Hi Team,
My customer is trying to use two ECAP modules for capturing two signals and they were able to capture signals. Now, they want to find
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Hi Team,
My customer is trying to use two ECAP modules for capturing two signals and they were able to capture signals. Now, they want to findthe phase difference between the two signals. Is the ECAP using the same counter for each? Is it possible? If yest, they want to want to know how to do it.
Thank you.
Regards,
May
Is the ECAP using the same counter for each?
No, but they use the same system clock input so using two ECAPs with the same counter configuration will count in step.
how to do it
After synchronizing two or more ECAPs via the SYNCIN signal, the difference between the capture value of the ECAPs will be proportional to the phase difference.
Hi Team,
Customer configured the synchronous selection registers for both ECAP are as follows.
But still they were not able to find the correct phase difference.
ECap1Regs.ECCTL2.bit.SYNCO_SEL = 1;
ECap1Regs.ECCTL2.bit.SYNCI_EN = 0;
ECap1Regs.ECCTL2.bit.SWSYNC = 1;
ECap2Regs.ECCTL2.bit.SYNCO_SEL = 2;
ECap2Regs.ECCTL2.bit.SYNCI_EN = 1;
Thank you.
Regards,
May
Hi Santosh,
Please see code below.
//########################################################################### // // FILE: Example_2833xEPwmUpAQ.c // // TITLE: ePWM Action Qualifier Module using Upcount mode Example // //! \addtogroup f2833x_example_list //! <h1>ePWM Action Qualifier Module using Upcount mode (epwm_up_aq)</h1> //! //! This example configures ePWM1, ePWM2, ePWM3 to produce a waveform with //! independent modulation on EPWMxA and EPWMxB. The compare values CMPA //! and CMPB are modified within the ePWM's ISR. The TB counter is in upmode. //! //! Monitor the ePWM1 - ePWM3 pins on an oscilloscope. //! //! \b External \b Connections \n //! - EPWM1A is on GPIO0 //! - EPWM1B is on GPIO1 //! - EPWM2A is on GPIO2 //! - EPWM2B is on GPIO3 //! - EPWM3A is on GPIO4 //! - EPWM3B is on GPIO5 // //########################################################################### // $TI Release: F2833x Support Library v2.00.00.00 $ // $Release Date: Tue Jun 26 03:14:14 CDT 2018 $ // $Copyright: // Copyright (C) 2009-2018 Texas Instruments Incorporated - http://www.ti.com/ // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions // are met: // // Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // // Redistributions in binary form must reproduce the above copyright // notice, this list of conditions and the following disclaimer in the // documentation and/or other materials provided with the // distribution. // // Neither the name of Texas Instruments Incorporated nor the names of // its contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // $ //########################################################################### // // Included Files // #include "DSP28x_Project.h" // Device Headerfile and Examples Include File void InitEPwm1Example(void); void Gpio_setup1(void); void InitECapture(void); __interrupt void ecap1_isr(void); __interrupt void ecap2_isr(void); Uint32 TSt1, TSt2, TSt3, TSt4; Uint32 Period1, DutyOnTime1, DutyOffTime1; Uint32 TSt11, TSt21, TSt31, TSt41, theta; Uint32 Period11, DutyOnTime11, DutyOffTime11; Uint16 tbpr=750,phs=750/2; void main(void) { // Step 1. Initialize System Control: // PLL, WatchDog, enable Peripheral Clocks // This example function is found in the DSP2833x_SysCtrl.c file. InitSysCtrl(); // Step 2. Initialize GPIO: // This example function is found in the DSP2833x_Gpio.c file and // illustrates how to set the GPIO to it's default state. // InitGpio(); // Skipped for this example Gpio_setup1(); InitEPwm1Example(); InitECap(); InitECapture(); // Step 3. Clear all interrupts and initialize PIE vector table: // Disable CPU interrupts DINT; // Initialize the PIE control registers to their default state. // The default state is all PIE interrupts disabled and flags // are cleared. // This function is found in the DSP2833x_PieCtrl.c file. InitPieCtrl(); // Disable CPU interrupts and clear all CPU interrupt flags: IER = 0x0000; IFR = 0x0000; // Initialize the PIE vector table with pointers to the shell Interrupt // Service Routines (ISR). // This will populate the entire table, even if the interrupt // is not used in this example. This is useful for debug purposes. // The shell ISR routines are found in DSP2833x_DefaultIsr.c. // This function is found in DSP2833x_PieVect.c. InitPieVectTable(); // Interrupts that are used in this example are re-mapped to // ISR functions found within this file. EALLOW; // This is needed to write to EALLOW protected registers PieVectTable.ECAP1_INT = &ecap1_isr; PieVectTable.ECAP2_INT= &ecap2_isr; EDIS; // This is needed to disable write to EALLOW protected registers // Step 4. Initialize all the Device Peripherals: // This function is found in DSP2833x_InitPeripherals.c // InitPeripherals(); // Not required for this example // InitEPwmTimer(); // For this example, only initialize the ePWM Timers // InitECapture(); // Step 5. User specific code, enable interrupts: // Initialize counters: // Enable CPU INT4 which is connected to ECAP1-4 INT: IER |= M_INT4; // Enable eCAP INTn in the PIE: Group 3 interrupt 1-6 PieCtrlRegs.PIEIER4.bit.INTx1 = 1; PieCtrlRegs.PIEIER4.bit.INTx2 = 1; // Enable global Interrupts and higher priority real-time debug events: EINT; // Enable Global interrupt INTM ERTM; // Enable Global realtime interrupt DBGM // Step 6. IDLE loop. Just sit and loop forever (optional): for(;;) { __asm(" NOP"); } } // // epwm1_isr - // // void Gpio_setup1(void){ EALLOW; GpioCtrlRegs.GPAPUD.bit.GPIO0 = 0; // Enable pullup on GPIO0 GpioCtrlRegs.GPAPUD.bit.GPIO1 = 0; // Enable pullup on GPIO1 GpioCtrlRegs.GPAMUX1.bit.GPIO0 = 1; // GPIO0 = PWM1A GpioCtrlRegs.GPAMUX1.bit.GPIO1 = 1; // GPIO1 = PWM1B GpioCtrlRegs.GPAMUX1.bit.GPIO2 = 1; // GPIO1 = PWM2A GpioCtrlRegs.GPAMUX1.bit.GPIO3 = 1; // GPIO1 = PWM2B GpioCtrlRegs.GPAMUX2.bit.GPIO24=1; // GPIO24= ECAP1; GpioCtrlRegs.GPADIR.bit.GPIO25=0; GpioCtrlRegs.GPAMUX2.bit.GPIO25=1; // GPIO24= ECAP2; EDIS; } void InitEPwm1Example() { // // Setup TBCLK // EPwm1Regs.TBCTL.bit.CTRMODE = 2; // Count up down EPwm1Regs.TBPRD = tbpr; // Set timer period EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Disable phase loading EPwm1Regs.TBPHS.half.TBPHS = 0x0000; // Phase is 0 EPwm1Regs.TBCTR = 0x0000; // Clear counter EPwm1Regs.TBCTL.bit.HSPCLKDIV = 000; // Clock ratio to SYSCLKOUT EPwm1Regs.TBCTL.bit.CLKDIV = 000; EPwm1Regs.TBCTL.bit.SYNCOSEL=1; EPwm1Regs.CMPA.half.CMPA =tbpr/2; // Set compare A value EPwm1Regs.CMPB = tbpr/2; // Set Compare B value EPwm1Regs.DBCTL.bit.OUT_MODE=3; EPwm1Regs.DBCTL.bit.POLSEL=2; EPwm1Regs.DBCTL.bit.IN_MODE=0; EPwm1Regs.DBRED=20; EPwm1Regs.DBFED=20; EPwm1Regs.AQCTLA.bit.CAU=2; // Set PWM1A on Zero EPwm1Regs.AQCTLA.bit.CAD=1; EPwm1Regs.AQCTLB.bit.CBU=2; EPwm1Regs.AQCTLB.bit.CBD=1; EPwm2Regs.TBCTL.bit.CTRMODE = 2; // Count up down EPwm2Regs.TBPRD = tbpr; // Set timer period EPwm2Regs.TBCTL.bit.PHSEN = 1; // Disable phase loading EPwm2Regs.TBPHS.half.TBPHS = phs; // Phase is 0 EPwm2Regs.TBCTL.bit.PHSDIR=0; EPwm2Regs.TBCTR = 0x0000; // Clear counter EPwm2Regs.TBCTL.bit.HSPCLKDIV = 000; // Clock ratio to SYSCLKOUT EPwm2Regs.TBCTL.bit.CLKDIV = 000; EPwm2Regs.TBCTL.bit.SYNCOSEL=0; EPwm2Regs.CMPA.half.CMPA =tbpr/2; // Set compare A value EPwm2Regs.CMPB = tbpr/2; // Set Compare B value EPwm2Regs.DBCTL.bit.OUT_MODE=3; EPwm2Regs.DBCTL.bit.POLSEL=2; EPwm2Regs.DBCTL.bit.IN_MODE=0; EPwm2Regs.DBRED=20; EPwm2Regs.DBFED=20; EPwm2Regs.AQCTLA.bit.CAU=2; // Set PWM1A on Zero EPwm2Regs.AQCTLA.bit.CAD=1; EPwm2Regs.AQCTLB.bit.CBU=2; EPwm2Regs.AQCTLB.bit.CBD=1; } void InitECapture() { // Initialization Time //======================= // ECAP module 1 config ECap1Regs.ECCTL1.bit.CAP1POL = 0; ECap1Regs.ECCTL1.bit.CAP2POL = 1; ECap1Regs.ECCTL1.bit.CAP3POL = 0; ECap1Regs.ECCTL1.bit.CAP4POL = 1; ECap1Regs.ECCTL1.bit.CTRRST1 = 0; ECap1Regs.ECCTL1.bit.CTRRST2 = 0; ECap1Regs.ECCTL1.bit.CTRRST3 = 0; ECap1Regs.ECCTL1.bit.CTRRST4 = 0; ECap1Regs.ECCTL1.bit.CAPLDEN = 1; ECap1Regs.ECCTL1.bit.PRESCALE = 0; ECap1Regs.ECCTL2.bit.CAP_APWM = 0; ECap1Regs.ECCTL2.bit.CONT_ONESHT = 0; ECap1Regs.ECCTL2.bit.SYNCO_SEL = 1; ECap1Regs.ECCTL2.bit.SYNCI_EN = 0; ECap1Regs.ECCTL2.bit.SWSYNC = 1; ECap1Regs.ECCTL2.bit.TSCTRSTOP = 1; // Start Counter ECap1Regs.ECCTL2.bit.REARM = 1; // arm one-shot ECap1Regs.ECCTL1.bit.CAPLDEN = 1; // Enable CAP1-CAP4 register loads