CCS/LAUNCHXL-F280049C: f280049C: ADC with Trip zone

How are you detecting ADC = 0? Are you just reading the results and doing the comparison in software? There are a few ways you can do this in hardware that you may want to consider. The ADC has a post-processing block (PPB) that you can use to detect the crossing of a threshold and then send a signal out on the XBAR that could be routed to the PWM trip input.

The CMPSS can be used to do something similar as well. There's a cmpss_ex1_asynch example that demonstrates it in

C2000Ware_x_xx_xx_xx\driverlib\f28004x\examples\cmpss\

Even if you decide you want to use PPB instead of CMPSS, the example should be helpful in figuring out how to configure the XBAR and the PWM trip signals.

Whitney

Hi Whitney,

yes exactly right i get ADC values with reading. i once read the CMPSS code but i didn't understand it exactly and how can i modify this program in my case ?

Regards

Hi Whitney,

i followed your hints, in my code i used the functions of ADC PPB and Trip zone, but my ePWM1 doesn't turn off at Adcresult=0Volt 

//main
void main(void)
{
epwm1TZIntCount = 0U;
Interrupt_register(INT_EPWM1_TZ, &epwm1TZISR);
initTZGPIO();
Device_init();
Device_initGPIO();
Interrupt_enable(INT_EPWM1_TZ);
Interrupt_initModule();
Interrupt_initVectorTable();
Interrupt_register(INT_ADCA1, &adcA1ISR);
initEPWMGPIO();
initEPWM1_Configuration();
SysCtl_disablePeripheral(SYSCTL_PERIPH_CLK_TBCLKSYNC);
initADC();
initEPWM();
initADCSOC();
SysCtl_enablePeripheral(SYSCTL_PERIPH_CLK_TBCLKSYNC);
Interrupt_enable(INT_ADCA1);

EINT;
ERTM;

while(1)
{
EPWM_enableADCTrigger(EPWM8_BASE, EPWM_SOC_A);
EPWM_setTimeBaseCounterMode(EPWM8_BASE, EPWM_COUNTER_MODE_UP);
EPWM_disableADCTrigger(EPWM8_BASE, EPWM_SOC_A);
EPWM_setTimeBaseCounterMode(EPWM8_BASE, EPWM_COUNTER_MODE_STOP_FREEZE);
}
}

__interrupt void epwm1TZISR(void)
{
epwm1TZIntCount++;
// Toggle GPIO to notify when TZ is entered
GPIO_togglePin(25);
// Clear the flags - we will continue to take this interrupt until the TZ
// pin goes high.
EPWM_clearTripZoneFlag(EPWM1_BASE, (EPWM_TZ_INTERRUPT | EPWM_TZ_FLAG_CBC));
Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP2);
}

void initADC(void)
{
ADC_setupPPB(ADCA_BASE, ADC_PPB_NUMBER1, ADC_SOC_NUMBER6);
ADC_enablePPBEvent(ADCA_BASE, ADC_PPB_NUMBER1, ADC_EVT_TRIPLO);
ADC_setPPBReferenceOffset(ADCA_BASE, ADC_PPB_NUMBER1 , 0);
ADC_setPPBTripLimits(ADCA_BASE, ADC_PPB_NUMBER1, 4095, 819);
ADC_setVREF(ADCA_BASE, ADC_REFERENCE_INTERNAL, ADC_REFERENCE_3_3V); 
ADC_setPrescaler(ADCA_BASE, ADC_CLK_DIV_4_0);
ADC_setInterruptPulseMode(ADCA_BASE, ADC_PULSE_END_OF_CONV);
ADC_enableConverter(ADCA_BASE);
DEVICE_DELAY_US(1000);
}
void initEPWM(void)
{
EPWM_disableADCTrigger(EPWM8_BASE, EPWM_SOC_A);
EPWM_setADCTriggerSource(EPWM8_BASE, EPWM_SOC_A, EPWM_SOC_TBCTR_U_CMPA);
EPWM_setADCTriggerEventPrescale(EPWM8_BASE, EPWM_SOC_A, 1);
EPWM_setCounterCompareValue(EPWM8_BASE, EPWM_COUNTER_COMPARE_A, 83);
EPWM_setTimeBasePeriod(EPWM8_BASE, 166); // Frequenz der PWM8 600Khz
EPWM_setTimeBaseCounterMode(EPWM8_BASE, EPWM_COUNTER_MODE_STOP_FREEZE);

