/*
 * File:        ISR performance
 * Author:      Bruce Land
 * For use with Sean Carroll's Big Board
 * Target PIC:  PIC32MX250F128B
 */

////////////////////////////////////
// clock AND protoThreads configure!
// You MUST check this file!
#include "config_1_3_2.h"
// threading library
#include "pt_cornell_1_3_2.h"

////////////////////////////////////
// graphics libraries
// SPI channel 1 connections to TFT
#include "tft_master.h"
#include "tft_gfx.h"
// need for rand function
#include <stdlib.h>
// need for sine function
#include <math.h>
// The fixed point types
#include <stdfix.h>
////////////////////////////////////

// lock out timer interrupt during spi comm to port expander
// This is necessary if you use the SPI2 channel in an ISR
#define start_spi2_critical_section INTEnable(INT_T2, 0);
#define end_spi2_critical_section INTEnable(INT_T2, 1);

////////////////////////////////////
// some precise, fixed, short delays
// to use for extending pulse durations on the keypad
// if behavior is erratic
#define NOP asm("nop");
#define wait10 NOP;NOP;NOP;NOP;NOP;NOP;NOP;NOP;NOP;NOP;
// 20 cycles 
#define wait20 wait10; wait10;
// 40 cycles
#define wait40 wait20; wait20;
////////////////////////////////////

// string buffer
char buffer[60];

////////////////////////////////////


// interrupt ticks since beginning of song or note
volatile unsigned int ISR_time, ISR_time_exit, ISR_time_enter ;
volatile _Accum junk1, junk2, junk3; 

void __ISR(_TIMER_2_VECTOR, ipl2) Timer2Handler(void)
{
    // ISR prologue time
    ISR_time_enter = ReadTimer2() ; 
    mT2ClearIntFlag();
    // just a random arithmetic operation
    junk1 = junk2*junk3 ;
    // ISR exit time
    ISR_time_exit = ReadTimer2() ; 
}

// === print a line on TFT =====================================================
// print a line on the TFT
// string buffer
char buffer[60];
void printLine(int line_number, char* print_buffer, short text_color, short back_color){
    // line number 0 to 31 
    /// !!! assumes tft_setRotation(0);
    // print_buffer is the string to print
    int v_pos;
    v_pos = line_number * 10 ;
    // erase the pixels
    tft_fillRoundRect(0, v_pos, 239, 8, 1, back_color);// x,y,w,h,radius,color
    tft_setTextColor(text_color); 
    tft_setCursor(0, v_pos);
    tft_setTextSize(1);
    tft_writeString(print_buffer);
}

void printLine2(int line_number, char* print_buffer, short text_color, short back_color){
    // line number 0 to 31 
    /// !!! assumes tft_setRotation(0);
    // print_buffer is the string to print
    int v_pos;
    v_pos = line_number * 20 ;
    // erase the pixels
    tft_fillRoundRect(0, v_pos, 239, 16, 1, back_color);// x,y,w,h,radius,color
    tft_setTextColor(text_color); 
    tft_setCursor(0, v_pos);
    tft_setTextSize(2);
    tft_writeString(print_buffer);
}

// Predefined colors definitions (from tft_master.h)
//#define	ILI9340_BLACK   0x0000
//#define	ILI9340_BLUE    0x001F
//#define	ILI9340_RED     0xF800
//#define	ILI9340_GREEN   0x07E0
//#define ILI9340_CYAN    0x07FF
//#define ILI9340_MAGENTA 0xF81F
//#define ILI9340_YELLOW  0xFFE0
//#define ILI9340_WHITE   0xFFFF

// === thread structures ============================================
// thread control structs
static struct pt pt_timer ;

// system 1 second interval tick
int sys_time_seconds ;

// === Timer Thread =================================================
// update a 1 second tick counter
static PT_THREAD (protothread_timer(struct pt *pt))
{
    PT_BEGIN(pt);
     // timer readout
     sprintf(buffer,"%s", "ISR Time in cycles \r\n");
     printLine2(0, buffer, ILI9340_WHITE, ILI9340_BLACK);
     
     // set up LED to blink
     mPORTASetBits(BIT_0 );	//Clear bits to ensure light is off.
     mPORTASetPinsDigitalOut(BIT_0 );    //Set port as output
     
      while(1) {
        // yield time 1 second
        PT_YIELD_TIME_msec(1000) ;
        sys_time_seconds++ ;
        // toggle the LED on the big board
        mPORTAToggleBits(BIT_0);
        
        // zero all the ISR variables
        ISR_time_exit = 0 ;
        ISR_time_enter = 0 ;
        WriteTimer2(0);
        // trigger the ISR
        INTSetFlag(INT_T2);
        // wait 10 cycles to avoid concurenty issures
        wait10 ;
        // measure time since timer was zeroed
        // and subtract 10 for the 10 cycle wait
        ISR_time = ReadTimer2()-10;
              
        // draw sys_time
        sprintf(buffer,"%d %d %d", ISR_time_enter, ISR_time_exit, ISR_time);//sys_time_seconds);
        printLine2(1, buffer, ILI9340_YELLOW, ILI9340_BLACK);
        
        
        // !!!! NEVER exit while !!!!
      } // END WHILE(1)
  PT_END(pt);
} // timer thread

// === Main  ======================================================
void main(void) {
 //SYSTEMConfigPerformance(PBCLK);
  
  ANSELA = 0; ANSELB = 0; 

  // set up DAC on big board
  // timer interrupt //////////////////////////
    // Set up timer2 on,  interrupts, internal clock, prescalar 1, toggle rate
    OpenTimer2(T2_ON | T2_SOURCE_INT | T2_PS_1_1,1000); // 24 works, 22 no

    // set up the timer interrupt with a priority of 2
    ConfigIntTimer2(T2_INT_ON | T2_INT_PRIOR_2);
    mT2ClearIntFlag(); // and clear the interrupt flag

  // init the display
  // NOTE that this init assumes SPI channel 1 connections
  tft_init_hw();
  tft_begin();
  tft_fillScreen(ILI9340_BLACK);
  //240x320 vertical display
  tft_setRotation(0); // Use tft_setRotation(1) for 320x240

  // === setup system wide interrupts  ========
  INTEnableSystemMultiVectoredInt();
  
  // === config threads ==========
  // turns OFF UART support and debugger pin, unless defines are set
  PT_setup();

  // init the threads
  PT_INIT(&pt_timer);
  
  // round-robin scheduler for threads
  while (1){
      PT_SCHEDULE(protothread_timer(&pt_timer));
      }
  } // main

// === end  ======================================================