Variable corrupted when sharing in main/isr using C18

[sugus]

Hi guys,

I've got a problem with the "enc_a_value". I've written a simple code to test some functionalities of my design. My goal is to turn on a motor in forward direction for 500 encoder pulses. When it reaches that position, stop it and after a delay, turn it back in the reverse direction for 500 pulses again.

The problem is that when I clear "enc_a_value" on main, I can see that it is correctly cleared, but when it jumps again to the Servo Isr (where enc_a_value is updated), this variable takes it's old value again (500).

I'm using C18 v.2.30 demo and MPLAB 7.30. I tried to disable interrupts when updating the variable in main, and adding "-v" to compiler settings, but still not works.

I will be grateful with any suggest.

Regards.


#include <p18cxxx.h>
#include <math.h>
#include <timers.h>
#include <pwm.h>

#typedef unsigned int PWM;

volatile float j = 0;
volatile unsigned int enc_a_value = 0;
volatile unsigned int enc_b_value = 0;
volatile unsigned int encoder_tmp = 0;


void interrupt_at_high_vector(void);
void servo_isr(void);
void delay(void);
void init_timers(void);
void config_ports(void);
void azimuth_motor_forward(PWM azimuth_duty);
void azimuth_motor_reverse(PWM azimuth_duty);
void elevation_motor_forward(PWM elevation_duty);
void elevation_motor_reverse(PWM elevation_duty);
void azimuth_motor_fast_stop(void);
void elevation_motor_fast_stop(void);



#pragma config WDT = OFF

#pragma code high_vector = 0x08
void interrupt_at_high_vector(void)

{
_asm
goto servo_isr
_endasm
}
#pragma code
#pragma interrupt servo_isr
void servo_isr(void){

PIR1bits.TMR1IF = 0; // resets Timer1 interruption flag
WriteTimer1(0xACAF); // TMR1 start counting value

enc_a_value = TMR3L; // Encoder A value refresh from
encoder_tmp = TMR3H; // Timer 3 asynchronous counter
encoder_tmp = (encoder_tmp << 8); //
enc_a_value = encoder_tmp + enc_a_value; //

enc_b_value = TMR0L; // Encoder A value refresh from
encoder_tmp = TMR0H; // Timer 0 asynchronous counter
encoder_tmp = (encoder_tmp << 8); //
enc_b_value = encoder_tmp + enc_b_value; //
}

void delay (void)
{
double i;


for (i = 0; i < 1000; i++)
{
j = sin(rand());
}

}

void config_ports (void)
{

TRISA = 111111;
TRISB = 11001000;
TRISC = 00000001;
TRISD = 00000011;
TRISE = 00000000;

}

void init_timers (void)
{

OpenTimer0(TIMER_INT_OFF & T0_16BIT & T0_SOURCE_EXT & T0_EDGE_RISE); // ENCODER B CONFIG
OpenTimer1(TIMER_INT_ON & T1_16BIT_RW & T1_SOURCE_INT & T1_PS_1_1 & T1_OSC1EN_OFF & T1_SYNC_EXT_OFF ); // SERVO
OpenTimer2(TIMER_INT_OFF & T2_PS_1_4 & T2_POST_1_1); // PWM
OpenTimer3(TIMER_INT_OFF & T3_16BIT_RW & T3_SOURCE_EXT & T3_PS_1_1 & T3_SYNC_EXT_ON & T1_CCP1_T3_CCP2); // ENCODER A CONFIG
WriteTimer1(0xACAF);
}

void azimuth_motor_forward(PWM azimuth_duty)
{
SetDCPWM1 (azimuth_duty); // Sets PWM1 duty cycle
PORTBbits.RB0 = 0;
PORTBbits.RB1 = 1; // TMR1 start counting value
}

void azimuth_motor_reverse (PWM azimuth_duty)
{
SetDCPWM1 (azimuth_duty); // Sets PWM1 duty cycle
PORTBbits.RB0 = 1;
PORTBbits.RB1 = 0;
}

void elevation_motor_forward (PWM elevation_duty)
{
SetDCEPWM1 (elevation_duty); // Sets PWM2 duty cycle
PORTEbits.RE0 = 0;
PORTEbits.RE1 = 1;
}


