Arduino Slider Control

/*

This version works, but needs to be cleaned up.
The LCD Screen, Keyboard and Stepper motor are all driven off
the same thread. So when driving the motor the keyboard can be
bit sluggish.

You may need to adjust the keyboard debounce time.

*/


// MAP out all the Inputs and Outputs
// 
//	Arduino Duemilenove
//	14 digital IO (6PWM outputs)
//	6 Analog Inputs
//	32k Flash Memory
//	2k SRAM
//	1k EEPROM
//	16Mhz Clock Speed
//

/*
**		IO for the LCD Display
*/

#define	IOA_KEY_INPUT	0	// 5 Key input on Analogue input 0
/*		IO_LCD_DB0		4	// LCD nibble output
		IO_LCD_DB1		5
		IO_LCD_DB2		6
		IO_LCD_DB3		7
		IO_LCD_RS		8
		IO_LCD_ENABLE	9 */
#define	IO_LCD_BL		10	// LCD Backlight Control


#define	IO_SHOT					13	// Output to take shot on camera
#define	IO_LIMIT_SWITCHES		A1	// Input limit switches on AIO via resistor totom pole
#define	IO_STEP_DIR				3	// Direction of Stepper
#define	IO_STEP_STEP	        2	// Step the Stepper Motor
#define IO_STEP_ENABLE          12	// enable the Stepper Motor

/* DEFINE the keypad input keys	*/
#define	NUM_KEYS		5
#define	KEY_NULL		-1
#define	KEY_RIGHT		0
#define	KEY_UP			1
#define	KEY_DOWN		2
#define	KEY_LEFT		3
#define	KEY_SELECT		4
#define	KEY_DEBOUNC_MS	200
#define	KEY_REPEAT_MS	200
#define	LCD_SCREENSAVE_TIME	10000	// time to fade LCD with no input

#define	STEPS_PER_MM	1260		// number of steps per mm movement
#define	STROKE_MM		650			// full stroke of slider in mm

#define  NUM_MENU		12		// Number of menu items
#define  MENU_HOME		0		// Home menu position
#define  MENU_INTERVAL	1		// Time interval between shots (this includes exposure
#define	 MENU_EXPOSURE	2		// Exposure time (must be less than interval)
#define  MENU_TIME		3		// Time to travel full stroke
#define  MENU_SHOTS		4		// Total number of shots
#define  MENU_STROKE	5		// Total stroke of slider
#define  MENU_POSITION	6		// Position on slider
#define  MENU_DIRECTION	7		// Direction of travel
#define	 MENU_DOLLY		8		// dolly vs Step mode
#define	 MENU_POWER		9		// Power save mode
#define  MENU_LCD		10		// Brightness of LCD screen
#define	 MENU_MANUAL	11		// Drive in Manual Mode

#define	 LCD_CHAR_WIDTH	16		// Width of LCD display

/**********	Header Files	***********************/

#include <LiquidCrystal.h>
#include <stdio.h>

/********** GLOBAL Variables **********************/

		boolean	bDebug	= 0;

		LiquidCrystal	lcd(8, 9, 4, 5, 6, 7);	// Create object to control the LCD

		int		nMenu = 0;
		char	sMenu[NUM_MENU][LCD_CHAR_WIDTH + 1] = {
						"Home", 
						"Interval",
						"Exposure",
						"Time (min)", 
						"Shots",
						"Stroke (mm)",
						"Position (mm)", 
						"Direction", 
						"Dolly-Step Mode", 
						"Power Save", 
						"LCD Brightness",
						"Manual"};

        boolean	bIsPowerSave = true;		// disable the motor when stopped to save power.	
        boolean	bStepDirUP = true;			// Stepper direction (UP/DOWN)
		boolean	bShutterOpen = false;		// Camera taking shot
		boolean	bIsRunning = false;			// is running
		boolean	bModeDolly = false;			// in dolly mode vs step mode
        int		nSpeedMinutes = 60;			// Speed, Minutes for stroke
		long	nCycleTimeMS = 50;			// scan cycle time ms

