Addressing multiple PORTs using one Variable

[Ioannis]

have you tried to light a rgb led strip with a 690 @20mHz yet ?
i have doubts that such a slow chip will do the deed

That's why I proposed APA102 chips. Not strict on the clock frequency.

Ioannis

[flotulopex]

have you tried to light a rgb led strip with a 690 @20mHz yet ?

Check this:

[flotulopex]

And here's the project's code for now.

[Ioannis]

Have not checked al of your code, but in the ***_B routine you include many time the same code. Why not insert it one time and then use GoSub to it? Better efficiency and memory usage.

Also I see you insist on using this difficult protocol. Consider the APA101 as it is less strict and can be used on slow MCUs

Ioannis

[flotulopex]

I tried to not repeat the code and use GOTOs or GOSUBS but then, if I do so, the NeoPixel string won't work anymore.

Would the use of an alternative LED string as you mention sove the problem of the ports/code/timing?

I can change for another system but would you have a code snippet to help me started with APA102 please? I've never heard about this one before.h

[Ioannis]

Here is a copy of the Richards example.

'***************************************************************************
'*  Name    : ap102.pbp                                                    *
'*  Author  : richard                                                      *
'*  Notice  :                                                              *
'*          :                                                              *
'*  Date    : 10/11/2017                                                   *
'*  Version : 1.0                                                          *
'*  Notes   :  only tested on pic18 @64 MHZ                                *
'*          : pic18f26k22
'***************************************************************************

#CONFIG
  CONFIG  FOSC = INTIO67
  CONFIG  PLLCFG = ON
  CONFIG  PRICLKEN = OFF
  CONFIG  FCMEN = OFF
  CONFIG  IESO = OFF
  CONFIG  PWRTEN = OFF
  CONFIG  BOREN = SBORDIS
  CONFIG  BORV = 190
  CONFIG  WDTEN = ON
  CONFIG  WDTPS = 32768
  CONFIG  CCP2MX = PORTC1
  CONFIG  PBADEN = OFF
  CONFIG  CCP3MX = PORTB5
  CONFIG  HFOFST = ON
  CONFIG  T3CMX = PORTC0
  CONFIG  P2BMX = PORTB5
  CONFIG  MCLRE = EXTMCLR
  CONFIG  STVREN = ON
  CONFIG  LVP = OFF
  CONFIG  XINST = OFF
  CONFIG  DEBUG = OFF
  CONFIG  CP0 = OFF
  CONFIG  CP1 = OFF
  CONFIG  CP2 = OFF
  CONFIG  CP3 = OFF
  CONFIG  CPB = OFF
  CONFIG  CPD = OFF
  CONFIG  WRT0 = OFF
  CONFIG  WRT1 = OFF
  CONFIG  WRT2 = OFF
  CONFIG  WRT3 = OFF
  CONFIG  WRTC = OFF
  CONFIG  WRTB = OFF
  CONFIG  WRTD = OFF
  CONFIG  EBTR0 = OFF
  CONFIG  EBTR1 = OFF
  CONFIG  EBTR2 = OFF
  CONFIG  EBTR3 = OFF
  CONFIG  EBTRB = OFF
#ENDCONFIG

 led_num  con 3  
 pixels  var byte[led_num * 3]
 pallet   var byte[21]
 apa_global VAR byte bank0       ;global level 0-31
 bit_cnt    VAR byte bank0 
 i VAR byte
 k VAR byte
 j VAR byte
goto overpix
asm 
_showpix 
       movlw    LOW _pixels 
       movwf     FSR2L
       movlw   high _pixels
       movwf   FSR2H 
       movlw 4 
       movwf  _bit_cnt
       movlw 0 
s_frame              ;start frame  4x 00 bytes
       bcf    PIR1,SSPIF
       movwf  SSPBUF
stspi  BTFSs    PIR1,SSPIF       
       bra stspi 
       decf   _bit_cnt
       bnz   s_frame
       movlw _led_num 
       movwf  _bit_cnt
n_led       
       movlw 0xe0
       iorwf _apa_global,W
       bcf    PIR1,SSPIF
       movwf  SSPBUF   ;global led frame
glspi  BTFSs    PIR1,SSPIF       
       bra glspi        
       movf    POSTINC2 ,W   ;blue
       bcf    PIR1,SSPIF
       movwf  SSPBUF
blspi  BTFSs    PIR1,SSPIF       
       bra blspi       
       movf    POSTINC2 ,W   ;green
       bcf    PIR1,SSPIF
       movwf  SSPBUF
gnspi  BTFSs    PIR1,SSPIF       
       bra gnspi
       movf    POSTINC2 ,W    ;red
       bcf    PIR1,SSPIF
       movwf  SSPBUF
rdspi  BTFSs    PIR1,SSPIF       
       bra rdspi
       decf   _bit_cnt
       bnz   n_led 
       movlw   _led_num /8 +1  ;find magic number  of bytes for stop frame
       movwf  _bit_cnt
       movlw 0  
stop_frame                 ;send stop frame
       bcf    PIR1,SSPIF
       movwf  SSPBUF
stopspi  BTFSs    PIR1,SSPIF       
       bra stopspi 
       decf   _bit_cnt       
       bnz   stop_frame
       return 
endasm        
overpix: 
  
    define OSC 64
    OSCCON = %11110000            
    ANSELb = 0
    ANSELA = 0
    ANSELC = 0
    SSPCON1=$20;
    SSPSTAT=$40;
    trisc=%11010111
    apa_global=1  
    latb.0=1  
    trisb=%11111110
    arraywrite pallet,[255,0,0 ,0,255,0 ,0,0,255, 255,255,0 ,255,0,255 ,0,255,255, 255,255,255]
    k=0      ;colour index
    j=0
    gosub shuffle 
    
aloop: 
    call  showpix
    gosub shuffle
    pause  40
goto aloop

And a YouTube video here



Ioannis

[richard]

the youtube link is a dud, but i take it that it works even though the timing is a little out of specs