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Fruppy
Joined: 27 May 2021
Posts: 5
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| Encoder motor control |
 Posted: Thu May 27, 2021 4:08 pm |
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Hi everyone. I have a problem. I wanna find angle but I couldn't find.
I don't know where is my mistakes. I need help. My code are below:
| Code: |
#include <16F877A.h>
#device adc=10 //set the bit value of adc
#FUSES XT, NOWDT, NOPROTECT, NOBROWNOUT, NOLVP, NOPUT, NODEBUG, NOCPD
#use delay(crystal=4000000)
#include <lcd.c>
#INT_RB // RB port interrupt on change
int8 last_read;
int8 quad;
void RB_IOC_ISR(void)
{
int8 encoderRead;
clear_interrupt(INT_RB);
encoderRead = input_b() & 0x30;
if(encoderRead == last_read)
return;
if(bit_test(encoderRead, 4) == bit_test(last_read, 5))
quad -= 1;
else
quad += 1;
last_read = encoderRead;
}
signed long EncoderGet(void)
{
signed long value = 0;
while(quad >= 4){
value += 1;
quad -= 4;
}
while(quad <= -4){
value -= 1;
quad += 4;
}
return value;
}
unsigned long change = 0;
unsigned long realPosition = 0;
unsigned long angle = 0.0f;
void main()
{
unsigned long int8 pwm;
unsigned int16 rev;
unsigned long int16 referance; //variable for ADC reading value from AN0
unsigned int16 kp; //variable for ADC reading value from AN1
lcd_init();
delay_ms(10);
set_tris_c(0x00); //set all portb pins as output
setup_ccp1(CCP_PWM); //4kHz PWM signal output at CCP1 pin 17
setup_ccp2(CCP_PWM); //4kHz PWM signal output at CCP2 pin 16
setup_timer_2(T2_DIV_BY_16, 255, 1);
setup_adc_ports(ALL_ANALOG); //A0A1 A2 A3 A5 E0 E1 E2 analog pins
setup_adc(ADC_CLOCK_DIV_32); //enable ADC and set clock FOR ADC
while(true)
{
set_adc_channel(0); // next analog reading will be from channel 0
delay_us(10); //allow time after channel selection and reading
referance= read_adc(); //start and read A/D
referance= referance*250;
referance= referance/1023;
referance= referance+20;
printf(LCD_PUTC,"\fRef=%lu,",referance); //print ADC value FOR A0
set_adc_channel(1); // next analog reading will be from channel 1
delay_us(10); //allow time after channel selection and reading
kp = 50+(read_adc()*10/1023); //start and read A/D
printf(LCD_PUTC,"Kp=%lu",kp); //print ADC value FOR A1
delay_ms(200);
change = EncoderGet();
if(change)
{
realPosition += change;
}
rev = realPosition/360.0f; // Here 360 represents the encoder pulses per revolution
angle = ((int16)(rev*360))%360; // Real time angle is determined in this line
printf(LCD_PUTC,"\nPos=%lu,",angle);
delay_ms(700);
pwm= kp*(referance-angle);
set_pwm1_duty(pwm); //set pulse-width during which signal is high
printf(LCD_PUTC,"Pwm=%lu",pwm);
delay_ms(700);
}
} |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Re: Encoder motor control |
| Posted: Thu May 27, 2021 4:30 pm |
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Make the changes shown in bold below.
| Fruppy wrote: |
#include <16F877A.h>
#device adc=10 //set the bit value of adc
#FUSES XT, NOWDT, NOPROTECT, NOBROWNOUT, NOLVP, NOPUT, NODEBUG, NOCPD
#use delay(crystal=4000000)
#include <lcd.c>
#INT_RB // Wrong location for this line
int8 last_read;
int8 quad;
#INT_RB // Move it to here
void RB_IOC_ISR(void)
{
int8 encoderRead;
clear_interrupt(INT_RB); // This line is not needed.
encoderRead = input_b() & 0x30;
if(encoderRead == last_read)
return;
if(bit_test(encoderRead, 4) == bit_test(last_read, 5))
quad -= 1;
else
quad += 1;
last_read = encoderRead;
}
void main()
{
unsigned int8 temp;
unsigned long int8 pwm;
unsigned int16 rev;
unsigned long int16 referance; //variable for ADC reading value from AN0
unsigned int16 kp; //variable for ADC reading value from AN1
lcd_init();
delay_ms(10);
set_tris_c(0x00); //set all portb pins as output. Your comment does not match the port
temp = input_b(); // Add these 4 lines
enable_interrupts(INT_RB);
clear_interrupt(INT_RB);
enable_interrupts(GLOBAL);
setup_ccp1(CCP_PWM); //4kHz PWM signal output at CCP1 pin 17
setup_ccp2(CCP_PWM); //4kHz PWM signal output at CCP2 pin 16
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Additional changes may be needed if you are using PortB for
anything other than the two interrrupt on change pins. |
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Fruppy
Joined: 27 May 2021
Posts: 5
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| Posted: Fri May 28, 2021 3:51 am |
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Nothing has changed. The position is always 0. It should normally approach and equalize the reference value.
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temtronic
Joined: 01 Jul 2010
Posts: 9135
Location: Greensville,Ontario
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| Posted: Fri May 28, 2021 4:21 am |
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Is this real hardware or a simulation ?
Print out every intermediate calculation to be 100% sure you don't have a 'math' or 'casting' error.
Use scaled integers instead of floating point. S-Int are more accurate and 10-20x faster.
Last edited by temtronic on Fri May 28, 2021 4:31 am; edited 1 time in total |
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Fruppy
Joined: 27 May 2021
Posts: 5
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| Posted: Fri May 28, 2021 4:26 am |
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| It is a simulation. |
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temtronic
Joined: 01 Jul 2010
Posts: 9135
Location: Greensville,Ontario
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| Posted: Fri May 28, 2021 4:36 am |
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please read PIC101...