}
void initADCSOC(void)
{
ADC_setupSOC(ADCA_BASE, ADC_SOC_NUMBER6, ADC_TRIGGER_EPWM8_SOCA,
ADC_CH_ADCIN6, 10);

ADC_setInterruptSource(ADCA_BASE, ADC_INT_NUMBER1, ADC_SOC_NUMBER6);
ADC_enableInterrupt(ADCA_BASE, ADC_INT_NUMBER1);
ADC_clearInterruptStatus(ADCA_BASE, ADC_INT_NUMBER1);

}
__interrupt void adcA1ISR(void)
{
Ud1 = ADC_readResult(ADCARESULT_BASE, ADC_SOC_NUMBER6); 

dutyCycle =(Ud1*EPWM_TIMER_TBPRD/4095); 
EPWM_setCounterCompareValue(EPWM1_BASE, EPWM_COUNTER_COMPARE_A, dutyCycle); 
EPWM_setCounterCompareValue(EPWM1_BASE, EPWM_COUNTER_COMPARE_B, (EPWM_TIMER_TBPRD-dutyCycle)); 
ADC_clearInterruptStatus(ADCA_BASE, ADC_INT_NUMBER1);
Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP1);
}
void initEPWM1_Configuration(void) 
{
// Enable TZ1 as one cycle-by-cycle trip sources
EPWM_enableTripZoneSignals(EPWM1_BASE, EPWM_TZ_SIGNAL_CBC1);
// Action on TZ1
EPWM_setTripZoneAction(EPWM1_BASE,
EPWM_TZ_ACTION_EVENT_TZA,
EPWM_TZ_ACTION_HIGH);
// Enable TZ interrupt
EPWM_enableTripZoneInterrupt(EPWM1_BASE,
EPWM_TZ_INTERRUPT_CBC);
XBAR_setEPWMMuxConfig(XBAR_TRIP4, XBAR_EPWM_MUX00_ADCAEVT1);
XBAR_enableEPWMMux(XBAR_TRIP4, XBAR_MUX00);
EPWM_setClockPrescaler(EPWM1_BASE,
EPWM_CLOCK_DIVIDER_1,
EPWM_HSCLOCK_DIVIDER_1);
EPWM_setTimeBaseCounterMode(EPWM1_BASE, EPWM_COUNTER_MODE_UP_DOWN);
EPWM_setTimeBaseCounter(EPWM1_BASE, 0);
EPWM_setTimeBasePeriod(EPWM1_BASE, EPWM_TIMER_TBPRD);
EPWM_setPeriodLoadMode(EPWM1_BASE, EPWM_PERIOD_SHADOW_LOAD);
EPWM_setCounterCompareShadowLoadMode(EPWM1_BASE,
EPWM_COUNTER_COMPARE_A,
EPWM_COMP_LOAD_ON_CNTR_ZERO);
EPWM_setCounterCompareShadowLoadMode(EPWM1_BASE,
EPWM_COUNTER_COMPARE_B,
EPWM_COMP_LOAD_ON_CNTR_ZERO);
EPWM_setCounterCompareValue(EPWM1_BASE, EPWM_COUNTER_COMPARE_A, 0);
EPWM_setCounterCompareValue(EPWM1_BASE, EPWM_COUNTER_COMPARE_B, 0);
// Dead-Band for ePWM1A/B
EPWM_setRisingEdgeDeadBandDelayInput(EPWM1_BASE,EPWM_DB_INPUT_EPWMA);
EPWM_setFallingEdgeDeadBandDelayInput(EPWM1_BASE,EPWM_DB_INPUT_EPWMA);
EPWM_setDeadBandDelayPolarity(EPWM1_BASE,EPWM_DB_RED,EPWM_DB_POLARITY_ACTIVE_HIGH);
EPWM_setDeadBandDelayPolarity(EPWM1_BASE, EPWM_DB_FED, EPWM_DB_POLARITY_ACTIVE_LOW);
EPWM_setDeadBandDelayMode(EPWM1_BASE,EPWM_DB_RED,true);
EPWM_setDeadBandDelayMode(EPWM1_BASE, EPWM_DB_FED,true );
EPWM_setDeadBandOutputSwapMode(EPWM1_BASE,EPWM_DB_OUTPUT_A, false);
EPWM_setDeadBandOutputSwapMode(EPWM1_BASE, EPWM_DB_OUTPUT_B, false);
EPWM_setRisingEdgeDelayCount(EPWM1_BASE, Dead_Band_RED);
EPWM_setFallingEdgeDelayCount(EPWM1_BASE, Dead_Band_FED);

