P1 Forth question about using Neopixel LEDs

Mike Green · 2021-08-05 19:39

Can someone point me to some explanation and examples of the use of Neopixels with Forth? I've looked at EXTEND.FTH and the included WS2812 support around line 1400, but I need some explanation of LOADMOD and RUNMOD to make sense of it. I've also found RGB and RGBS, but they don't seem to work. I'm obviously missing something. Thanks.

Maciek · 2021-08-05 19:57

I'd look for these in the tachyon5v7.spin or .list maybe ?
If anywhere, that would be my first guess .

Christof Eb. · 2021-08-06 14:39

Hi Mike,
I would not pretend, that I have understood this loadmod stuff. But I have still got Neopixels blinking. :-)

The most important word is RGBPIN ( instead of LEDPIN !).
Then you need RGBS
That's all.

Edit: There has to be some pause between RGBS commands!

Good luck, Christof

1 RGBPIN \ sets the pin 1 to be used and has to be done by the cog, that will use it

\ NeoPixel Ring on Pin 1
12 3 * bytes ledarray

: clrall
    12 3 * FOR 0 ledarray I + C! NEXT
    ledarray 12 RGBS ;

: setc ( color led -- ) \ 0 grn 1 red 2 blue
    3 * + ledarray + 1 SWAP C! \ set brightness 1 
    ledarray 12 RGBS ;

: clrled ( led -- ) \ 
    3 * ledarray + 
    DUP 0 SWAP C! 
    DUP 1+ 0 SWAP C! 
    2 + 0 SWAP C! 
    ledarray 12 RGBS ;


: spinled 
    120 FOR 
        1 I 12 MOD setc 
        100 ms
        clrall
        1 ms
    NEXT ;

ErNa · 2021-08-07 19:47

Hi Mike,
as I understand there is a little gap in the cog memory where you can load code to. Then you can run this code.

LOADMOD     ( src dst cnt -- )    C2    Load cog memory from hub memory - used internally by CODE MODULES
RUNMOD            C    Run the currently loaded code module

As RUNMOD has no parameter it just allows you to start the module you loaded before.
Update: RUNMOD passes parameters as needed to perform the function.

You find this info in google doc Search for "CODE MODULES" as examples

P1 Forth question about using Neopixel LEDs

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