Bit Angle Modulation (BAM) in a PIC

**Darrel Taylor** · - 8th November 2009, 20:59

Originally Posted by talatsahim

will work mibam with hserin on 16F828?

Yes it will.

**talatsahim** · - 8th November 2009, 23:34

Originally Posted by Darrel Taylor

Yes it will.

Sorry, my very poor english.
Im new pbp user.
can you help me why not work my code?
Device 16F628

Code:

DEFINE OSC 20
CLEAR

;_________________________Interrupt Context save locations]_________________

wsave       var byte    $20     SYSTEM      ' location for W if in bank0
wsave1      VAR BYTE    $A0     SYSTEM      ' location for W if in bank1
wsave2      VAR BYTE    $120    SYSTEM      ' location for W if in bank2
ssave       VAR BYTE    BANK0   SYSTEM      ' location for STATUS register
psave       VAR BYTE    BANK0   SYSTEM      ' location for PCLATH register
;----[ MIBAM Setup ]--------------------------------------------------------
BAM_COUNT CON 3                     ; How many BAM Pins are used?
INCLUDE "MIBAM.pbp"                 ; Mirror Image BAM module

BAM_FREQ    CON 100
DEFINE BAM_INFO 1  
DEFINE HSER_BAUD 250000
DEFINE HSER_CLROERR 1
DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 20h 



KANAL       CON 3   
BREAKTIME   VAR BYTE
DMXFLAG     VAR BIT
STARTBYTE   VAR BYTE
ADR         VAR BYTE
RVAL        VAR BYTE
GVAL        VAR BYTE
BVAL        VAR BYTE
YVAL        VAR BYTE
X           VAR BYTE
DUMMY       VAR BYTE
i           VAR BYTE

'*****************  MIBAM  ***************************************************
RED         VAR BYTE
GREEN       VAR BYTE
BLUE        VAR BYTE

ASM
BAM_LIST  macro                     ; Define PIN's to use for BAM
     BAM_PIN (PORTB,5, RED)         ;   and the associated Duty variables
     BAM_PIN (PORTB,6, GREEN)
     BAM_PIN (PORTB,7, BLUE)
  endm
  BAM_INIT  BAM_LIST                ; Initialize the Pins
ENDASM
'*****************************************************************************
TRISA=%00111001
TRISB=%00000010 

ScopeSync   VAR     PORTB.2   
RXT         VAR     PORTB.1
ERR         VAR     PORTB.4

CMCON=7        
VRCON=0 
OPTION_REG.7 =0
INTCON =%11000000  



START:
PAUSE 100
DUMMY=0
ADR = KANAL-1
RED=50
GREEN=100
BLUE=180
ERR=0
GOTO LOOP
'--------->>>>>>>>

DMXBAK:
i=i+1
IF i> 200 THEN RETURN
BREAKTIME =1:DMXFLAG = 0
pulsin  RXT,0,BREAKTIME 

if BREAKTIME = 0 then return  
if BREAKTIME < 30 then DMXBAK 

PIE1.5=1 
RCREG = dummy 
RCREG = dummy '
SPBRG = 0 
TXSTA.2 = 0 
TXSTA.4 = 0 
RCSTA.7 = 1 
RCSTA.6 = 0  
RCSTA.4 = 0 
RCSTA.4 = 1 

while RCIF = 0:wend 
STARTBYTE = RCREG
if STARTBYTE = 0 then 
     
    for x = 1 to ADR
    while RCIF = 0:WEND 
    dummy = RCREG 
    next x
    
    DATAAL:
    RVAL= RCREG 
    RCREG = 0 
    RCREG = 0 
    GVAL= RCREG 
    RCREG = 0 
    RCREG = 0 
    BVAL= RCREG 
ENDIF
RCSTA.7 = 0 
DMXFLAG=1
return


LOOP:
    IF DMXFLAG=1 THEN
        RED= RVAL
        GREEN=GVAL
        BLUE=BVAL
    ENDIF
GOSUB DMXBAK
    IF i>200 THEN 
        ERR=0
        ELSE
        ERR=1
    ENDIF
i=0
DUMMY=0

GOTO LOOP

END

**Darrel Taylor** · - 9th November 2009, 00:28

Originally Posted by talatsahim

can you help me why not work my code?

Yes I can ...

HSER defines only work with HSERIN/HSEROUT. If you are reading RCREG manually, the baud rate will not have been set by PBP and you will have to do that manually as well.
pulsin RXT,0,BREAKTIME, PULSIN does not work with interrupts. The timing will be wrong and you'll almost never see a Break pulse that way. Fortunately, the USART does it for you. Look for an FERR flag (framing error) which happens on every Break.
INTCON =%11000000, interrupts are controlled by the MIBAM routines. Don't change any interrupt registers.
PIE1.5=1, you've enabled the USART receive Interrupt ... don't do that.
RCREG = dummy, RCREG is a Read-Only register. Don't know what you were trying to do there.
SPBRG = 0, it's unlikely that you would want to put SPBRG (Baud Rate Generator Register) to 0 for any reason.
TXSTA.2 = 0, It's unlikely that you would want to put the USART in Low Speed mode when running at 250Kbaud.
TXSTA.4 = 0, OK, it's not synchronous mode .... but what is it?
I have no idea what you are trying to do here. RCREG is read-only, and you're reading 3-bytes from a maximum 2-byte buffer, without checking to see if anything is there.
Code:
```
DATAAL:
RVAL= RCREG 
RCREG = 0 
RCREG = 0 
GVAL= RCREG 
RCREG = 0 
RCREG = 0 
BVAL= RCREG 
ENDIF
RCSTA.7 = 0 
DMXFLAG=1
return
```

Back to the Drawing Board.

