/*
	APM_RC_APM2.cpp - Radio Control Library for Ardupilot Mega 2.0. Arduino
	Code by Jordi Muņoz and Jose Julio. DIYDrones.com

	This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

	RC Input : PPM signal on IC4 pin
	RC Output : 11 Servo outputs (standard 20ms frame)

	Methods:
		Init() : Initialization of interrupts an Timers
		OutpuCh(ch,pwm) : Output value to servos (range : 900-2100us) ch=0..10
		InputCh(ch) : Read a channel input value.  ch=0..7
		GetState() : Returns the state of the input. 1 => New radio frame to process
		             Automatically resets when we call InputCh to read channels

*/
#include "APM_RC_APM2.h"

#include <avr/interrupt.h>
#if defined(ARDUINO) && ARDUINO >= 100
	#include "Arduino.h"
#else
	#include "WProgram.h"
#endif

#if !defined(__AVR_ATmega1280__) && !defined(__AVR_ATmega2560__)
# error Please check the Tools/Board menu to ensure you have selected Arduino Mega as your target.
#else

// Variable definition for Input Capture interrupt
volatile uint16_t APM_RC_APM2::_PWM_RAW[NUM_CHANNELS] = {2400,2400,2400,2400,2400,2400,2400,2400};
volatile uint8_t APM_RC_APM2::_radio_status=0;

/****************************************************
   Input Capture Interrupt ICP5 => PPM signal read
 ****************************************************/
void APM_RC_APM2::_timer5_capt_cb(void)
{
  static uint16_t prev_icr;
  static uint8_t frame_idx;
  uint16_t icr;
  uint16_t pwidth;

  icr = ICR5;
  // Calculate pulse width assuming timer overflow TOP = 40000
  if ( icr < prev_icr ) {
    pwidth = ( icr + 40000 ) - prev_icr;
  } else {
    pwidth = icr - prev_icr;
  }

  // Was it a sync pulse? If so, reset frame.
  if ( pwidth > 8000 ) {
    frame_idx=0;
  } else {
    // Save pulse into _PWM_RAW array.
    if ( frame_idx < NUM_CHANNELS ) {
      _PWM_RAW[ frame_idx++ ] = pwidth;
      // If this is the last pulse in a frame, set _radio_status.
      if (frame_idx >= NUM_CHANNELS) {
        _radio_status = 1;
      }
    }
  }
  // Save icr for next call.
  prev_icr = icr;
}


// Constructors ////////////////////////////////////////////////////////////////

APM_RC_APM2::APM_RC_APM2()
{
}

// Public Methods //////////////////////////////////////////////////////////////
void APM_RC_APM2::Init( Arduino_Mega_ISR_Registry * isr_reg )
{
  // --------------------- TIMER1: OUT1 and OUT2 -----------------------
  pinMode(12,OUTPUT); // OUT1 (PB6/OC1B)
  pinMode(11,OUTPUT); // OUT2 (PB5/OC1A)

  // WGM: 1 1 1 0. Clear Timer on Compare, TOP is ICR1.
  // CS11: prescale by 8 => 0.5us tick
  TCCR1A =((1<<WGM11));
  TCCR1B = (1<<WGM13)|(1<<WGM12)|(1<<CS11);
  ICR1 = 40000; // 0.5us tick => 50hz freq
  OCR1A = 0xFFFF; // Init OCR registers to nil output signal
  OCR1B = 0xFFFF;

  // --------------- TIMER4: OUT3, OUT4, and OUT5 ---------------------
  pinMode(8,OUTPUT); // OUT3 (PH5/OC4C)
  pinMode(7,OUTPUT); // OUT4 (PH4/OC4B)
  pinMode(6,OUTPUT); // OUT5 (PH3/OC4A)

  // WGM: 1 1 1 0. Clear Timer on Compare, TOP is ICR4.
  // CS41: prescale by 8 => 0.5us tick
  TCCR4A =((1<<WGM41));
  TCCR4B = (1<<WGM43)|(1<<WGM42)|(1<<CS41);
  OCR4A = 0xFFFF; // Init OCR registers to nil output signal
  OCR4B = 0xFFFF;
  OCR4C = 0xFFFF;
  ICR4 = 40000; // 0.5us tick => 50hz freq

