L298N Motor Driver using pwm code not working..

[HenrikOlsson]

That code looks just wrong.
You set four outputs on PortD while the schematic shows PortC.
Then you seems to missing the actual PWM statement, and if you meant to PWM the Enable pins you have those too on the wrong pins.

I'm surprised if that code even compiles.

/Henrik.

[tacbanon]

Hi Henrik,
My bad, uploaded the wrong image(must be very tired last night)
[ATTACH=CONFIG]6686[/ATTACH
Thanks for the replying...I will try it today and post here my output.

and if you meant to PWM the Enable pins you have those too on the wrong pins.

..aren't pin5 and pin6 the PWM pins on JP6?


/tacbanon

[tacbanon]

Hi, kindly check if this should be the right pins assignment.
PortD.0 to input3 of l298
PortD.1 to input4 of l28
PortC.0 to enable of l298

by henrik: I'm surprised if that code even compiles.

Really sorry..next time I will double check before uploading.
Code:
PWM PORTD.0, 127,100
PWM PORTD.1, 127,100
PortC.0 = 1

Hope I'm close...

/tacbanon

[HenrikOlsson]

Concentrate on one bridge and motor to begin with, when you have that working apply the same procedure to the second bridge/motor.

Bridge 1 is controlled In1, In2 and ENA - in your case (according to your latest schematic) PortD.0, PortD.1 and PortC.4 respectively.
To drive the motor forward you drive PortD.0 high, PortD.1 low and apply the PWM signal to PortC.4

PortD.0 = 1
PortD.1 = 0

Main:
For i = 0 to 200              ' Ramp up.
   PWM PortC.4, i, 10
NEXT

For i = 200 to 0 Step -1  ' Ramp down.
   PWM PortC.4, i, 10
NEXT

Pause 500

Goto Main

According to the photo of the board there are a jumper for each bridge which says Remove jumper for PWM - did you do that? If you didn't the EN-pins are tied high and will short your PWM signal to the boards Vcc.

/Henrik.

[tacbanon]

Thank you Henrik for saving me hours of time just to make it ...I got it finally! I will try to add the other bridge, then post here my result.

regards,
tacbanon

[tacbanon]

Hi, I did manage to add the other motor, right now I made as a line tracker robot . Not very well on the curves yet and a little slow..hope you can look onto my codes and might able to improve the performance..

DEFINE osc 4         
ANSEL = %00000111 ' Make AN0-AN7 Analog
ANSELH= %00000000 ' Make AN8-AN13 digital

TRISA  = %00111111
ADCON1 = %00001001 
TRISC = 0
TRISD = 0
TRISB = 0

;-------------Variables
senCenter var byte
senRight  var byte
senLeft   var byte 

i var word
i = 0
PORTD.0 = 1 ' In1 
PORTD.1 = 0 ' In2
PORTB.0 = 1 ' In3 
PORTB.1 = 0 ' In4

; PORTC.4 PWM Signal  

loop1:
   Adcin 0, senCenter
   Adcin 1, senRight
   Adcin 2, senLeft
   ;Serout2 PORTD.2, 84, [$1B,$45,Dec senCenter," ", DEc senRight," ",Dec senLeft]
   ;------------------------Select options seen by the sensors
   IF senCenter > 150 and senRight > 150  then 
       Gosub movExtRight
    Endif
   
   IF senCenter > 150 and senLeft > 150  then 
       Gosub movExtLeft
    Endif
   
    IF senCenter > 150 then 
       ;Serout2 PORTD.2, 84, [$1B,$45]       
       ;Serout2 PORTD.2, 84, [$D,"     Center"]
       gosub movForward
    Endif
    IF senRight > 150 then        
       ;Serout2 PORTD.2, 84, [$1B,$45]
       ;Serout2 PORTD.2, 84, [$D,"Rigth"]
       gosub movRight
    Endif
    IF senLeft > 150 then        
       ;Serout2 PORTD.2, 84, [$1B,$45] 
       ;Serout2 PORTD.2, 84, [$D,"           Left"]
       gosub movLeft
    Endif
   ;------------------------
   
   ;gosub movForward

 
GOTO loop1               ' Do it forever

    END

movForward: '  forward
PORTD.0 = 1 ' In1 
PORTD.1 = 0 ' In2
PORTB.0 = 1 ' In3 
PORTB.1 = 0 ' In4
PWM PORTC.4 ,200,10 
PWM PORTC.5 ,200,10
return

movExtRight: ' turn more to the right
PWM PORTC.4 ,50,10 
PWM PORTC.5 ,200,10
return

movRight: '  short right
PWM PORTC.4 ,100,10 
PWM PORTC.5 ,200,10
return

movLeft: '   short left
PWM PORTC.4 ,200,10 
PWM PORTC.5 ,100,10
return

movExtLeft: ' turn more to the left
PWM PORTC.4 ,200,10 
PWM PORTC.5 ,50,10
return

senLost: ' Getback no line detected
PORTD.0 = 0 ' In1 
PORTD.1 = 1 ' In2
PORTB.0 = 0 ' In3 
PORTB.1 = 1 ' In4
PWM PORTC.4 ,200,5 
PWM PORTC.5 ,200,5
pause 50
return

Thanks in advance,
tacbanon

[HenrikOlsson]

Since you're using the 16F887 which has two CCP-modules the first thing I'd do is the rewire the thing so that the EN-pins of the L298N are connected to PortC.1 and PortC.2 and use HPWM instead.
That way the PWM generation is handled in the background, by the CCP-modules (instead of tying up the processor) and you only need to update it when you want to change the speed. Your program gets a lot of time to do other things.

Then I'd probably set up a timer interrupt to trip every 25ms or something. In the ISR I'd read the sensors and set the PWM dutycycles accordingly.