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Gizmo

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Joined: 05/06/2004
Location: Australia
Posts: 5188

Posted: 02:20am 28 Jul 2026

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Ordered in a RP2040-zero to play around with, and see its got a RGB LED on the board. How would I use this LED. I've read its pin16, but switching that high or low has no effect. I'm guessing its I2C or something like that?

Glenn

PS, sorry, using the Picomite 2040 firmware.
Edited 2026-07-28 12:21 by Gizmo

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mozzie
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Joined: 15/06/2020
Location: Australia
Posts: 407

Posted: 02:39am 28 Jul 2026

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G'day Glenn,
The LED on the RP2040-Zero is a WS2812 RGB on pin 16, the inbuilt WS2812 command should do the trick

WS2812 o,gp16,1,&h0f0f0f

Makes a good status indicator if nothing else. The red and green on the units here are reversed, its GRB instead of RGB

Hope the flow bench is progressing well, looking forward to an update.

Regards, Lyle.
Edited 2026-07-28 12:50 by mozzie

EDNEDN
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Joined: 18/02/2023
Location: United States
Posts: 303

Posted: 02:42am 28 Jul 2026

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If it is a WS2812, you might try this piece of code and see if it lights up.
I wrote this code to locate the LED on an off market board so there is some extra fluff code to scan different GPIO's.

But it found my LED on GPIO-41. Yours might be the same. If not, you can start expanding the search loop by changing the "for p=41 to 41" to have a bigger range of pins. And it does use the Bitbang ws2812 o, p, 2, dd%() command suggested up above.
------------------------------------------------------------

'WS2812 color LED program
'
' The YD-RP2040 board needs the R58 solder pads bridged
' in order for the WS1280 LED to work. Otherwise it is
' disconnected.
'

Dim c%(16), dd%(1), n$(16)
c%(0) = RGB(BLACK) : n$(0) = "Black "
c%(1) = RGB(BLUE) : n$(1) = "Blue "
c%(2) = RGB(CYAN) : n$(2) = "Cyan "
c%(3) = RGB(RED) : n$(3) = "Red "
c%(4) = RGB(MAGENTA) : n$(4) = "Magenta "
c%(5) = RGB(YELLOW) : n$(5) = "Yellow "
c%(6) = RGB(WHITE) : n$(6) = "White "
c%(7) = RGB(COBALT) : n$(7) = "Cobalt "
c%(8) = RGB(MYRTLE) : n$(8) = "Myrtle "
c%(9) = RGB(MIDGREEN) : n$(9) = "Mid-Green"
c%(10) = RGB(GREEN) : n$(10) = "Green "
c%(11) = RGB(CERULEAN): n$(11) = "Cerulean "
c%(12) = RGB(RUST) : n$(12) = "Rust "
c%(13) = RGB(FUCHSIA) : n$(13) = "Fuchsia "
c%(14) = RGB(BROWN) : n$(14) = "Brown "
c%(15) = RGB(LILAC) : n$(15) = "Lilac "

print " Red Green Blue"

for p=41 to 41

print "Doing pin "; p

For i=1 To 15
dd%(0) = c%(i)
Print i;
If i<10 Then Print " ";
Print " ";n$(i);" ";

Prt_Bits(c%(i))

Bitbang ws2812 O, p, 2, dd%()
Pause 150

'Do While Inkey$=""
'Loop

dd%(0) = RGB(black)
Bitbang ws2812 o, p, 2, dd%()

Next i
next_pin:
next p

dd%(0) = RGB(black)
'Bitbang ws2812 o, GP23, 2, dd%()
Pause 1000
End

Sub Prt_Bits(arg1)

Local i, j, k%, b$

b$ = ""
k% = arg1

For i=23 To 0 Step -1
If i = 15 or i = 7 Then b$=b$+" "
j = 1 << i
If k% And j Then
b$ = b$ + "1"
Else
b$ = b$ + "0"
EndIf

Next i

Print b$
End Sub
Edited 2026-07-28 12:56 by EDNEDN

Glen0
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Joined: 12/10/2014
Location: New Zealand
Posts: 102

Posted: 03:17am 28 Jul 2026

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I use this:
Device WS2812 O, GP16, 1, RGB(BLUE)

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