EPWM_setActionQualifierAction(EPWM1_BASE,
EPWM_AQ_OUTPUT_A,
EPWM_AQ_OUTPUT_HIGH,
EPWM_AQ_OUTPUT_ON_TIMEBASE_ZERO);
EPWM_setActionQualifierAction(EPWM1_BASE,
EPWM_AQ_OUTPUT_A,
EPWM_AQ_OUTPUT_LOW,
EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
EPWM_setActionQualifierAction(EPWM1_BASE,
EPWM_AQ_OUTPUT_B,
EPWM_AQ_OUTPUT_LOW,
EPWM_AQ_OUTPUT_ON_TIMEBASE_ZERO);
EPWM_setActionQualifierAction(EPWM1_BASE,
EPWM_AQ_OUTPUT_B,
EPWM_AQ_OUTPUT_HIGH,
EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
EPWM_setSyncOutPulseMode(EPWM1_BASE, EPWM_SYNC_OUT_PULSE_ON_COUNTER_ZERO); //Synchronize pulse when counting to zero
}
void initEPWMGPIO(void)
{
GPIO_setPadConfig(0, GPIO_PIN_TYPE_STD);
GPIO_setPinConfig(GPIO_0_EPWM1A);
GPIO_setPadConfig(1, GPIO_PIN_TYPE_STD);
GPIO_setPinConfig(GPIO_1_EPWM1B);
}
void initTZGPIO(void)
{
/* // Set GPIO 58 as as Asynchronous input with pull up enabled
GPIO_setPadConfig(58, GPIO_PIN_TYPE_PULLUP);
GPIO_setPinConfig(GPIO_58_GPIO58);
GPIO_setDirectionMode(58, GPIO_DIR_MODE_IN);
GPIO_setQualificationMode(58, GPIO_QUAL_ASYNC);
// Set GPIO 58 as TZ1 input
XBAR_setInputPin(XBAR_INPUT1, 58);*/
// Configure GPIO 25 as general purpose GPIO for monitoring when the TZ
// Interrupt has been entered
GPIO_setPadConfig(25, GPIO_PIN_TYPE_STD);
GPIO_setPinConfig(GPIO_25_GPIO25);
GPIO_setDirectionMode(25, GPIO_DIR_MODE_OUT);
}

Move your call to Interrupt_register() below the call to Interrupt_initVectorTable(). initVectorTable() writes a default entry to all the vectors, so it'll just overwrite what Interrupt_register does. The fact that you didn't see any issues from this seems to confirm that the trip isn't working though...

Can you compare your configuration of the EPWM to that in cmpss_ex1_asynch? I think the XBAR trip signals come through the digital compare module in the EPWM (see the block diagrams in the EPWM chapter of the device technical reference manual).

Whitney

"Can you compare your configuration of the EPWM to that in cmpss_ex1_asynch? I think the XBAR trip signals come through the digital compare module in the EPWM"

exactly this setting i don't quite understand, the program of cmpss and how i can connect the X-Bar signals to the digital compare, can you please help to do that ?

Regards