		long	PreviousShotMS = 0;
		int		nShotInterval = 30;			// Camera Shutter Interval
		int		nShotExposure = 1;			// Camera Shutter Exposure
		int		nShotNumber = 0;			// Current Shot number
		int		nNextShotNumber = 0;		// Waiting for this shot number
		int		nMaxShots = 120;			// Number of shots to take
		long	nStroke = STROKE_MM;		// Full Stroke of the slide
		long	nPositionMM = 0;			// position of the slider MM
		long	nPositionStep = 0;			// position of the slider in steps
		int		nLCDBrightness = 255;		// the brighness of the LCD screen


 // minimum uSeconds between motor steps 
unsigned int motor_min_step = 200;			// fastest stepping speed
unsigned int motor_max_step = 3000;



/*
**	FUNCTION:		setup
**
**	DESCRIPTION:	Setup the hardware and software constructions. This
**					function is only called once on powerup or reset.
**
*/

void 
setup(void)
{ 

	if (bDebug)
	{
		Serial.begin(9600);
	}

	// Initialise the Liquid Crystal Display
	analogWrite(IO_LCD_BL, nLCDBrightness);
	lcd.begin(16, 2);
	lcd.print("Light Slider");
	lcd.setCursor(0, 1);
	lcd.print("Version 0.5a");
	delay(1000); // pause to read version

	// Initialise the Stepper Motor
	pinMode(IO_STEP_DIR, OUTPUT);
	pinMode(IO_STEP_STEP, OUTPUT);
	pinMode(IO_STEP_ENABLE, OUTPUT);

	// Initialise the Camera Remote
	pinMode(IO_SHOT, OUTPUT);

//	PATCH could use MsTimer2 for parallel threads and interrupts

}

/*
**	FUNCTION:		loop
**
**	DESCRIPTION:	Called in a loop to process the program.
**
**
*/

void 
loop(void)
{
	
	UserInterface();
	UpdateDisplay();
	
	CheckLimits();
	if (bIsRunning)
	{
		DriveStepper();	
		FireCamera();
	}
}


char*
GetDisplayName(int menu)
{
static  char    sBuf[LCD_CHAR_WIDTH + 1];

		if (menu == MENU_HOME)
		{
			sprintf(sBuf, "%3s %3ds %3d/%3d", (bIsRunning) ? "ON": "OFF", nShotInterval, nShotNumber, nMaxShots);
		}
		else if (menu == MENU_TIME)
		{
			sprintf(sBuf, "Time%3ds %3d/%3d", nShotInterval, nShotNumber, nMaxShots);
		}
		else
		{
			strcpy(sBuf, sMenu[nMenu]);
		}
		
		StrPadLCD(sBuf);

		return sBuf;
}


char*
GetDisplayProperty(int menu)
{
static  char    sBuf[LCD_CHAR_WIDTH + 1];	

	switch (menu)
	{
	case MENU_HOME:
	case MENU_TIME:
		sprintf(sBuf, "%s   %3dmin %3dmm", (bStepDirUP) ? "U": "D", nSpeedMinutes, nPositionMM);
		break;
	case MENU_INTERVAL:
		sprintf(sBuf, "%3d sec", nShotInterval); 
		break;
	case MENU_EXPOSURE:
		sprintf(sBuf, "%3d sec", nShotExposure); 
		break;
	case MENU_SHOTS:
		sprintf(sBuf, "%3d", nMaxShots);
		break;
	case MENU_POSITION:
		sprintf(sBuf, "%3d", nPositionMM);
		break;
	case MENU_STROKE:
		sprintf(sBuf, "%3d", nStroke);
		break;	
	case MENU_DIRECTION:
		strcpy(sBuf, (bStepDirUP) ? "UP": "DOWN");
		break;
	case MENU_DOLLY:
		strcpy(sBuf, (bModeDolly) ? "DOLLY": "STEP");
		break;
	case MENU_POWER:
		strcpy(sBuf, (bIsPowerSave) ? "SAVE": "OFF");
		break;
	case MENU_LCD:
		sprintf(sBuf, "%3d", nLCDBrightness);
		break;
	case MENU_MANUAL:
		sprintf(sBuf, "%3d", nPositionMM);
		break;
	default:
		strcpy(sBuf, "INVALID DISPLAY");
		break;
	}

