/*	SW-Universal Control Module - Factory Control Program
	WWW.EXTREME-FIRE.COM
	Target controller = ATTINY85-20PU microcontroller from ATMEL.
	Clock speed = 8 MHz internal.
	Development platform = AVR Studio 4  Version 4.15.623 Service Pack 3  Build 623.
	C compiler = WinAVR 20070525  Optimization = -Os
	Programer = AVR Dragon
	Hardware Schematic = SW-UCM all versions.
	Hardware Layout = SW-UCM all versions.

This program is fully released to the Public Domain by Terry Fritz 2007 / 2011.
  

History
	001 - Initial release  Oct. 26, 2011  Terry Fritz
	002 - Removed Temperature and EEPROM.  BOD to 1.8V.  Faster turn on to set outputs.  Fixed mode2 A/D scaling.
	003 - Removed extra A/D ranges.  250kHz ADC clock.
	004 - Fixed Pseudo Clock and tested - Works good!!  Clock is about +-2%.

	
Known issues:
	To use pin 1 (AUX1) the Reset Disable Fuse has to be set.
		( RSTDISBL = 1 )  They use pin 1 by defalt and will keep the pin high if not fixed.

	Set BrownOut voltage to 1.8V in fuses.

    Set Clock div/8 fuse off during programming


Future changes:
	None

*/


/*	Include libraries */
	#include <avr/io.h>			/* For all the odd ATTINY stuff */
	#include <avr/interrupt.h>	/* For PseudoClock */	

/*	Define ATTINY85 ports (PBx) to the I/O ports */
/*	Note that these port numbers or NOT the physical pin numbers! */
	#define IO1 4				/* IO1 to PB4 */
	#define IO2 3				/* IO2 to PB3 */
	#define IO3 5	 			/* IO3 to PB5 */
	#define IO4 2				/* IO4 to PB2 */
	#define OUT1 1				/* OUT1 to PB1 */
	#define OUT2 0				/* OUT2 to PB0 */
	#define Ground 10  			/* Internal A/D ground used for calibration */
			

/* Function prototypes */
	void EnergizePorts(void);					/* Enables the FETs in a controled way */
	long GetVoltage(unsigned char Sensor);		/* Gets the Voltage (in mV) from the chosen source */
	void CalibrateAtoD(void);					/* Calibrates A/D convertor */
	void StartClock(void);						/* Start Pseudo Clock */


/*	Initialize variables */
	/* long is a 4 byte integer */
	long  Voltage = 0;						/* A/D convertor returned voltage in mV */
	long  VoltageOffset0 = 0;				/* A/D 5.0V REF offest error */
	volatile int long PseudoClock = 0;		/* Pseudo Clock value.  +-2% */

	long Input1 = 0;
	long Input2 = 0;
	long Input3 = 0;
	long Input4 = 0;
	int Output1 = 0;
	int Output2 = 0;
	int LED = 0;

	long LoopCount = 0;
	long counter1 = 0;
	long HighCount = 0;
	long LowCount = 0;
	volatile int long ClockStart = 0;
	volatile int long LoopTime = 0;


int main(void)
{	/* ====== Start of main ====== */

/* MAIN POWER UP */

	/* Energize drive circuits */
	EnergizePorts();	/* Energize drive circuits */
	StartClock();		/* Start Clock */
	CalibrateAtoD();	/* Setup A/D parameters */

	
/* ########## MAIN SCANNING LOOP ########## */
MainLoop:

	LoopCount++;  // Note used here

	ClockStart = PseudoClock;  // Start time of cycle


	HighCount = 0; LowCount = 0;  // Clear counters

	for(counter1 = 0; counter1 < 10; counter1++)  // Test trigger voltage 10 times.
		{
		// Get port voltages  ~160uS per test.
		Input1 = GetVoltage(IO1);
		if (Input1 >= 5000) {HighCount++;} else {LowCount++;}
		}

	if (HighCount >= 3) {Output1 = 1;} else {Output1 = 0;}  // Ouput on if trigger was on 3 or more tests 
	LED = Output1;  // Turn on LED with output

	//  Just a delay so the cycle time is 2mS
	LoopTime = PseudoClock - ClockStart;
	do {LoopTime = PseudoClock - ClockStart;} while (LoopTime < 20);

	// Actually set output port values
	PORTB = LED * 4 + Output1 * 2 + Output2;

goto MainLoop;
/* ########## END MAIN SCANNING LOOP ########## */

}  /* ====== End of main ====== */



/* FUNCTIONS */


void StartClock(void)
	{
	/* 100uS real time clock setup on 8 bit counter */
	TCCR1 = 0b10000000; 			// clear timer1 when it matches the value in OCR1C
	TIMSK = 0b01000000;	            // enable interrupt when OCR1A matches the timer value
	sei();                          // enable global interrupts
    OCR1A = 100;                    // set the match value for interrupt 8MHz clock / 800 = 100uS 
    OCR1C = 100;                    // and the same match value to clear the timer  
	TCCR1 = 0b10000100; 			// Divide by 8 prescaler (this starts the timer)
	}
	

ISR(TIM1_COMPA_vect){PseudoClock++;}  /* Real time clock update routine on 100uS interrupt */


void EnergizePorts(void)
	{
	PORTB = 0x00;	/* Set pullups off */ 
	DDRB = 0b00000111;	/* Set port B pins 0, 1 and 2 for output */
	PORTB = 0x00;	/* Set port B pin 0 to 0 and pin 1 to 0 */
	}


long GetVoltage(unsigned char Sensor)  // Takes about 160uS
	{
	/* Select input Source */
		if (Sensor == IO3) {ADMUX = 0x00;}
		if (Sensor == IO4) {ADMUX = 0x01;}
		if (Sensor == IO1) {ADMUX = 0x02;}
		if (Sensor == IO2) {ADMUX = 0x03;}
		if (Sensor == Ground) {ADMUX = 0x0D;}	/* Internal ground for calibration */
	/* Start A/D conversion */
	ADCSRA = 0b11000101;  						/* Start A/D conversion (bit 6 is set) 250kHz ADC clock*/
	/* Test if done (bit 6 goes clear, but is set when A/D is complete) */
	do {} while (bit_is_set(ADCSRA,6)); 		// This could be fixed now with the new clock!
	/* Get voltage Vref = 5000mV  Rdivider = 1/4  Full range is 20V */
	Voltage = ADCW;								/* This word is the 10 bit A/D result */
	Voltage = Voltage - VoltageOffset0;  		/* A/D Offset error adjustment */
	if (Voltage < 0) {Voltage = 0;}				/* If negative fix it */
	Voltage = ((Voltage * 20000) / 1023);		/* Convert A/D full range (1023) to 19980mV or 19.98V */
	return Voltage;
	}


void CalibrateAtoD(void)
	/* 5.0V REF  Range = 20V  1023 steps */
	{
	VoltageOffset0 = 0;						/* Clear old value */
	VoltageOffset0 = GetVoltage(Ground);	/* Run the converter with grounded input */
	VoltageOffset0 = ADCW;					/* Get the raw A/D converter output word */
	}