ECap1Regs.ECEINT.bit.CEVT4 = 1; // 4 events = interrupt ECap2Regs.ECCTL1.bit.CAP1POL = 0; ECap2Regs.ECCTL1.bit.CAP2POL = 1; ECap2Regs.ECCTL1.bit.CAP3POL = 0; ECap2Regs.ECCTL1.bit.CAP4POL = 1; ECap2Regs.ECCTL1.bit.CTRRST1 = 0; ECap2Regs.ECCTL1.bit.CTRRST2 = 0; ECap2Regs.ECCTL1.bit.CTRRST3 = 0; ECap2Regs.ECCTL1.bit.CTRRST4 = 0; ECap2Regs.ECCTL1.bit.CAPLDEN = 1; ECap2Regs.ECCTL1.bit.PRESCALE = 0; ECap2Regs.ECCTL2.bit.CAP_APWM = 0; ECap2Regs.ECCTL2.bit.CONT_ONESHT = 0; ECap2Regs.ECCTL2.bit.SYNCO_SEL = 2; ECap2Regs.ECCTL2.bit.SYNCI_EN = 1; ECap2Regs.ECCTL2.bit.TSCTRSTOP = 1; // Start Counter ECap2Regs.ECCTL2.bit.REARM = 1; // arm one-shot ECap2Regs.ECCTL1.bit.CAPLDEN = 1; // Enable CAP1-CAP4 register loads ECap2Regs.ECEINT.bit.CEVT4 = 1; // 4 events = interrupt } __interrupt void ecap1_isr(void) { EPwm1Regs.TBPRD = tbpr; // Set timer period EPwm1Regs.CMPA.half.CMPA =tbpr/2; // Set compare A value EPwm1Regs.CMPB = tbpr/2; // Set Compare B value EPwm2Regs.TBPRD = tbpr; // Set timer period EPwm2Regs.CMPA.half.CMPA =tbpr/2; // Set compare A value EPwm2Regs.CMPB = tbpr/2; // Set Compare B value EPwm2Regs.TBPHS.half.TBPHS = phs; // Phase is 0 TSt1 = ECap1Regs.CAP1; // Fetch Time-Stamp captured at t1 TSt2 = ECap1Regs.CAP2; // Fetch Time-Stamp captured at t2 TSt3 = ECap1Regs.CAP3; // Fetch Time-Stamp captured at t3 TSt4 = ECap1Regs.CAP4; // Fetch Time-Stamp captured at t4 Period1 = TSt3-TSt1; // Calculate 1st period DutyOnTime1 = TSt2-TSt1; // Calculate On time DutyOffTime1 = TSt3-TSt2; // Calculate Off time ECap1Regs.ECCLR.bit.CEVT4 = 1; ECap1Regs.ECCLR.bit.INT = 1; ECap1Regs.ECCTL2.bit.REARM = 1; // Acknowledge this interrupt to receive more interrupts from group 4 PieCtrlRegs.PIEACK.all = PIEACK_GROUP4; } __interrupt void ecap2_isr(void) { TSt11 = ECap2Regs.CAP1; // Fetch Time-Stamp captured at t1 TSt21 = ECap2Regs.CAP2; // Fetch Time-Stamp captured at t2 TSt31 = ECap2Regs.CAP3; // Fetch Time-Stamp captured at t3 TSt41 = ECap2Regs.CAP4; // Fetch Time-Stamp captured at t4 Period11 = TSt31-TSt11; // Calculate 1st period DutyOnTime11 = TSt21-TSt11; // Calculate On time DutyOffTime11 = TSt31-TSt21; // Calculate Off time theta=TSt11-TSt1; ECap2Regs.ECCLR.bit.CEVT4 = 1; ECap2Regs.ECCLR.bit.INT = 1; ECap2Regs.ECCTL2.bit.REARM = 1; // Acknowledge this interrupt to receive more interrupts from group 4 PieCtrlRegs.PIEACK.all = PIEACK_GROUP4; } // // InitEPwm2Example - // // // End of File //
Thank you.
Regards,
May
May,
I am trying to run it on my setup. I will get back to you Monday/Tuesday.
Thanks & Regards,
Santosh
Hi Santosh,
Thank you, we are looking forward for your feedback on this.
Regards,
May
May,
You can use timer and two eCAP module to capture the phase difference. Start timer to eCAP1 ISR, and then stop timer at eCAP2 capture. The timer count can be used as phase difference.
Regards,
Santosh