	StrPadLCD(sBuf);

	return sBuf;
}

char*
StrPadLCD(char* sBuf)
{
	int	i;

	strlen(sBuf);
	for (i = strlen(sBuf); i < LCD_CHAR_WIDTH; i++)
	{
		sBuf[i] = ' ';
	}
	sBuf[LCD_CHAR_WIDTH] = '\0';

	return sBuf;
}


void
UpdateDisplay(void)
{
static	char	sLine1[LCD_CHAR_WIDTH + 1];
static	char	sLine2[LCD_CHAR_WIDTH + 1];
		char*	pLine1;
		char*	pLine2;

	pLine1 = GetDisplayName(nMenu);
	if (strcmp(pLine1, sLine1))
	{
		lcd.setCursor(0, 0);
		lcd.print(pLine1);
		strcpy(sLine1, pLine1);
	}

	pLine2 = GetDisplayProperty(nMenu);
	if (strcmp(pLine2, sLine2))
	{
		lcd.setCursor(0, 1);
		lcd.print(pLine2);
		strcpy(sLine2, pLine2);
	}
}


void
CmdProcess(int display, int cmd)
{

	switch (display)
	{
	case MENU_HOME:
		if (cmd == KEY_SELECT)
		{
			StopRunning();
		}
		else if (bIsRunning)
		{
			StopRunning();
		}
		else
		{
			StartRunning();
		}
		break;
	case MENU_INTERVAL:
		nShotInterval = CmdAdjust(nShotInterval, cmd, 1, 3600, 1, 1);
		nMaxShots = ((long)nSpeedMinutes * 60) / nShotInterval;
		if (nMaxShots > 999)
		{
			nMaxShots = 999;
		}
		break;
	case MENU_EXPOSURE:
		nShotExposure = CmdAdjust(nShotExposure, cmd, 1, 60, 1, 1);
		break;	
	case MENU_TIME:
		nSpeedMinutes = CmdAdjust(nSpeedMinutes, cmd, 3, 999, 10, nSpeedMinutes / 10 + 1);
		nMaxShots = ((long)nSpeedMinutes * 60) / nShotInterval;
		if (nMaxShots > 999)
		{
			nMaxShots = 999;
		}
		break;
	case MENU_SHOTS:
		nMaxShots = CmdAdjust(nMaxShots, cmd, 1, 999, 200, nMaxShots / 10 + 1);
		nSpeedMinutes = (nMaxShots * nShotInterval) / 60;
		break;
	case MENU_STROKE:
		nStroke = CmdAdjust(nStroke, cmd, 1, STROKE_MM, STROKE_MM, nStroke / 10 + 1);
		break;	
	case MENU_POSITION:
		nPositionMM = CmdAdjust(nPositionMM, cmd, 0, STROKE_MM, 0, nPositionMM / 10 + 1);
		break;
	case MENU_DIRECTION:
		bStepDirUP = !bStepDirUP;
		break;
	case MENU_DOLLY:
		bModeDolly = !bModeDolly;
		break;
	case MENU_POWER:
		bIsPowerSave = !bIsPowerSave;
		SetPowerSave();
		break;	
	case MENU_LCD:
		nLCDBrightness = CmdAdjust(nLCDBrightness, cmd, 20, 255, 50, 5);
		analogWrite(IO_LCD_BL, nLCDBrightness);
		break;
	case MENU_MANUAL:
		if (cmd == KEY_SELECT)
		{

