//Port Mirror 2
//Program to mirror one port (Receiver) to another (Controller)
//Written for PIC12F683 / CC5X compiler

//Personal and non-commercial use encouraged
//Copyright 2007 - David Theunissen - See www.flyelectric.ukgateway.net

//PREPROCESSOR section ========================================================

#include "12F683.H"				//PIC header file from CC5X
#include "delay_ms.h"			

#pragma config = 0b.11.1100.0100//Core device configuration

								
//VARIABLES section ===========================================================

#define ESC 	GPIO.1			//GP1 (Pin6)
#define RX 		GPIO.3			//GP3 (Pin4)
#define LED 	GPIO.5			//GP5 (Pin2)

char p;


//FUNCTIONS section ===========================================================

void esc_rx()					//Function to mirror RX input to ESC output
{
	//Time high pulse
		while (RX==0);			//Wait for RX to finish being low
		TMR2ON = 1;				//Start Timer2 (increments TMR2 to 255 before looping)
								//Tests using delay_ms(): 63=1ms, 126=2ms, 188=3ms
		while (RX==1);			//Wait for RX to finish being high
		TMR2ON = 0;				//Stop Timer2
		
	//Make ESC go high for same duration
		PR2 = TMR2;				//Timer 2 counts to the value set in PR2
		TMR2=0;					//Initialise Timer2
		
		ESC=1;
		TMR2ON = 1;				//Start Timer2 (timer increments to PR2 value)
		while(TMR2IF==0);		//TMR2IF flag is set to 1 when Timer2 reaches PR2
		
	//Make ESC low and rest flags
		ESC = 0;
		TMR2ON = 0;				//Stop Timer2
		TMR2IF = 0;				//Reset interrupt flag
		TMR2 = 0;				//Initialise Timer2
		PR2 = 255;				//Set PR2 ('period register') to its max so as to not inhibit Timer2
								//In theory this should happen automatically each time it is used
								//But this requires interrupts to be enabled which has other effects
		
}
		
//-----------------------------------------------------------------------------

void main()						//main program
{
//Main port settings
//	TRISIO0 = 1;				//Sets GP0/AN0 (pin7) to Input (Cell1)
	TRISIO1 = 0;				//Sets GP1/AN1 (pin6) to Output (ESC)
//	TRISIO2 = 1;				//sets GP2/AN2 (pin5) to Input (Cell3)
	TRISIO3 = 1;				//sets GP3 (pin4) to Input (RX)
//	TRISIO4 = 0;				//sets GP4/AN3 (pin3) to Output
	TRISIO5 = 0;				//Sets GP5 (pin2) to Output (LED)
    
//	ANS0 = 1;					//Sets AN0 (pin7) to analogue
	ANS1 = 0;					//Sets AN1 (pin6) to digital (ESC)
//	ANS2 = 1;					//Sets AN2 (pin5) to analogue
//	ANS3 = 0;					//Sets AN3 (pin3) to digital
    
    CMCON0 = 0b.111;			//Switches all 3 comparator ports off

//Static Timer2 settings
	T2CON.1 = 1;				//Prescale 16
	
//Initialise ESC output
	ESC=0;						//Start ESC low for safety

//Flash LED three times on startup	
	for (p=0; p<3; p++)
	{
		LED=1;
		delay_ms(250);
		LED=0;
		delay_ms(250);
	}

//-----------------------------------------------------------------------------
	while(1)
	{
		esc_rx();				//Mirror RX input to ESC output each time RX state changes
								//Put in a separate function to keep main function easier to read
								//Function ends with ESC low

		//Put main program here (runs once per RX pulse cycle so must be <20ms long)
		
	}							//end while
}								//end main