It is very well known that Proteus does NOT function 100% ! Even the simplest 'schematic' will NOT work as drawn, in the 'real World'.
I do KNOW that an 877 does run PID controller very, very well. Had real helicopters with 3 axis, 1024 encoders and servo motor in them 20 years ago. |
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Fruppy
Joined: 27 May 2021
Posts: 5
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| Posted: Fri May 28, 2021 4:46 am |
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This is my project. I used 877.
The circuit is as in the picture below:
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri May 28, 2021 8:06 am |
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Post your latest program so we can see if you made the changes.
Also, why are you mixing data types as shown below in bold ?
| Quote: | unsigned long int8 pwm;
unsigned int16 rev;
unsigned long int16 referance;
unsigned int16 kp;
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A 'long int8' is the same as int16, so why not just use int16 ?
A 'long int16' is the same as int32, so why not just use int32 ? |
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Fruppy
Joined: 27 May 2021
Posts: 5
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| Posted: Fri May 28, 2021 8:40 am |
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I'm new to coding, so I didn't know that long int16 and int32 mean the same thing. Code is below
| Code: |
#include <16F877A.h>
#device adc=10 //set the bit value of adc
#FUSES XT, NOWDT, NOPROTECT, NOBROWNOUT, NOLVP, NOPUT, NODEBUG, NOCPD
#use delay(crystal=4000000)
#include <lcd.c>
int8 last_read;
int8 quad;
#INT_RB // RB port interrupt on change
void RB_IOC_ISR(void)
{
int8 encoderRead;
encoderRead = input_b() & 0x30;
if(encoderRead == last_read)
return;
if(bit_test(encoderRead, 4) == bit_test(last_read, 5))
quad -= 1;
else
quad += 1;
last_read = encoderRead;
}
signed long EncoderGet(void)
{
signed long value = 0;
while(quad >= 4){
value += 1;
quad -= 4;
}
while(quad <= -4){
value -= 1;
quad += 4;
}
return value;
}
unsigned long change = 0;
unsigned long realPosition = 0;
unsigned long angle = 0.0f;
void main()
{
unsigned int8 temp;
unsigned int16 pwm;
unsigned int16 rev;
unsigned int32 referance; //variable for ADC reading value from AN0
unsigned int16 kp; //variable for ADC reading value from AN1
lcd_init();
delay_ms(10);
set_tris_c(0x00); //set all portc pins as output
temp = input_b();
enable_interrupts(INT_RB);
clear_interrupt(INT_RB);
enable_interrupts(GLOBAL);
setup_ccp1(CCP_PWM); //4kHz PWM signal output at CCP1 pin 17
setup_ccp2(CCP_PWM); //4kHz PWM signal output at CCP2 pin 16
setup_timer_2(T2_DIV_BY_16, 255, 1);
setup_adc_ports(ALL_ANALOG); //A0A1 A2 A3 A5 E0 E1 E2 analog pins
setup_adc(ADC_CLOCK_DIV_32); //enable ADC and set clock FOR ADC
while(true)
{
set_adc_channel(0); // next analog reading will be from channel 0
delay_us(10); //allow time after channel selection and reading
referance= read_adc(); //start and read A/D
referance= referance*250;
referance= referance/1023;
referance= referance+20;
printf(LCD_PUTC,"\fRef=%lu,",referance); //print ADC value FOR A0
set_adc_channel(1); // next analog reading will be from channel 1
delay_us(10); //allow time after channel selection and reading
kp = 50+(read_adc()*10/1023); //start and read A/D
printf(LCD_PUTC,"Kp=%lu",kp); //print ADC value FOR A1
delay_ms(200);
change = EncoderGet();
if(change)
{
realPosition += change;
}
rev = realPosition/360.0f; // Here 360 represents the encoder pulses per revolution
angle = ((int16)(rev*360))%360; // Real time angle is determined in this line
printf(LCD_PUTC,"\nPos=%lu,",angle);
delay_ms(700);
pwm = kp*(referance-angle);
set_pwm1_duty(pwm); //set pulse-width during which signal is high
if(pwm>1023){
pwm=1023;
}
if(pwm<0){
pwm=0;
}
printf(LCD_PUTC,"Pwm=%lu",pwm);
delay_ms(700);
}
}
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri May 28, 2021 5:50 pm |
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A few more problems:
| Fruppy wrote: |
#use delay(crystal=4000000)
setup_adc(ADC_CLOCK_DIV_32);
while(true)
{
set_adc_channel(0);
delay_us(10); // Should be 20 usec delay
set_adc_channel(1);
delay_us(10); // Should be 20 usec delay
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The 16F877A data sheet says that for a 4 MHz PIC oscillator
frequency, the ADC clock divisor should be 8. Change the
setup_adc() statement to be:
| Code: |
setup_adc(ADC_CLOCK_DIV_8);
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The data sheet also says the ADC acquisition time is 19.72 us.
You should change each of the delay_us(10) statements to be:
I compiled your latest program. I got these warnings:
| Quote: | >>> Warning 204 Line 30(1,1): Condition always FALSE
>>> Warning 205 Line 90(1,1): Unsigned variable is never less than zero
>>> Warning 204 Line 90(1,1): Condition always FALSE
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You need to fix these problems. |
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temtronic
Joined: 01 Jul 2010
Posts: 9135
Location: Greensville,Ontario
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| Posted: Sat May 29, 2021 6:45 am |
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I don't see any control over IN1,IN2 of the L298 so there's NO directional control, possibly the motor won't spin....
Also since PWM register is just 0-1023, you don't need signed values to control it( the 'math' ) |
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