		}
		else
		{
			motor_pulse_steps(1600, 200, (cmd == KEY_LEFT));
		}
		break;
	default:
		DebugTrace("ERROR INVALID DISPLAY\n");
		break;
	}
}


int
CmdAdjust(int value, int cmd, int min, int max, int def, int inc)
{

		switch (cmd)
		{
		case KEY_RIGHT:
			value += inc;
			if (value > max)
			{
				value = max;
			}
			break;
		case KEY_LEFT:
			value -= inc;
			if (value < min)
			{
				value = min;
			}
			break;
		case KEY_SELECT:
			value = def;
			break;
		}

		return value;
}


void
UserInterface(void)
{
	int	cmd;

	cmd = GetCmd();
  
	switch (cmd)
	{
		case KEY_UP:
			if (--nMenu < 0)
			{
				nMenu = NUM_MENU - 1;
			}
			break;
		case KEY_DOWN:
			if (++nMenu >= NUM_MENU)
			{
				nMenu = 0;
			}
			break;
		case KEY_RIGHT:
		case KEY_LEFT:
		case KEY_SELECT:
			CmdProcess(nMenu, cmd);
			break;
		case KEY_NULL:
			break;
		default:
			DebugTrace("ERROR INVALID CMD\n");
			break;
	} 
}


int
GetCmd(void)
{
static	unsigned long	lastDebounceTime;
static	unsigned long	valid_key_time;
static	int		lastread	= KEY_NULL;
		int		read;
		int		keyState;
		
		keyState = KEY_NULL;
		read = get_key();
		if (read != lastread)
		{
			lastDebounceTime = millis();
		}
		lastread = read;
 
		if (millis() - lastDebounceTime > KEY_DEBOUNC_MS)
		{
			keyState = read;

			lastread = KEY_NULL;
		}

		if (keyState != KEY_NULL)
		{
			valid_key_time = millis();
		}

			// dim the screen if no input
		if (millis() - valid_key_time > LCD_SCREENSAVE_TIME)
		{
				analogWrite(IO_LCD_BL, 20);
		}
		else
		{
				analogWrite(IO_LCD_BL, nLCDBrightness);
		}

		return keyState;
}

int 
get_key(void) 
{
static	int		adc_key_val[NUM_KEYS] = {30, 150, 360, 535, 760};
		int		k;
		int		input;
  
		input = analogRead(IOA_KEY_INPUT);
		for (k = 0; k < NUM_KEYS; k++) 
		{
			if (input < adc_key_val[k]) 
			{ 
				return k; 
			}
		} 
  
		return KEY_NULL;
}


void
StartRunning(void)
{

	bIsRunning = true;
	nShotNumber = 0;
	nNextShotNumber = 0;
	nPositionStep = (long) nPositionMM * STEPS_PER_MM;
	PreviousShotMS = millis();
}

void
StopRunning(void)
{
	bIsRunning = false;
}


void
DriveStepper(void)
{
 
	if (bModeDolly)
	{
		motor_pulse_steps_dolly();
	}
	else
	{
		if (nShotNumber == nNextShotNumber)
		{
			long	nSteps;
		
			nSteps = (long) nStroke * STEPS_PER_MM / nMaxShots;
			motor_pulse_steps_linear(nSteps);

			nNextShotNumber++;
		}
	}

}


void
motor_pulse_steps_dolly(void) // PATCH this should be via interrupt to keep going 
{
  long	nStep;
  long	nDelay;
  long	nStepPerSec;
  
  nStepPerSec = (long) nStroke * STEPS_PER_MM / 60 / nSpeedMinutes;
  nStep = nStepPerSec / ( 1000 / nCycleTimeMS);
  nDelay = 1000 / nStep * nCycleTimeMS;

  motor_pulse_steps(nStep, nDelay, bStepDirUP);
}

void
motor_pulse_steps(long nStep, long nDelay, boolean bDir)
{
  int	i;

  digitalWrite(IO_STEP_ENABLE, LOW);      // Enable the stepper motor
  digitalWrite(IO_STEP_DIR, (bDir) ? HIGH: LOW);    // set direction
  
  for (i = 0; i < nStep; i++)
  {
    digitalWrite(IO_STEP_STEP, HIGH);
    delayMicroseconds(1);
    digitalWrite(IO_STEP_STEP, LOW);
    delayMicroseconds(nDelay);
  }
  
  nPositionStep += (bDir) ? + nStep: - nStep;
  nPositionMM = nPositionStep / STEPS_PER_MM;
  
