Addressing multiple PORTs using one Variable

[richard]

Can all the outputs be on the same port, preferably sequential?

[flotulopex]

Can all the outputs be on the same port, preferably sequential?

As Henrik pointed, I'm somehow limited in the number of bytes I can use to address the NeoPixel strings.

Because of the very narrow timings, I cannot use routines to address the strings repeatetely with GOTOs/FOR-NEXTs/GOSUBs and so on. For this reason, I have to write code to address 24 bits for one Pixel in a row and only here, I can repeat the routine with one of the previous mentionned commands. This to say there is not only a timing issue but it is also about code length or space in the PIC.

Having this limitations in mind, I started my project addressing one string at the time and I've got plenty of time to display a minute based clock. Since all strings use the same common code and therefore the same variables, I can only differentiate them using different ports.

So if you mean to have only one NeoPixel string made of (4 digits x 7 segments x 4 Pixels [or LEDs] x 3 bytes per Pixel) + (4 Pixels x 3 bytes per Pixel) = 348 bytes, I can't address them in an array, as far as I understand it.

But what do you have in mind, please?

[Ioannis]

There is an easier protocol for addressable LEDs. The APA102 that is not strict on timing.

https://learn.sparkfun.com/tutorials...okup-guide/all

Ioannis

[richard]

Having this limitations in mind, I started my project addressing one string at the time and I've got plenty of time to display a minute based clock. Since all strings use the same common code and therefore the same variables, I can only differentiate them using different ports.

a 16f690 has 3 ports A,B and C by different ports do you mean different pins ?


Can all the outputs be on the same port, preferably sequential?
ie RC0:4 OR RC3:7 or similar

[flotulopex]

Yes, ports will be in a sequential order.

I'll be using ports:

• Seconds: PORTC.3
• Minutes Units: PORTC.4
• Minutes Thenths: PORTC.5
• Hours Units: PORTC.6
• Hours Tenths: PORTC.7

16F690 has:
PORTA.0..5
PORTB.4..7
PORTC.0..7

[richard]

By changing pinsel var you can select different portc pins
if you need the remaining portc pins then more code is needed

' PIC 16F690 @20MHz#CONFIG
    __config _FCMEN_OFF &_IESO_OFF &_CPD_OFF &_WDT_OFF &_HS_OSC &_BOR_OFF &_CP_OFF &_PWRTE_OFF &_MCLRE_OFF
#ENDCONFIG


TRISC = %00000000


DEFINE OSC 20




pinsel  var byte 
pinsel   = 128 ;  64 FOR RC:6    32 FOR RC:5 ETC 




MAIN:


    PORTC        = PORTC  | pinsel


        ASM
            nop
            nop
            nop
        ENDASM
    PORTC = 0         ' have this syntax for tests only here
        ASM
            nop
        ENDASM
        
    GOTO MAIN
END

[richard]

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