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vietlongIPD
Joined: 16 Mar 2010
Posts: 1
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| help- impulse noise encoder - pic 18f4331 - use int ext |
 Posted: Tue Mar 16, 2010 8:50 am |
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Hi everybody
I have a strange problem. I control my motor (servo with encoder 200 slot - 2 sign A B) with module ccp1 and I use int_ext1 (PIN_C4) to receive signA of encoder. But if I don't connect supply power for motor (one pole connect with +12v, other pwm1 = ccp1) program recognize correct number of pulse encoder and if have motor run program is wrong, same have noise. PIC auto count pulse and perform program although I don't rotate encoder (I take apart the motor & encoder).
Here is my circuit, assured that there is no virus ( orcad 10.5)
http://www.mediafire.com/?mjmjm5w3myv
My program
| Code: |
#include <18f4331.h>
#FUSES HS //High speed Osc (> 4mhz)
#FUSES PUT //Power Up Timer
#FUSES NOPROTECT //Code not protected from reading
#FUSES NOBROWNOUT //No brownout reset
#FUSES NOLVP //Low Voltage Programming on B3(PIC16) or B5(PIC18)
#FUSES NOCPD //No EE protection
#FUSES NODEBUG //No Debug mode for ICD
#FUSES NOWDT
#use delay(clock=20000000)
#use fast_io(b)
#use fast_io(c)
#use fast_io(a)
#use fast_io(d)
#use fast_io(e)
int1 flag_ngat1=0,flag_ngat2=0,ngat1=0,ngat2=0;
int16 signA,signB,en_t,en_p;
int8 en;
/**************************************/
#int_ext1 //count encoder left
void ngat_int1()
{
disable_interrupts(int_ext1);
signA++;
if ((signA >= en_t)&&(flag_ngat1 == 0))
{
ngat1 = 1;
flag_ngat1 = 1;
signA = 0;
}
enable_interrupts(int_ext1) ;
}
#int_ext2 //count encoder right
void ngat_int2()
{
disable_interrupts(int_ext2);
signB ++;
if ((signB >= en_p)&&(flag_ngat2 == 0))
{
ngat2 = 1;
flag_ngat2 = 1;
signB = 0;
}
enable_interrupts(int_ext2) ;
}
/**************************************/
void main(){
set_tris_A(0xB1); // pin A7 -> pin A0 1011 0001
set_tris_B(0xC0); // pin B7 -> pin B0 1100 0000
set_tris_C(0x39); // pin C7 -> pin C0 0011 1001
set_tris_D(0x03); // pin D7 -> pin D0 0000 0011
set_tris_E(111);
setup_ccp1(CCP_PWM);
setup_ccp2(CCP_PWM);
setup_timer_0( RTCC_INTERNAL| RTCC_DIV_256 | RTCC_8_BIT);
setup_timer_2(T2_DIV_BY_16, 255, 1);
/* setup_power_pwm_pins(PWM_BOTH_ON,PWM_BOTH_ON,PWM_O FF,PWM_OFF);
setup_power_pwm(PWM_CLOCK_DIV_128|PWM_FREE_RUN,
1, //postscale, not used
0, //initial PTMR
63, //**************PTPER9 //
0, //compare special event, not used
1, //postscale compare special event, not used
0); //dead_time
set_power_pwm_override(1, false, 0);
set_power_pwm_override(3, false, 0);
set_power_pwm_override(5, false, 0);
set_power_pwm_override(7, false, 0);*/ // use mode PWM cua 18f4331
enable_interrupts(int_ext1);
enable_interrupts(int_ext2);
ext_int_edge(1, L_TO_H );
ext_int_edge(2, L_TO_H );
enable_interrupts(GLOBAL);
output_high(PIN_B0);
output_high(PIN_B1);
output_high(PIN_B2);
output_high(PIN_B3);
output_high(PIN_B4);
output_high(PIN_B5);
output_high(PIN_D2);
output_high(PIN_D3);
output_high(PIN_D4);
output_high(PIN_D5);
output_high(PIN_D6);
output_high(PIN_D7);
output_high(PIN_C6);
output_high(PIN_C7);
set_pwm1_duty(255); //high V on CCP1
set_pwm2_duty(255); //high V on CCP2
signA=0
while(true){
if(signA>100) output_low(PIN_B0); //if encoder rotate 1 round then indicator light of Pin B0 lighted
if(signA>200) output_low(PIN_B1); //if encoder rotate 2 round then indicator light of Pin B2 lighted
if(signA>300) output_low(PIN_B2); //if encoder rotate 3 round then indicator light of Pin B0 lighted
if(signA>400) output_low(PIN_B3); //if encoder rotate 4 round then indicator light of Pin B0 lighted
if(signA>500) output_low(PIN_B4); //if encoder rotate 5 round then indicator light of Pin B0 lighted
}
}
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This is simple program for test encoder but as I said, if I connect motor with CCP1 and run it -> my program auto light lamp although I don't rotate encoder. I don't know why (of course pin 17 ccp1 connect - octo - uln2803 - bjtb562 // d468 - mosfet irf540 - 1pole of motor) .
My friend advise me to use module QEi for filter noise but I don't know how to config module QEI - somebody can help me - I fabricate one robot and I need use encoder --> for control the motor and calculate distance of the robot correctly.
Sorry for my English level is not very good, but I hope that you can understand a little piece and help me.
Best regards. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Mar 16, 2010 4:15 pm |
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| Quote: |
PIC auto count pulse and perform program although I don't rotate encoder
enable_interrupts(int_ext1);
enable_interrupts(int_ext2);
ext_int_edge(1, L_TO_H );
ext_int_edge(2, L_TO_H );
enable_interrupts(GLOBAL);
|
Does the encoder have open-collector outputs ? (or open-drain)
If it does, then the PIC interrupt pins will be "floating" inputs.
This means an interrupt could be triggered by noise at any time.
To fix this, you need to use pull-up resistors on the INT0 and INT1 pins
on the PIC. You can use 4.7K ohms. This will hold the INT0 and INT1
pins at a logic '1' level, and prevent interrupts due to noise.
| Quote: |
set_tris_A(0xB1); // pin A7 -> pin A0 1011 0001
set_tris_B(0xC0); // pin B7 -> pin B0 1100 0000
set_tris_C(0x39); // pin C7 -> pin C0 0011 1001
set_tris_D(0x03); // pin D7 -> pin D0 0000 0011
set_tris_E(111);
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Also, the '111' value is probably not intended. You probably mean 0b111
or 0x07. |
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