  SetPowerSave();
}

void 
motor_pulse_steps_linear(unsigned long steps) 
{
    
    // moving individual motors with a linear speed ramp
    // this speed ramp is used only to optimize torque,
    // minimize motor noise, missed steps, and prevent
    // excessive motion causes by a motor started and
    // stopped at full-speed.

  if (steps == 0)
    return;

  digitalWrite(IO_STEP_ENABLE, LOW);      // Enable the stepper motor
  digitalWrite(IO_STEP_DIR, (bStepDirUP) ? HIGH: LOW);    // set direction
  
    // shelf where motor speed ramp starts and stops
  unsigned long shelf_lo   = steps / 3;
  unsigned long shelf_hi   = shelf_lo * 2;
  
    // we can't have our ramp rate be zero, which it would be
    // if shelf_lo were >= the difference between min and max
    // ramp rate.  This happens when large moves (thousand+ steps)
    // try to use 1/3rd shelf up and down. So, reduce shelf
    // by ten percent until we get a reasonable range...
    
  while( shelf_lo >= ( motor_max_step - motor_min_step ) ) {
    shelf_lo = shelf_lo - ( (unsigned long) ( (float) shelf_lo * (float) 0.1 ) );
    shelf_hi = steps - shelf_lo;
  }
  
  unsigned int delay_increment = ( motor_max_step - motor_min_step ) / shelf_lo;
  unsigned int delay           = 0;
  
  for( long i = 0; i < steps ; i++ ) {

	digitalWrite(IO_STEP_STEP, HIGH);
    if( i < shelf_lo ) {
      
        // we're ramping up to speed 
      delay = ( delay_increment * ( shelf_lo - i ) ) + motor_min_step;
    }
    else if( i > shelf_hi ) {
        // we're ramping down from speed      
      delay = ( delay_increment * ( i - shelf_hi ) ) + motor_min_step;
    }
    else {
        // wer're moving at maximum speed
      delay = motor_min_step;
    }

    digitalWrite(IO_STEP_STEP, LOW);
    delayMicroseconds(delay);
    
  } // end for loop

	nPositionStep += (bStepDirUP) ? + steps: - steps;
	nPositionMM = nPositionStep / STEPS_PER_MM;

	SetPowerSave();
}


void
SetPowerSave(void)
{

	digitalWrite(IO_STEP_ENABLE, (bIsPowerSave) ? HIGH: LOW); // disable the power to stepper motor to save power.
}


void
FireCamera(void)
{
  unsigned long ms = millis();
 
  if (ms - PreviousShotMS > nShotInterval * 1000)
  {
    PreviousShotMS = ms;
	bShutterOpen = true;
	digitalWrite(IO_SHOT, HIGH);	// Fire the Shutter
  }
  else if (bShutterOpen)
  {
	  if (ms - PreviousShotMS > nShotExposure * 1000)
	  {
		digitalWrite(IO_SHOT, LOW);		// Release the Shutter
		bShutterOpen = false;

		if (++nShotNumber > nMaxShots)
		{
			DebugTrace("Maximum Shots\n");
			StopRunning();
		}
	  }
  }
}


void
CheckLimits(void)
{
  int  limit;
  
  limit = analogRead(IO_LIMIT_SWITCHES);
   if (480 < limit && limit < 540)  // SHOULD BE 512
   {
		DebugTrace("Limit RIGHT\n");
		StopRunning();
// PATCH change this to only stop if going this direction or cannot start on a limit.
   }
  else if (limit < 50)            // SHOULD BE 0
   {
		DebugTrace("Limit LEFT\n");
		StopRunning();
   }
  else                          // SHOULD BE 682
   {

   }
}


void
DebugTrace(char* sMsg)
{

	if (bDebug)
	{
		Serial.print(sMsg);
	}
}

Thank You