//###########################################################################
//
// FILE:	Example_2833xEqep_pos_speed.c
//
// TITLE:	eQEP Speed and Position measurement Example
//
//! \addtogroup f2833x_example_list
//! <h1>eQEP Speed and Position measurement (eqep_pos_speed)</h1>
//!
//! This example provides 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. \n
//! The example requires the following hardware connections from EPWM1 and
//! GPIO pins (simulating QEP sensor) to QEP peripheral.
//!    - eQEP1A <- ePWM1A (simulates eQEP Phase A signal)
//!    - eQEP1B <- ePWM1B (simulates eQEP Phase B signal)
//!    - eQEP1I <- GPIO4 (simulates eQEP Index Signal)
//!
//! 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
//!
//! Note:
//!    - 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)
//!    - 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
//!    - pre-scaler for capture unit clock is selected such that capture timer 
//!      does not overflow at the required minimum RPM speed.
//!
//! \b External \b Connections \n
//!   - Connect eQEP1A(GPIO20) to ePWM1A(GPIO0)(simulates eQEP Phase A signal)
//!   - Connect eQEP1B(GPIO21) to ePWM1B(GPIO1)(simulates eQEP Phase B signal)
//!   - Connect eQEP1I(GPIO23) to GPIO4 (simulates eQEP Index Signal)
//!
//! \b Watch \b Variables \n
//!  - 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)
//
//###########################################################################
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// $Release Date: $
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//###########################################################################

//
// Included Files
//
#include "DSP28x_Project.h"     // Device Headerfile and Examples Include File
#include "Example_posspeed.h"   // Example specific Include file

//
// Function Prototypes
//
void initEpwm();
__interrupt void prdTick(void);

//
// Globals
//
POSSPEED qep_posspeed=POSSPEED_DEFAULTS;
Uint16 Interrupt_Count = 0;

//
// Main
//
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

    //
    // For this case only init GPIO for eQEP1 and ePWM1
    // This function is found in DSP2833x_EQep.c
    //
    InitEQep1Gpio();
    InitEPwm1Gpio();
    EALLOW;
    
    //
    // GPIO4 as output simulates Index signal
    //
    GpioCtrlRegs.GPADIR.bit.GPIO4 = 1;
    
    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(;;)
    {
        
    }
}

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

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

//
// End of File
//

