example_2833xeqep_pos_speed.c

TI公司TMS320F2883x浮点DSP的详细应用例程

// TI File $Revision: /main/9 $
// Checkin $Date: August 16, 2007   10:37:57 $
//###########################################################################
//
// FILE:	Example_2833xEqep_pos_speed_.c
//
// TITLE:	EQEP Speed and Position measurement
//
// ASSUMPTIONS:
//
//    This program requires the DSP2833x header files.
//
//    This project uses fixed-point math.  Be sure that the Code Composer Studio compiler
//    is not configured for floating-point math (fixed-point is default).
//
//    Test requires the following hardware connections from EPWM1 and
//    GPIO pins (simulating QEP sensor) to QEP peripheral
//
//       GPIO20/EQEP1A <- GPIO0/EPWM1A (simulates EQEP Phase A signal)
//       GPIO21/EQEP1B <- GPIO1/EPWM1B (simulates EQEP Phase B signal)
//       GPIO23/EQEP1I <- GPIO4 (simulates EQEP Index Signal)
//
//
//    As supplied, this project is configured for "boot to SARAM"
//    operation.  The 2833x Boot Mode table is shown below.
//    For information on configuring the boot mode of an eZdsp,
//    please refer to the documentation included with the eZdsp,
//
//       $Boot_Table:
//
//         GPIO87   GPIO86     GPIO85   GPIO84
//          XA15     XA14       XA13     XA12
//           PU       PU         PU       PU
//        ==========================================
//            1        1          1        1    Jump to Flash
//            1        1          1        0    SCI-A boot
//            1        1          0        1    SPI-A boot
//            1        1          0        0    I2C-A boot
//            1        0          1        1    eCAN-A boot
//            1        0          1        0    McBSP-A boot
//            1        0          0        1    Jump to XINTF x16
//            1        0          0        0    Jump to XINTF x32
//            0        1          1        1    Jump to OTP
//            0        1          1        0    Parallel GPIO I/O boot
//            0        1          0        1    Parallel XINTF boot
//            0        1          0        0    Jump to SARAM	    <- "boot to SARAM"
//            0        0          1        1    Branch to check boot mode
//            0        0          1        0    Boot to flash, bypass ADC cal
//            0        0          0        1    Boot to SARAM, bypass ADC cal
//            0        0          0        0    Boot to SCI-A, bypass ADC cal
//                                              Boot_Table_End$
//
// DESCRIPTION:
//
//    This test will provide position measurement,  speed measurement using the capture unit, and
//    speed measurement using unit time out. This example uses the IQMath library. It is used
//    merely to simplify high-precision calculations.
//
//    See DESCRIPTION in Example_posspeed.c for more details on the calculations
//    performed in this example.
//
//    In addition to this file, the following files must be included in this project:
//    Example_posspeed.c - includes all eQEP functions
//    Example_EPwmSetup.c - sets up EPWM1A and EPWM1B as simulated QA and QB encoder signals
//    Example_posspeed.h - includes initialization values for pos and speed structure
//
//    Notes:
//    * Maximum speed is configured to 6000rpm(BaseRpm)
//    * Minimum speed is assumed at 10rpm for capture pre-scalar selection
//    * Pole pair is configured to 2 (pole_pairs)
//    * QEP Encoder resolution is configured to 4000counts/revolution (mech_scaler)
//      which means: 4000/4 = 1000 line/revolution quadrature encoder (simulated by EPWM1)
//    * EPWM1 (simulating QEP encoder signals) is configured for 5kHz frequency or 300 rpm
//      (=4*5000 cnts/sec * 60 sec/min)/4000 cnts/rev)
//    * 300 rpm EPWM1 speed will be measured by EQEP.
//
// 	  SPEEDRPM_FR: High Speed Measurement is obtained by counting the QEP input pulses
//              for 10ms (unit timer set to 100Hz).
//
//    SPEEDRPM_FR = { (Position Delta)/10ms } * 60 rpm
//
//
//    SPEEDRPM_PR: Low Speed Measurement is obtained by measuring time period of QEP edges.
//              Time measurement is averaged over 64edges for better results and
//              capture unit performs the time measurement using pre-scaled SYSCLK
//
//              Note that pre-scaler for capture unit clock is selected such that
//              capture timer does not overflow at the required minimum RPM speed
//
//          Watch Variables: qep_posspeed.SpeedRpm_fr - Speed meas. in rpm using QEP position counter
//                           qep_posspeed.SpeedRpm_pr - Speed meas. in rpm using capture unit
//                           qep_posspeed.theta_mech - Motor mechanical angle (Q15)
//                           qep_posspeed.theta_elec - Motor electrical angle (Q15)
//
//###########################################################################
// Original Author S.D.
//
// $TI Release: DSP2833x Header Files V1.01 $
// $Release Date: September 26, 2007 $
//###########################################################################

#include "DSP2833x_Device.h"     // DSP2833x Headerfile Include File
#include "DSP2833x_Examples.h"   // DSP2833x Examples Include File
#include "Example_posspeed.h"   // Example specific Include file

void initEpwm();
interrupt void prdTick(void);

POSSPEED qep_posspeed=POSSPEED_DEFAULTS;
Uint16 Interrupt_Count = 0;

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. Initalize 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

// For this case only init GPIO for eQEP1 and ePWM1
// This function is found in DSP2833x_EQep.c
   InitEQep1Gpio();
   InitEPwm1Gpio();
   EALLOW;
   GpioCtrlRegs.GPADIR.bit.GPIO4 = 1;    // GPIO4 as output simulates Index signal
   GpioDataRegs.GPACLEAR.bit.GPIO4 = 1;  // Normally low
   EDIS;
// 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.EPWM1_INT= &prdTick;
   EDIS;    // This is needed to disable write to EALLOW protected registers

// Step 4. Initialize all the Device Peripherals:
   initEpwm();  // This function exists in Example_EPwmSetup.c

// Step 5. User specific code, enable interrupts:
// Enable CPU INT1 which is connected to CPU-Timer 0:
   IER |= M_INT3;

// Enable TINT0 in the PIE: Group 3 interrupt 1
   PieCtrlRegs.PIEIER3.bit.INTx1 = 1;

// Enable global Interrupts and higher priority real-time debug events:
   EINT;   // Enable Global interrupt INTM
   ERTM;   // Enable Global realtime interrupt DBGM

   qep_posspeed.init(&qep_posspeed);

	for(;;)
	{
	}

}


interrupt void prdTick(void)                  // EPWM1 Interrupts once every 4 QCLK counts (one period)
{  Uint16 i;
   // Position and Speed measurement
   qep_posspeed.calc(&qep_posspeed);

   // Control loop code for position control & Speed contol
   Interrupt_Count++;
   if (Interrupt_Count==1000)                 // Every 1000 interrupts(4000 QCLK counts or 1 rev.)
   {
       EALLOW;
       GpioDataRegs.GPASET.bit.GPIO4 = 1;     // Pulse Index signal  (1 pulse/rev.)
       for (i=0; i<700; i++){
       }
       GpioDataRegs.GPACLEAR.bit.GPIO4 = 1;
	   Interrupt_Count = 0;                   // Reset count
	   EDIS;
   }

   // Acknowledge this interrupt to receive more interrupts from group 1
   PieCtrlRegs.PIEACK.all = PIEACK_GROUP3;
   EPwm1Regs.ETCLR.bit.INT=1;
}