void elevation_motor_reverse (PWM elevation_duty)
{
SetDCEPWM1 (elevation_duty); // Sets PWM2 duty cycle
PORTEbits.RE0 = 1;
PORTEbits.RE1 = 0;
}

void azimuth_motor_fast_stop (void)
{
PORTBbits.RB0 = 1;
PORTBbits.RB1 = 1;
}

void elevation_motor_fast_stop (void)
{
PORTEbits.RE0 = 1;
PORTEbits.RE1 = 1;
}

void main (void)
{

_asm
MOVLW 0X0A //
MOVWF 0x0FC1, 0 // configure ADcon1 peripheral
_endasm

config_ports();
init_timers();
INTCONbits.GIE = 1; // Enables Global Interrupt bit
INTCONbits.PEIE = 1; // Enables Peripheral Interrupt bit

OpenPWM1 (0x28); // Sets PWM1 period
OpenEPWM1 (0x28); // Sets PWM2 period


while(1){

while (enc_a_value < 0x500){
azimuth_motor_forward(0x50);
elevation_motor_forward(0x50);
INTCONbits.GIE = 0; // Disables Global Interrupt bit
PORTCbits.RC7 = 1;
PORTCbits.RC6 = 0;
INTCONbits.GIE = 1; // Enables Global Interrupt bit
}
azimuth_motor_fast_stop();
elevation_motor_fast_stop();
INTCONbits.GIE = 0; // Disables Global Interrupt bit
enc_a_value = 0;
enc_b_value = 0;
INTCONbits.GIE = 1; // Enables Global Interrupt bit

delay();

while (enc_a_value < 0x500){
azimuth_motor_reverse(0x50);
elevation_motor_reverse(0x50);
PORTCbits.RC7 = 1;
PORTCbits.RC6 = 1;
}
azimuth_motor_fast_stop();
elevation_motor_fast_stop();
INTCONbits.GIE = 0; // Disables Global Interrupt bit
enc_a_value = 0;
enc_b_value = 0;
INTCONbits.GIE = 1; // Enables Global Interrupt bit
delay();

///////////////////////////////


while (enc_a_value < 0x500){
azimuth_motor_forward(0xE5);
elevation_motor_forward(0xE5);
PORTCbits.RC7 = 1;
PORTCbits.RC6 = 0;
}
azimuth_motor_fast_stop();
elevation_motor_fast_stop();
INTCONbits.GIE = 0; // Disables Global Interrupt bit
enc_a_value = 0;
enc_b_value = 0;
INTCONbits.GIE = 1; // Enables Global Interrupt bit
delay();

while (enc_a_value < 0x500){
azimuth_motor_reverse(0xE5);
elevation_motor_reverse(0xE5);
PORTCbits.RC7 = 0;
PORTCbits.RC6 = 1;
}

azimuth_motor_fast_stop();
elevation_motor_fast_stop();
INTCONbits.GIE = 0; // Disables Global Interrupt bit
enc_a_value = 0;
enc_b_value = 0;
INTCONbits.GIE = 1; // Enables Global Interrupt bit
delay();
} //end while(1)
}//end main()

[Ttelmah]

This is _not_ a C18 forum, but a CCS forum. Rewrite it in CCS C, and somebody here may well be able to help you, but if you want to ask a C18 question, you'd better go onto one of the C18 forums...

Best Wishes

[treitmey]

I have a question about a 55' triumph TR2 long door.

How do you tune the SU carbs?


My attempt at dry humor
Duh. The big CCS at the top of the forum didn't give him a clue?

[sugus]

Thanks both for your humor.

If some day CCS provides a real 18-family compiler, I will seriously think about using it.

[ccsc very good]

you're blind

it's only discrepancy in ability

[dyeatman]

I (and many others here) have used the "real" CCS family compiler in many commercial/Industrial projects and it has done the job. Bugs are present in every compiler INCLUDING C18. Please don't come here as a C18 user and down the CCS product. If you don't have CCS and/or nothing good to say, how about going to the C18 forum with your C18 questions and comments. I don't go to the C18 forum and down them....

[Guest]

[Guest]