**talatsahim** · - 9th November 2009, 01:48

"RCREG=DUMMY" was copy-paste from a sample code
how can I set receive port with correct commands?
and how sense break signal with FERR ?

[QUOTE=Darrel Taylor;80570]Yes I can ...

DEFINE OSC 20
CLEAR
;_________________________Interrupt Context save locations]_________________

wsave var byte $20 SYSTEM ' location for W if in bank0
wsave1 VAR BYTE $A0 SYSTEM ' location for W if in bank1
wsave2 VAR BYTE $120 SYSTEM ' location for W if in bank2
ssave VAR BYTE BANK0 SYSTEM ' location for STATUS register
psave VAR BYTE BANK0 SYSTEM ' location for PCLATH register
;----[ MIBAM Setup ]--------------------------------------------------------
BAM_COUNT CON 3 ; How many BAM Pins are used?
INCLUDE "MIBAM.pbp" ; Mirror Image BAM module

BAM_FREQ CON 100
DEFINE BAM_INFO 1
' MUST BE HERE DEFINE USART PARAMETER?

KANAL CON 3 'my dmx adress, 3.byte red, 4. byte green, 5. byte blue
BREAKTIME VAR BYTE
DMXFLAG VAR BIT
STARTBYTE VAR BYTE
ADR VAR BYTE
RVAL VAR BYTE
GVAL VAR BYTE
BVAL VAR BYTE
YVAL VAR BYTE
X VAR BYTE
DUMMY VAR BYTE
i VAR BYTE

'***************** MIBAM ************************************************** *
RED VAR BYTE
GREEN VAR BYTE
BLUE VAR BYTE

ASM
BAM_LIST macro ; Define PIN's to use for BAM
BAM_PIN (PORTB,5, RED) ; and the associated Duty variables
BAM_PIN (PORTB,6, GREEN)
BAM_PIN (PORTB,7, BLUE)
endm
BAM_INIT BAM_LIST ; Initialize the Pins
ENDASM
'************************************************* ****************************
TRISA=%00111001
TRISB=%00000010

ScopeSync VAR PORTB.2
RXT VAR PORTB.1
ERR VAR PORTB.4

CMCON=7
VRCON=0
OPTION_REG.7 =0

START:
PAUSE 100
DUMMY=0
ADR = KANAL-1
RED=50
GREEN=100
BLUE=180
ERR=0
GOTO LOOP
'--------->>>>>>>>

DMXBAK:
i=i+1
IF i> 200 THEN RETURN
BREAKTIME =1MXFLAG = 0
pulsin RXT,0,BREAKTIME ' I DONT KNOW HOW USE FERR THIS POINT

if BREAKTIME = 0 then return
if BREAKTIME < 30 then DMXBAK

BRGH=1 ' 250000 BAUD ?
SPBRG = 4 ' 250000 BAUD ?
'AND HOW CAN I "DEFINE HSER_CLROERR 1" WITHOUT DEFINE?

RCSTA.7 = 1
RCSTA.6 = 0
RCSTA.4 = 0
RCSTA.4 = 1

while RCIF = 0:wend
STARTBYTE = RCREG
if STARTBYTE = 0 then

for x = 1 to ADR 'MY ADRESS 3, SKIP 2 BYTE
while RCIF = 0:WEND
dummy = RCREG
next x

DATAAL:
RVAL= RCREG ' 3.BYTE, START OF MY DATA STREAM, RED VALUE
GVAL= RCREG '4 BYTE.. GREEN VALUE
BVAL= RCREG '5. BYTA BLUE VALUE
ENDIF
RCSTA.7 = 0
DMXFLAG=1
return

LOOP:
IF DMXFLAG=1 THEN
RED= RVAL
GREEN=GVAL
BLUE=BVAL
ENDIF
GOSUB DMXBAK
IF i>200 THEN
ERR=0
ELSE
ERR=1
ENDIF
i=0
GOTO LOOP

END

**Darrel Taylor** · - 9th November 2009, 02:27

Sorry talatsahim,

This little bit of code I made, has already turned into several commercial products.
I have no problem with that, and everyone is free to do so if they wish.

But, some things you just have to do on your own.
If you can come up with the rest, that's great.

Best regards,

**talatsahim** · - 9th November 2009, 03:37

thanks all

Originally Posted by Darrel Taylor

Sorry talatsahim,

This little bit of code I made, has already turned into several commercial products.
I have no problem with that, and everyone is free to do so if they wish.

But, some things you just have to do on your own.
If you can come up with the rest, that's great.

Best regards,

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thanks

thanks again

is 250000 baudrate code secret????

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