Pwm portb in pic 16f628 in same time

[shahidali55]

The output of the hardware PWM module in the 16F628A is on PORTB.3. Hence this the only pin you can use for the PWM output.
Do you need exactly the same signal on 8 pins? If so, you can just take multiple connections from the same pin (PORTB.3).
If you need 8 Different PWM signals, you could use a software interrupt based routine.
You can have a look at Darrel's Multiple Software PWM.
http://www.darreltaylor.com/DT_INTS-14/SPWM.html
He has included a very nice description on how to use it.

[dragan77]

Thks.so much!
yes, I need 8 Different PWM signals!!!
I looking this site,I found code for PWM,
but when I tried COMPILE,
I have so many errors,I dont now what is happed!!
Code is:

'****************************************************************
'*  Name    : Test_SPWM.pbp                                     *
'*  Author  : Darrel Taylor                                     *
'*  Date    : 9/30/2006                                         *
'*  Version : 1.0                                               *
'*  Notes   :                                                   *
'*          :                                                   *
'****************************************************************
; Initialize your hardware first

DEFINE OSC 20
CLEAR

INCLUDE "DT_INTS-14.bas"         ; Base Interrupt System
INCLUDE "SPWM_INT.bas"              ; Software PWM module

DEFINE SPWM_FREQ  40                ; SPWM Frequency
DEFINE SPWM_RES   256               ; SPWM Resolution

DutyVars   VAR BYTE[3]              ; DutyCycle Variables
  DutyVar1 VAR DutyVars[0]          ; group them in an array for easy access
  DutyVar2 VAR DutyVars[1]          ; with FOR loops etc.
  DutyVar3 VAR DutyVars[2]

ASM
SPWM_LIST  macro                    ; Define PIN's to use for SPWM
     SPWM_PIN  PORTB, 0, _DutyVar1
     SPWM_PIN  PORTB, 1, _DutyVar2
     SPWM_PIN  PORTB, 2, _DutyVar3
  endm
  SPWM_INIT  SPWM_LIST              ; Initialize the Pins
ENDASM

ASM
INT_LIST  macro    ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler   TMR1_INT,  SPWMhandler,  ASM,  yes
    endm
    INT_CREATE                      ; Creates the interrupt processor
ENDASM

@ INT_ENABLE  TMR1_INT              ; enable Timer 1 interrupts

;_____________________________________________________________________________

RandVar   VAR WORD : RandVar = 12345
LoopCount VAR WORD

Main:                               ; Simple Demo to fade/flash some LED's
    DutyVar1 = 5                        ; Start with 3 LED's at different
    DutyVar2 = 50                       ; brightness
    DutyVar3 = 150
    pause 3000
     
    FOR LoopCount = 1 to 4              ; Reapeat 4 times
        for DutyVar1 = 0 to 150         ; Fade LED1 UP
            pause 10
            RANDOM  RandVar             
            DutyVar3 = RandVar & $3F          ; Give LED3 a random dutycycle
        next DutyVar1
         
        for DutyVar1 = 150 to 0 STEP -1 ; Fade LED1 Down
            pause 10
            RANDOM  RandVar
            DutyVar2 = RandVar & $3F         ; Give LED2 a random dutycycle
        next DutyVar1
    NEXT LoopCount     
GOTO Main

and to many errors

[dragan77]

And I tried,compile in PicBasic,this code:

define OSC 20

define SPWMFREQ  100           ' PWM frequency in Hz    

DutyCycle1   VAR  byte    ' 0-255  0=Idle Low   255=Idle High
DutyCycle2   VAR  byte 
DutyCycle3   VAR  byte    

SPWM1PIN  VAR PORTB.0          ' SPWM channel 1
define SPWM1VAR  _DutyCycle1

SPWM2PIN  VAR PORTB.1          ' SPWM channel 2
define SPWM2VAR  _DutyCycle2

SPWM3PIN  VAR PORTB.2          ' SPWM channel 3
define SPWM3VAR  _DutyCycle3
 
Include "Multi_SPWM.pbp"

DutyCycle1 = 0
DutyCycle2 = 127
DutyCycle3 = 255

Loop:
   Pause 100
Goto Loop

and I have errors:

ERROR: Variable wsave3 position request 416 beyond RAM_END 335.

Can anybody now what is problem!!!