  //--------------- TIMER3: OUT6, OUT7, and OUT8 ----------------------
  pinMode(3,OUTPUT); // OUT6 (PE5/OC3C)
  pinMode(2,OUTPUT); // OUT7 (PE4/OC3B)
  pinMode(5,OUTPUT); // OUT8 (PE3/OC3A)

  // WGM: 1 1 1 0. Clear timer on Compare, TOP is ICR3
  // CS31: prescale by 8 => 0.5us tick
  TCCR3A =((1<<WGM31));
  TCCR3B = (1<<WGM33)|(1<<WGM32)|(1<<CS31);
  OCR3A = 0xFFFF; // Init OCR registers to nil output signal
  OCR3B = 0xFFFF;
  OCR3C = 0xFFFF;
  ICR3 = 40000; // 0.5us tick => 50hz freq

  //--------------- TIMER5: PPM INPUT ---------------------------------
  // Init PPM input on Timer 5
  pinMode(48, INPUT);  // PPM Input (PL1/ICP5)
  pinMode(45, OUTPUT); // OUT10 (PL4/OC5B)
  pinMode(44, OUTPUT); // OUT11 (PL5/OC5C)

  // WGM: 1 1 1 1. Fast PWM, TOP is OCR5A
  // COM all disabled.
  // CS51: prescale by 8 => 0.5us tick
  // ICES5: Input Capture on rising edge
  TCCR5A =((1<<WGM50)|(1<<WGM51));
  // Input Capture rising edge
  TCCR5B = ((1<<WGM53)|(1<<WGM52)|(1<<CS51)|(1<<ICES5));
  OCR5A = 40000; // 0.5us tick => 50hz freq. The input capture routine
                 // assumes this 40000 for TOP.

  isr_reg->register_signal( ISR_REGISTRY_TIMER5_CAPT, _timer5_capt_cb );
  // Enable Input Capture interrupt
  TIMSK5 |= (1<<ICIE5);
}

void APM_RC_APM2::OutputCh(unsigned char ch, uint16_t pwm)
{
  pwm=constrain(pwm,MIN_PULSEWIDTH,MAX_PULSEWIDTH);
  pwm<<=1;   // pwm*2;

 switch(ch)
  {
    case 0:  OCR1B=pwm; break;  // out1
    case 1:  OCR1A=pwm; break;  // out2
    case 2:  OCR4C=pwm; break;  // out3
    case 3:  OCR4B=pwm; break;  // out4
    case 4:  OCR4A=pwm; break;  // out5
    case 5:  OCR3C=pwm; break;  // out6
    case 6:  OCR3B=pwm; break;  // out7
    case 7:  OCR3A=pwm; break;  // out8
    case 9:  OCR5B=pwm; break;  // out10
    case 10: OCR5C=pwm; break;  // out11
  }
}

uint16_t APM_RC_APM2::OutputCh_current(uint8_t ch)
{
	uint16_t pwm=0;
	switch(ch){
	case 0:  pwm=OCR1B; break;  // out1
	case 1:  pwm=OCR1A; break;  // out2
	case 2:  pwm=OCR4C; break;  // out3
	case 3:  pwm=OCR4B; break;  // out4
	case 4:  pwm=OCR4A; break;  // out5
	case 5:  pwm=OCR3C; break;  // out6
	case 6:  pwm=OCR3B; break;  // out7
	case 7:  pwm=OCR3A; break;  // out8
	case 9:  pwm=OCR5B; break;  // out10
	case 10: pwm=OCR5C; break;  // out11
	}
	return pwm>>1;
}

