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mecharon
Joined: 09 Jun 2011
Posts: 3
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| Can't control 3 DC motors at the same time |
 Posted: Thu Jun 09, 2011 12:00 pm |
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Hi,
I'm a mech. eng. and beginner to electronic circuits and PIC programming.
I need to control of 3 DC motors' directions and positions via pulses taken from rotary encoders which connected to motors' shafts.
If I connect 1 motor to circuit I can control it's direction and position. But when I connect all of the motors, things are going different.
I'm sending, for example, 1A1A1A. This should have turn each of the motors anti-clockwise in direction and count the encoders of 65 pulses.
When I send 1A1A1A or 0A1A1A, first and third motor runs correctly. Second motor is running after waiting of 1 minute and stops. I can send another 6 byte string after that.
When I send 1A0A1A, first and second motor runs anti-clockwise, third motor runs clockwise. I can send another string.
It doesn't work if I send 0 as the third motor's direction. (1A1A0A or 0A0A0A)
I've read a lot of topics about this already, but couldn't make it worked.
Here's my code:
Any help would be appreciated.
| Code: |
#include <16F877.h>
#device adc=8
#FUSES NOWDT //No Watch Dog Timer
#FUSES HS //High speed Osc (> 4mhz)
#FUSES NOPUT //No Power Up Timer
#FUSES NOPROTECT //Code not protected from reading
#FUSES NOBROWNOUT //No brownout reset
#FUSES NOLVP //No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOCPD //No EE protection
#FUSES NOWRT //Program memory not write protected
#FUSES NODEBUG //No Debug mode for ICD
#use delay(clock=20000000)
#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7,STREAM=COM_A,timeout=10,parity=N,stop=1,bits=8) //DISABLE_INTS,timeout=10,parity=N,stop=1,bits=8
#byte TRISC=0x87
#byte TRISD=0x88
#byte PORTC=0x07
#byte PORTD=0x08
#bit MOTOR11=PORTC.0
#bit MOTOR12=PORTC.1
#bit MOTOR21=PORTC.2
#bit MOTOR22=PORTC.3
#bit MOTOR31=PORTC.4
#bit MOTOR32=PORTC.5
#bit ENC1=PORTD.0
#bit ENC2=PORTD.1
#bit ENC3=PORTD.2
int8 i=0, j=0, k=0,m=0;
char joker[10]={0,0,0,0,0,0,0,0,0,0};
int1 a1=0, b1=0, durum=0;
int1 a2=0, b2=0;
int1 a3=0, b3=0;
struct gorev{
int1 yon; //direction of the motor
int8 adim; //pulse count
};
struct gorev motor1={0,0};
struct gorev motor2={0,0};
struct gorev motor3={0,0};
#INT_RDA
void RDA_isr(void)
{
joker[m]=fgetc(COM_A);
putc(joker[m]);
m++;
}
void main()
{
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(SPI_SS_DISABLED);
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_1);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_ccp1(CCP_OFF);
setup_ccp2(CCP_OFF);
enable_interrupts(INT_RDA);
enable_interrupts(GLOBAL);
// TODO: USER CODE!!
TRISC=0b10000000;
TRISD=0b11111111;
PORTC=0b01000000;
PORTD=0b00000000;
while(1)
{
i=0;
j=0;
k=0;
durum=1;
while(m>5)
{
a1=0;b1=0;
a2=0;b2=0;
a3=0;b3=0;
if(durum==1)
{
motor1.yon=(joker[0]==0x31);
motor1.adim=joker[1];
motor2.yon=(joker[2]==0x31);
motor2.adim=joker[3];
motor3.yon=(joker[4]==0x31);
motor3.adim=joker[5];
durum=0;
}
if(i<motor1.adim)
{
a1=ENC1;
MOTOR11=motor1.yon;
MOTOR12=(!motor1.yon);
b1=ENC1;
i+=(b1!=a1);
}
else if(MOTOR11==MOTOR12)
{
}
else
{
MOTOR11=0;
MOTOR12=0;
}
if(j<motor2.adim)
{
a2=ENC2;
MOTOR21=motor2.yon;
MOTOR22=(!motor2.yon);
b2=ENC2;
j+=(b2!=a2);
}
else if(MOTOR21==MOTOR22)
{
}
else
{
MOTOR21=0;
MOTOR22=0;
}
if(k<motor3.adim)
{
a3=ENC3;
MOTOR31=motor3.yon;
MOTOR32=(!motor3.yon);
b3=ENC3;
k+=(b3!=a3);
}
else if(MOTOR31==MOTOR32)
{
}
else
{
MOTOR31=0;
MOTOR32=0;
}
if(i>=motor1.adim && j>=motor2.adim && k>=motor3.adim)
{
putc('T');
m=0;
}
} //while m>5
} //while 1
}
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Circuit:
Proteus screenshot:
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mecharon
Joined: 09 Jun 2011
Posts: 3
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| Posted: Mon Jun 13, 2011 6:02 am |
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| I'm still stuck on it. Any thoughts? |
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temtronic
Joined: 01 Jul 2010
Posts: 9225
Location: Greensville,Ontario
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| Posted: Mon Jun 13, 2011 7:48 am |
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Lots of thought..quickly..
1) get rid of the tris..... commands. Let the compiler handle the 'details' as ONE wrong setting on your part can cause a LOT of weird problems.
2) add 'errors' to the use RS232(...) function.it'll keep the serial port working correctly.
3) confirm that each motor works right invididually. Then add a second motor and confirm, then the third.Perhaps the 'control' byte that you're sending to the motor drivers is a bit wrong ?
4) this 1A1A.... commands. Is that data from the serial port ? If so, see #2 above. Hard code the program to test all the motors to confirm it's a PC communications problem and NOT the actual command to the motors.
5) display the received commands onto the LCD on line 1 to verify what you got and display the motor command on line 2. This will show you what is really happening instead of 'well it should be....'. |
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mecharon
Joined: 09 Jun 2011
Posts: 3
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| Posted: Tue Jun 14, 2011 7:31 am |
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Thank you for your reply.
I tried all of your advices and saw that the code is working correctly, but circuit still isn't. Then I decided to destroy the circuit. I took it, then started to bending... It suddenly started to working as it's meant to be. Problem is a soldering connection fault.  |
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temtronic
Joined: 01 Jul 2010
Posts: 9225
Location: Greensville,Ontario
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| Posted: Tue Jun 14, 2011 7:40 am |
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Glad you found the cause to all your grief! I once had a 'looked good 'solder joint fail after 4 years of harsh service.even under a magnfying glass is loloked good,but cold spray finally should a micro fracture.2 seconds of heat to resolder and it was cured.
It's not always the software that's at fault !! |
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