOCB_SEQ2, 0=no action //--- Enable the ADC interrupt PieCtrlRegs.PIEIER1.bit.INTx6 = 1; // Enable ADCINT in PIE group 1 IER |= 0x0001; // Enable INT1 in IER to enable PIE group } // end InitAdc() interrupt void ADCINT_ISR(void) // PIE1.6 @ 0x000D4A ADCINT (ADC) { static Uint16 *Current1Ptr = Current1; // Pointer to ADC data buffer static Uint16 *Current2Ptr = Current2; static Uint16 *Current3Ptr = Current3; static Uint16 *Current4Ptr = Current4; static Uint16 *Current5Ptr = Current5; static Uint16 *Voltage_ac1Ptr = Voltage_ac1; static Uint16 *Voltage_ac2Ptr = Voltage_ac2; static Uint16 *Voltage_ac3Ptr = Voltage_ac3; static Uint16 *Voltage_dc1Ptr = Voltage_dc1; static Uint16 *Voltage_dc2Ptr = Voltage_dc2; static Uint16 *temperaturePtr = temperature; static volatile Uint16 GPIO34_count = 0; // Counter for pin toggle PieCtrlRegs.PIEACK.all = PIEACK_GROUP1; // Must acknowledge the PIE group //--- Manage the ADC registers AdcRegs.ADCTRL2.bit.RST_SEQ1 = 1; // Reset SEQ1 to CONV00 state AdcRegs.ADCST.bit.INT_SEQ1_CLR = 1; // Clear ADC SEQ1 interrupt flag AdcRegs.ADCTRL2.bit.RST_SEQ2 = 1; // Reset SEQ2 to CONV08 state AdcRegs.ADCST.bit.INT_SEQ2_CLR = 1; // Clear ADC SEQ2 interrupt flag //--- Read the ADC result *Current1Ptr++= AdcMirror.ADCRESULT0; // Read the result *Current2Ptr++ = AdcMirror.ADCRESULT1; *Current3Ptr++ = AdcMirror.ADCRESULT2; *Current4Ptr++ = AdcMirror.ADCRESULT3; *Current5Ptr++ = AdcMirror.ADCRESULT4; *Voltage_ac1Ptr++ = AdcMirror.ADCRESULT5; *Voltage_ac2Ptr++ = AdcMirror.ADCRESULT6; *Voltage_ac3Ptr++ = AdcMirror.ADCRESULT7; *Voltage_dc1Ptr++ = AdcMirror.ADCRESULT8; *Voltage_dc2Ptr++ = AdcMirror.ADCRESULT9; *temperaturePtr++ = AdcMirror.ADCRESULT10; //--- Brute-force the circular buffer if( Current1Ptr == (Current1 + ADC_BUF_LEN) ) { Current1Ptr = Current1; // Rewind the pointer to the beginning } if( Current2Ptr == (Current2 + ADC_BUF_LEN) ) { Current2Ptr = Current2; } if( Current3Ptr == (Current3 + ADC_BUF_LEN) ) { Current3Ptr = Current3; } if( Current4Ptr == (Current4 + ADC_BUF_LEN) ) { Current4Ptr = Current4; } if( Current5Ptr == (Current5 + ADC_BUF_LEN) ) { Current5Ptr = Current5; } if( Voltage_ac1Ptr == (Voltage_ac1 + ADC_BUF_LEN) ) { Voltage_ac1Ptr = Voltage_ac1; } if( Voltage_ac2Ptr == (Voltage_ac2 + ADC_BUF_LEN) ) { Voltage_ac2Ptr = Voltage_ac2; } if( Voltage_ac3Ptr == (Voltage_ac3 + ADC_BUF_LEN) ) { Voltage_ac3Ptr = Voltage_ac3; } if( Voltage_dc1Ptr == (Voltage_dc1 + ADC_BUF_LEN) ) { Voltage_dc1Ptr = Voltage_dc1; } if( Voltage_dc2Ptr == (Voltage_dc2 + ADC_BUF_LEN) ) { Voltage_dc2Ptr = Voltage_dc2; } if( temperaturePtr == (temperature+10) ) { temperaturePtr = temperature; } } void InitEPwm(void) { //--------------------------------------------------------------------- //--- Must disable the clock to the ePWM modules if you //--- want all ePMW modules synchronized. //--------------------------------------------------------------------- asm(" EALLOW"); // Enable EALLOW protected register access SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0; asm(" EDIS"); // Disable EALLOW protected register access EPwm2Regs.TBCTL.bit.CTRMODE = 0x3; // Disable the timer EPwm2Regs.TBCTL.all =0xC033; // Configure timer control register // bit 15-14 11: FREE/SOFT, 11 = ignore emulation suspend // bit 13 0: PHSDIR, 0 = count down after sync event // bit 12-10 000: CLKDIV, 000 => TBCLK = HSPCLK/1 // bit 9-7 000: HSPCLKDIV, 000 => HSPCLK = SYSCLKOUT/1 // bit 6 0: SWFSYNC, 0 = no software sync produced // bit 5-4 11: SYNCOSEL, 11 = sync-out disabled // bit 3 0: PRDLD, 0 = reload PRD on counter=0 // bit 2 0: PHSEN, 0 = phase control disabled // bit 1-0 11: CTRMODE, 11 = timer stopped (disabled) EPwm2Regs.TBCTR = 0x0000; // Clear timer counter EPwm2Regs.TBPRD = ADC_SAMPLE_PERIOD; // Set timer period //12449 EPwm2Regs.TBPHS.half.TBPHS = 0x0000; // Set timer phase EPwm2Regs.ETPS.all = 0x0100; // Configure SOCA // bit 15-14 00: EPWMxSOCB, read-only // bit 13-12 00: SOCBPRD, don't care // bit 11-10 00: EPWMxSOCA, read-only // bit 9-8 01: SOCAPRD, 01 = generate SOCA on first event // bit 7-4 0000: reserved // bit 3-2 00: INTCNT, don't care // bit 1-0 00: INTPRD, don't care EPwm2Regs.ETSEL.all = 0x0A00; // Enable SOCA to ADC // bit 15 0: SOCBEN, 0 = disable SOCB // bit 14-12 000: SOCBSEL, don't care // bit 11 1: SOCAEN, 1 = enable SOCA // bit 10-8 010: SOCASEL, 010 = SOCA on PRD event // bit 7-4 0000: reserved // bit 3 0: INTEN, 0 = disable interrupt // bit 2-0 000: INTSEL, don't care EPwm2Regs.TBCTL.bit.CTRMODE = 0; // Enable the timer in count up mode //--------------------------------------------------------------------- //--- Enable the clocks to the ePWM module. //--- Note: this should be done after all ePWM modules are configured //--- to ensure synchronization between the ePWM modules. //--------------------------------------------------------------------- asm(" EALLOW"); // Enable EALLOW protected register access SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1; // HSPCLK to ePWM modules enabled asm(" EDIS"); // Disable EALLOW protected register access } // end InitEPwm()
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