ISR for PWM to RC servo - button

[Kryten]

Hi
I have a litte troubble with this code. Icant get it to work properly.
Most of the code is from a turtorial where youre supposed to use adc (ch 1 and 2) for input to control the servo (for LDR, turing left or right).
I was thinking it could be adapted for buttons for left and right but i guess I changed/ added worng thing

/////////////////////////////////////////////////////
//                                                             //
//     Servo with Interupt                            //
/////////////////////////////////////////////////////

#include <p18f4550.h>
//#include <adc.h>
#include <delays.h>

///////////////////////////////////////////////////////////////
// Config bits                                                          //
///////////////////////////////////////////////////////////////

#pragma config PLLDIV = 5			// This value has to be 5 for 20Mhz xtal as PLL accepts fixed input of 4MHz only
#pragma config USBDIV = 2			// Clock source from 96MHz PLL/2, therefore USB clock is 48MHz in full speed
#pragma config FOSC   = HSPLL_HS	// HS oscillator, PLL enabled
#pragma config CPUDIV = OSC4_PLL6	// 96MHz PLL Src/6 => a CPU clock of 16MHz achieved for Vdd=3.3V
#pragma config PWRT   = ON			// PowerUp timer ON
#pragma config WDT    = OFF			// watchdog timer off
#pragma config LVP    = OFF			// low level voltage progamming OFF
#pragma config BOR    = OFF			// brown out detect off
#pragma config DEBUG  = ON			// Debug ON
#pragma config PBADEN = OFF 		// PORTB<4:0> as digital IO on reset
#pragma config STVREN = ON  		// Stack overflow reset ON
#pragma config VREGEN = OFF			// Disable internal 3.3V regulator!
#pragma config MCLRE  = ON			// Enable MCLRE for reset function

///////////////////////////////////////////////////////////
// Defines                                               //
///////////////////////////////////////////////////////////

#define TRUE               (1)
#define FALSE              (0)
#define MAX_TIMER_SERVO    (64536)             // Far left position 
#define MIN_TIMER_SERVO    (62086)             // Far right position
#define CENTER_TIMER_SERVO (63456)             // Center servo position
#define SERVO_STEP         (10)                // Servo precision
#define PORT_TURN_LEFT     (PORTCbits.RC1)     // Button for left
#define PORT_TURN_RIGHT    (PORTCbits.RC2)     // Button for right
#define PORT_RED_LED       (PORTCbits.RC6)     // Red led to test input
#define PORT_GREEN_LED     (PORTCbits.RC7)     // Green led to test input

unsigned int timerServo;                       // global variable

void YourHighPriorityISRCode ();
void YourLowPriorityISRCode ();

////////////////////////////////////////////////////
//  ISR routine                                   //
////////////////////////////////////////////////////

#pragma code high_vector = 0x08
void high_vector ()
	{
	_asm 
	goto YourHighPriorityISRCode
	_endasm
	}
#pragma code

#pragma code low_vector = 0x18
void low_vector()
	{
	_asm 
	goto YourLowPriorityISRCode
	_endasm
	}
#pragma code

// interupt handel routines
#pragma interrupt YourHighPriorityISRCode
void YourHighPriorityISRCode ()
{
	if(PIR1bits.TMR1IF == TRUE)                  // check interrupt flag from timer0
	{
		if(PORTBbits.RB5 == 0)
			{
			TMR1H = (timerServo & 0xFF00) >> 8; // Keep MSB
			TMR1L = timerServo & 0x00FF;        // Keep LSB
			PORTBbits.RB5 = 1;                  // high pulse
			}
		else
			{
			TMR1H = 0x8A;                      // Timer interups after 83.3ns*8*(65536-35536) = +/- 20 ms
			PORTBbits.RB5 = 0;                  // low pulse
			}
		PIR1bits.TMR1IF = FALSE;               //reenable TMR1 interrupt
	}	
}

#pragma interruptlow YourLowPriorityISRCode
void YourLowPriorityISRCode()
{
}



////////////////////////////////////////////////////////
// Main routine                                       //
////////////////////////////////////////////////////////

void main (void)
{
TRISBbits.TRISB5 = 0;                          //set RB5 as output
PORTBbits.RB5 = 0;                             //Initialize with 0
TRISCbits.TRISC1 = 1;                          //Set RC1 as input
PORTCbits.RC1 = 0;
TRISCbits.TRISC2 = 1;                          //Set RC2 as input
PORTCbits.RC2 = 0;
TRISCbits.TRISC6 = 0;                          //Set RC6 as output
PORTCbits.RC6 = 0;
TRISCbits.TRISC7 = 1;                          //Set RC6 as output
PORTCbits.RC7 = 0;
timerServo = CENTER_TIMER_SERVO;               // Max right
PIR1bits.TMR1IF = 0;                           // Setting timer to 0
RCONbits.IPEN = 1;                             //Activating High prioity interrupt
//RCONbits.SBOREN = 0;                           // BOR = off
T1CON = 0b0011001;                             // 48Mhz/4, prescaler 1/8
INTCON = 0b10000000;                           // GIEH = TRUE
IPR1bits.TMR1IP = 1;
PIE1bits.TMR1IE = 1;

while (1)
	{
	if (PORT_TURN_LEFT = 1)
	{
	PORT_RED_LED = 1;
	PORT_GREEN_LED = 0;
	timerServo = (timerServo - SERVO_STEP);
	}
	if (PORT_TURN_RIGHT = 1)
	{
	PORT_GREEN_LED = 1;
	PORT_RED_LED = 0;
	timerServo =(timerServo + SERVO_STEP);
	}

/*	if (timerServo > MAX_TIMER_SERVO)
	{
	timerServo = MAX_TIMER_SERVO;
	}
	if (timerServo < MIN_TIMER_SERVO)		
	{
	timerServo = MIN_TIMER_SERVO;
	}*/
	else
	{
	timerServo = CENTER_TIMER_SERVO;
	}
	Delay10KTCYx(6);                           // Wait 5ms
}
}

If somebody that knows a bit more (or a lot more) than me about ISR. I would be rally thankful for some tips/help on how to get it working properly..



Im using 20MHz clk so Im thinking I might be off

 

[3v0]

Time for 60 lashes with a wet noodle !

If you are going to use C you have to learn the language and that means more then copying code from other people.

One obvious problem is that you do not know the difference between the assignment operator = and the conditional test ==

In your code

if (PORT_TURN_LEFT [COLOR=Red]= [/COLOR]1)

Because PORT_TURN_LEFT is #defined as
PORTCbits.RC1, this attempts to make RC1 high.

What you want is the test for equality ==

if (PORT_TURN_LEFT [COLOR=Red]==[/COLOR] 1)

I did not look any further.

This grumpy old man thinks that ISR's are way over
your head.

 

[Pommie]

Here's a version that doesn't use interrupts. There's also an interrupt version further down the thread.

Mike.

 

[Kryten]

Thanks Mike. The Grumpy old man said somethings that i dont like (see he has edited it out) Yes ISR is over my head but if I dont try it will always be there