void APM_RC_APM2::enable_out(uint8_t ch)
{
  switch(ch) {
    case 0: TCCR1A |= (1<<COM1B1); break; // CH_1 : OC1B
    case 1: TCCR1A |= (1<<COM1A1); break; // CH_2 : OC1A
    case 2: TCCR4A |= (1<<COM4C1); break; // CH_3 : OC4C
    case 3: TCCR4A |= (1<<COM4B1); break; // CH_4 : OC4B
    case 4: TCCR4A |= (1<<COM4A1); break; // CH_5 : OC4A
    case 5: TCCR3A |= (1<<COM3C1); break; // CH_6 : OC3C
    case 6: TCCR3A |= (1<<COM3B1); break; // CH_7 : OC3B
    case 7: TCCR3A |= (1<<COM3A1); break; // CH_8 : OC3A
    case 9: TCCR5A |= (1<<COM5B1); break; // CH_10 : OC5B
    case 10: TCCR5A |= (1<<COM5C1); break; // CH_11 : OC5C
  }
}

void APM_RC_APM2::disable_out(uint8_t ch)
{
  switch(ch) {
    case 0: TCCR1A &= ~(1<<COM1B1); break; // CH_1 : OC1B
    case 1: TCCR1A &= ~(1<<COM1A1); break; // CH_2 : OC1A
    case 2: TCCR4A &= ~(1<<COM4C1); break; // CH_3 : OC4C
    case 3: TCCR4A &= ~(1<<COM4B1); break; // CH_4 : OC4B
    case 4: TCCR4A &= ~(1<<COM4A1); break; // CH_5 : OC4A
    case 5: TCCR3A &= ~(1<<COM3C1); break; // CH_6 : OC3C
    case 6: TCCR3A &= ~(1<<COM3B1); break; // CH_7 : OC3B
    case 7: TCCR3A &= ~(1<<COM3A1); break; // CH_8 : OC3A
    case 9: TCCR5A &= ~(1<<COM5B1); break; // CH_10 : OC5B
    case 10: TCCR5A &= ~(1<<COM5C1); break; // CH_11 : OC5C
  }
}

uint16_t APM_RC_APM2::InputCh(unsigned char ch)
{
	uint16_t result;

	if (_HIL_override[ch] != 0) {
		return _HIL_override[ch];
	}

	// we need to block interrupts during the read of a 16 bit
	// value
	cli();
	result = _PWM_RAW[ch];
	sei();
	// Because timer runs at 0.5us we need to do value/2
	result >>= 1;

	// Limit values to a valid range
	result = constrain(result,MIN_PULSEWIDTH,MAX_PULSEWIDTH);
	_radio_status = 0; // Radio channel read
	return result;
}

unsigned char APM_RC_APM2::GetState(void)
{
  return(_radio_status);
}

// InstantPWM is not implemented!

void APM_RC_APM2::Force_Out(void) { }
void APM_RC_APM2::Force_Out0_Out1(void) { }
void APM_RC_APM2::Force_Out2_Out3(void) { }
void APM_RC_APM2::Force_Out6_Out7(void) { }

/* ---------------- OUTPUT SPEED CONTROL ------------------ */

void APM_RC_APM2::SetFastOutputChannels(uint32_t chmask, uint16_t speed_hz)
{
	uint16_t icr = _map_speed(speed_hz);

	if ((chmask & ( _BV(CH_1) | _BV(CH_2))) != 0) {
		ICR1 = icr;
	}

	if ((chmask & ( _BV(CH_3) | _BV(CH_4) | _BV(CH_5))) != 0) {
		ICR4 = icr;
	}

	if ((chmask & ( _BV(CH_6) | _BV(CH_7) | _BV(CH_8))) != 0) {
		ICR3 = icr;
	}
}

// allow HIL override of RC values
// A value of -1 means no change
// A value of 0 means no override, use the real RC values
bool APM_RC_APM2::setHIL(int16_t v[NUM_CHANNELS])
{
	uint8_t sum = 0;
	for (unsigned char i=0; i<NUM_CHANNELS; i++) {
		if (v[i] != -1) {
			_HIL_override[i] = v[i];
		}
		if (_HIL_override[i] != 0) {
			sum++;
		}
	}
		if (sum == 0) {
			return 0;
		} else {
			return 1;
		}
	_radio_status = 1;
}

void APM_RC_APM2::clearOverride(void)
{
	for (unsigned char i=0; i<NUM_CHANNELS; i++) {
		_HIL_override[i] = 0;
	}
}

#endif