//PULSE_WIDTH_1
//Program to measure pulse widths from receiver and use LED to reveal results
//Written for PIC12F683 to be compiled with the CC5X compiler
//Clock frequency left at 4MHz default
//Copyright David Theunissen 2007 www.flyelectric.ukgateway.net

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

#include "12F683.H"				//PIC chip file
//#include "delay_ms.h"

#pragma config = 0b.0.1100.0100	//Brown-out Detect disabled (first 0)
								//Code Protect off (1)
								//MCLR set to 'Internal' (1)
								//Powerup timer enabled (0)
								//Watchdog timer disabled (0)
								//Oscillator set to INTRCIO (100)
								
//VARIABLES section ===========================================================

#define LED1	GPIO.0			//Define pin7 as LED1
#define ESC 	GPIO.1			//ESC output defined (pin6)
#define RX		GPIO.3			//Pin4 is input from Receiver (NB: Disconnect from Rx when programming)
								//Change to GP5 if available (does not interfere with programming as does pin3

char PULSE;						//Variable to store duration of high pulse


//FUNCTIONS section ===========================================================
	
void main()
{
//Main port settings
	TRISIO0 = 0;				//Sets GP0 (pin7) to Output (LED1)
    TRISIO1 = 0;				//Sets GP1 (pin6) to Output (ESC)
    TRISIO3 = 1;				//Sets GP3 (pin4) to Intput (RX)
	
    ANS0 = 0;					//Disables ADC port AN0
    ANS1 = 0;					//Disables ADC port AN1
    CMCON0 = 0b.111;			//Switches all 3 comparator ports off

    
    while(1)
    {
    //measure receiver's throttle pulse----------------------------------------
    
		PULSE = 0;				//set pulse width variable to zero
		while (RX==0);			//Wait for RX signal to be low (to ensure full length of next high is measured)
		
		while (RX==1)			//Wait for RX signal to go high
			{
			PULSE++;			//increment pulse width variable while RX pulse is high
			}					//Measured at 100% ATV: Low+low_trim=123, Low+mid_trim=140, mid=190, full=242
								//Divide PULSE count by 125 to get pulse width in ms (eg: 140/125=1.12ms)
								//At 4MHz this implies 8 instructions per count @ 1uS each (eg: 140*8*1=1120uS)
								
	//use LED to test which throttle positions make LED come on/off---------------
	
		if (PULSE>=140)			//change number to tease out range of operation
	    {
	   	LED1=1;					//yes
		}
		else
		{
	   	LED1=0;					//no
		}
	    
	}							//end while
}								//end main