// Author: Andrew Wilson
// Date: 6/28/2006
// Description: This program will control a stepper motor driver circuit.
//   it will monitor two inputs: analog potentiometer, and digital rpm sensor
//   the program will ramp the speed output of the motor depending on the 
//   position of the potentiomenter.  the rpm sensor will be used to ensure the
//   correct speed is maintained.

#include <18F2520.h>
#include "stepper_driver.h"
#fuses HS, NOWDT, NOLVP
#use delay(clock=CLOCKRATE)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, stream=PC)

int16 timer1 = 0;
int16 timer_step = 0;
int16 timer_step_set = 0;
int16 timer_debug_set = 0;
int16 timer_debug = 0;

void checkTimer()
{
	
	timer1 = get_timer1();
	set_timer1(0x0009); //start counting from zero (plus overhead)

	if(timer_step > timer1)
		timer_step -= timer1;
	else
		timer_step = 0x00;

	if(timer_debug > timer1)
		timer_debug -= timer1;
	else
		timer_debug = 0x00;

}

int main()
{
	int16 v_reading; //the pic18f2550 has a 10-bit A-to-D converter
					 //that will give us 255 possible steps (should be 1024, but wasn't working)
	int16 loop;

	setup_timer_1(T1_INTERNAL|T1_DIV_BY_1);

	printf("Stepper Motor Interface v1, brought to you by:\n\r");
	printf("Andrew Wilson\n\r");
	printf("reconnsworld.com\n\r");

	//this sets up PIN A0 as an analog-in pin.
	//it is OR'd with VSS_VDD which forces the pic to use
	//  ground and VDD as reference voltages
	setup_adc_ports(AN0_TO_AN1 || VSS_VDD);

	//this (i think) sets the ADC to clock via the internal
	//instruction clock
	setup_adc(ADC_CLOCK_INTERNAL);

	set_adc_channel(1);  //we will only be using this channel
						 //no need to set it again.

	// Initialize stepper timing here
	timer_step_set = (int16)140;
	timer_debug_set = 5000; //.001/(1.0*CLOCKRATE/(1.0*CLOCKSCALER*PRESCALER));

	// Initialize stepper motor pins here
	//-----------------------------------
	output_low(STEPPER_DIR);
	output_high(STEPPER_ENA);	

	loop = 0;
	while(1)
	{

		if(timer_debug == 0)
		{
			output_toggle(PIN_A0);
			timer_debug = timer_debug_set;
		}

		//This works out to be 20mS -- don't have to scan that much
		if(loop == 100000)
		{
			loop = 0;
			v_reading = read_adc();
			if(v_reading == 0)
				timer_step_set = MIN_INCS;
			else
				timer_step_set = (int16)((MAX_INCS-MIN_INCS)*( ((1.0)*v_reading) / (float)MAX_READING ) + MIN_INCS);
			//printf("%lu, %lu\n\r", v_reading, timer_step_set); //only use this for debug
		}
		

		if(timer_step == 0)
		{
			output_toggle(STEPPER_STP);
			timer_step = timer_step_set;
		}

		checkTimer();
		loop++;

	}

	return 1;
}