Other Parts Discussed in Thread: C2000WARE
Tool/software: Code Composer Studio
Hello Team TI,
I have written a code using examples to read on ADC channel 2 and send that result on DAC 1 using cpu timer interrupt. When I see result in Register, DACVALS shows the results which is updated, however when I connect that pin with DSO, it shows no result. What could be the problem? I have pasted whole code here for your reference with highlights of DAC part.
#include "F28x_Project.h" #include "math.h" #define CPUFREQ_MHZ 100 #define DACA 1 #define DACB 2 #define DACC 3 #define REFERENCE 1 #define dac_num DACA Uint32 fs = 2500000; // Sampling Frequency Hz for ADC //Initialize variables such as time period of PWM and sensed voltage float TBPRD = 999; // Time period (PRD=f_clk/f_pwm)-1 for sawtooth float scaled_Vdc = 0; float Vdc_scalar=8; volatile struct DAC_REGS* DAC_PTR[4] = {0x0,&DacaRegs,&DacbRegs,&DaccRegs}; void ConfigureADC(void); void ConfigureEPWM(void); void SetupADCEpwm(Uint16 channel); interrupt void cpu_timer0_isr(void); float PI_controller(float error); float PI_controller1(float error_1); void configureDAC(Uint16 DACNum); // // Main // void main(void) { InitSysCtrl(); // Initialise system InitGpio(); // Initialise GPIO pins CpuSysRegs.PCLKCR2.bit.EPWM1=1; // enable PWM InitEPwm1Gpio(); // Initialise GPIO pins for ePWM1 DINT; // Disable all CPU interrupts InitPieCtrl(); // Initialize the PIE control registers IER = 0x0000; // Disable CPU interrupts and clear all CPU interrupt flags: IFR = 0x0000; InitPieVectTable(); // Initialize the PIE vector table with pointers to the shell Interrupt Service Routines (ISR). configureDAC(dac_num); // Configure DAC ConfigureADC(); // Configure the ADC and power it up ConfigureEPWM(); // Configure the ePWM SetupADCEpwm(2); // Setup the ADC for ePWM triggered conversions on channel 2 // Initialize the Device Peripherals EALLOW; ClkCfgRegs.PERCLKDIVSEL.bit.EPWMCLKDIV = 1; // EPWM clock prescale divider. Here we divide the 200 MHz sysclk by 2 and set EPWMCLK to 100 MHZ CpuSysRegs.PCLKCR0.bit.TBCLKSYNC =0; // clock sync bit unlock EDIS; EALLOW; CpuSysRegs.PCLKCR0.bit.TBCLKSYNC =1; // clock sync bit lock EDIS; EALLOW; PieVectTable.TIMER0_INT = &cpu_timer0_isr; // Map Cpu Timer0 interrupt function to the PIE vector table EDIS; InitCpuTimers(); // Initialize Cpu Timers ConfigCpuTimer(&CpuTimer0, CPUFREQ_MHZ, 1/2500000); // Configure Cpu Timer0 to interrupt at specified sampling frequency CpuTimer0Regs.TCR.all = 0x4000; // Start Cpu Timer0 IER |= M_INT1; // Enable interrupt PieCtrlRegs.PIEIER1.bit.INTx7 = 1; EINT; // Enable Global interrupt INTM ERTM; // Enable Global real time interrupt DBGM for(;;) { asm (" NOP"); } } void configureDAC(Uint16 DACNum) { EALLOW; DAC_PTR[DACNum]->DACCTL.bit.DACREFSEL = REFERENCE; // To set reference for DACREFSEL DAC_PTR[DACNum]->DACOUTEN.bit.DACOUTEN = 1; // TO power up the buffered DAC DAC_PTR[DACNum]->DACVALS.all = 0; // Shadowed DAC value register DELAY_US(10); // Delay for buffered DAC to power up EDIS; } void ConfigureEPWM(void) { EALLOW; // Assumes ePWM clock is already enabled EPwm2Regs.ETSEL.bit.SOCAEN = 1; // Enable SOC on A group EPwm2Regs.ETSEL.bit.SOCASEL = 3; // Select SOC on up-count EPwm2Regs.ETPS.bit.SOCAPRD = 1; // Generate pulse on 1st event EPwm2Regs.TBPRD = 39; // Set period to 2.5MHz EPwm2Regs.TBCTL.bit.CTRMODE = 00 ; // freeze counter EDIS; } void ConfigureADC(void) { EALLOW; //write configurations AdcaRegs.ADCCTL2.bit.PRESCALE = 0xA; //set ADCCLK divider to /6 AdcSetMode(ADC_ADCA, ADC_RESOLUTION_12BIT, ADC_SIGNALMODE_SINGLE); AdcaRegs.ADCCTL1.bit.INTPULSEPOS = 1; //Set pulse positions to late AdcaRegs.ADCCTL1.bit.ADCPWDNZ = 1; //power up the ADC DELAY_US(1000); //delay for 1ms to allow ADC time to power up EDIS; } // // SetupADCEpwm - Setup ADC EPWM acquisition window // void SetupADCEpwm(Uint16 channel) { Uint16 acqps; acqps = 69; //350ns // //Select the channels to convert and end of conversion flag // EALLOW; AdcaRegs.ADCSOC0CTL.bit.CHSEL = channel; //SOC0 will convert pin A2 //Go through page no. 1411 for these register AdcaRegs.ADCSOC0CTL.bit.ACQPS = acqps; //sample window is 70 SYSCLK cycles AdcaRegs.ADCSOC0CTL.bit.TRIGSEL = 7; //trigger on ePWM1 SOCA/C EDIS; } interrupt void cpu_timer0_isr(void) { scaled_Vdc=((float)AdcaResultRegs.ADCRESULT0)/Vdc_scalar; DAC_PTR[DACA]->DACVALS.all = (unsigned int)((float)scaled_Vdc); DAC_PTR[DACB]->DACVALS.all = (unsigned int) ((float)AdcbResultRegs.ADCRESULT0); PieCtrlRegs.PIEACK.all = PIEACK_GROUP1; // Acknowledge this interrupt to receive more interrupts from group 1 CpuTimer1Regs.TCR.all = 0x0010; // Stop Cpu Timer1 to indicate end of interrupt CpuTimer1Regs.TCR.all = 0x0030; // Reload Cpu Timer1 } // // End of file //
