# SB2209 (RP2040) Neopixel not turning on **URL:** \ **Category:** General Discussion\ **Created:** [May 1, 2025, 7:05pm UTC](https://klipper.discourse.group/t/sb2209-rp2040-neopixel-not-turning-on/23239 "2025-05-01T19:05:35Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![wilsgarc](https://avatars.discourse-cdn.com/v4/letter/w/f1d935/32.png) [@wilsgarc](https://klipper.discourse.group/u/wilsgarc)\ **Post date:** [May 1, 2025, 7:05pm UTC](https://klipper.discourse.group/t/sb2209-rp2040-neopixel-not-turning-on/23239/1 "2025-05-01T19:05:35Z")
New Voron 2.4 R2 build 350mm MB: Manta M8P v2 Toolhead: Stealthburner via canbus SB2209 [RP2040] head boards for stealthburner LED lights : BIGTREETECH MSB / ESB RGB Kit V1.0 Ive complete the build with no issues yet trying to setup neopixel led on stealthburner toolhead but after research I can’t get them to turn on. just don’t know what else to do Ive replace both sb2209 and RP2040 boards .. no luck I’ve replaced neopixel led strip with no luck all boards and leds are in working order tried generic cfg: stealthburner\_leds.cfg file with no luck tried simple cfg just to see if they turn on with no luck [neopixel neo] pin: RP01: gpio16 # The I/O pin connected to the neopixel. chain\_count:3 # The number of Neopixel chips that are “daisy chained” to the color\_order: GRBW # Pixel color order initial\_RED: 0.0 initial\_GREEN: 0.0 initial\_BLUE: 0.0 initial\_WHITE: 0.0 ########################## MACROS ################################# [gcode\_macro BIB] gcode: {% for flashes in range (params.COUNT|default(10)|int) %} SET\_LED LED=neo index=1 RED=0 Green=0 Blue=0 White=1 Transmit=1 SET\_LED LED=neo index=2 RED=0 Green=0 Blue=1 White=0 Transmit=1 G4 P50 SET\_LED LED=neo index=2 RED=0 Green=0 Blue=0 White=0 Transmit=1 G4 P50 SET\_LED LED=neo index=2 RED=0 Green=0 Blue=1 White=0 Transmit=1 G4 P50 SET\_LED LED=neo index=2 RED=0 Green=0 Blue=0 White=1 Transmit=1 G4 P200 SET\_LED LED=neo index=2 RED=0 Green=0 Blue=0 White=0 Transmit=1 G4 P200 SET\_LED LED=neo index=3 RED=1 Green=0 Blue=0 White=0 Transmit=1 G4 P50 SET\_LED LED=neo index=3 RED=0 Green=0 Blue=0 White=0 Transmit=1 G4 P50 SET\_LED LED=neo index=3 RED=1 Green=0 Blue=0 White=0 Transmit=1 G4 P50 SET\_LED LED=neo index=3 RED=0 Green=0 Blue=0 White=1 Transmit=1 G4 P200 SET\_LED LED=neo index=1 RED=0 Green=0 Blue=0 White=1 Transmit=1 SET\_LED LED=neo index=2 RED=0 Green=0 Blue=0 White=0 Transmit=1 SET\_LED LED=neo index=3 RED=0 Green=0 Blue=0 White=0 Transmit=1 G4 P200 {% endfor %} Ive seen other people run into this same issue with no solution some people commented that GPIO16 on SB2209 doesn’t work yet I’ve seen videos of same configuration working correctly. hoping someone can point me in the right direction ---
**Author:** ![EddyMI3D](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/eddymi3d/32/1981_2.png) [@EddyMI3D](https://klipper.discourse.group/u/EddyMI3D)\ **Post date:** [May 1, 2025, 7:14pm UTC](https://klipper.discourse.group/t/sb2209-rp2040-neopixel-not-turning-on/23239/2 "2025-05-01T19:14:50Z")
Hello @wilsgarc ! Some things are missing/can be improved: [How-To Ask for Help](https://klipper.discourse.group/t/how-to-ask-for-help/6327/1) ---
**Author:** ![wilsgarc](https://avatars.discourse-cdn.com/v4/letter/w/f1d935/32.png) [@wilsgarc](https://klipper.discourse.group/u/wilsgarc)\ **Post date:** [May 1, 2025, 7:31pm UTC](https://klipper.discourse.group/t/sb2209-rp2040-neopixel-not-turning-on/23239/3 "2025-05-01T19:31:42Z")
what do you mean missing/can be improved ? ---
**Author:** ![EddyMI3D](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/eddymi3d/32/1981_2.png) [@EddyMI3D](https://klipper.discourse.group/u/EddyMI3D)\ **Post date:** [May 1, 2025, 7:34pm UTC](https://klipper.discourse.group/t/sb2209-rp2040-neopixel-not-turning-on/23239/4 "2025-05-01T19:34:21Z")
Have you read what is mentioned in the link? In particular: [How-To Ask for Help](https://klipper.discourse.group/t/how-to-ask-for-help/6327#p-17534-provide-the-klippylog-4) and [How-To Ask for Help](https://klipper.discourse.group/t/how-to-ask-for-help/6327#p-17534-provide-the-klippylog-4) ---
**Author:** ![wilsgarc](https://avatars.discourse-cdn.com/v4/letter/w/f1d935/32.png) [@wilsgarc](https://klipper.discourse.group/u/wilsgarc)\ **Post date:** [May 1, 2025, 8:30pm UTC](https://klipper.discourse.group/t/sb2209-rp2040-neopixel-not-turning-on/23239/5 "2025-05-01T20:30:01Z")
[klippy.log](https://klipper.discourse.group/uploads/short-url/4DMo8SIqKTMOecDTTYffeQHh1sw.log) (4.1 MB) ---
**Author:** ![nefelim4ag](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/nefelim4ag/32/2387_2.png) [@nefelim4ag](https://klipper.discourse.group/u/nefelim4ag)\ **Post date:** [May 2, 2025, 12:08am UTC](https://klipper.discourse.group/t/sb2209-rp2040-neopixel-not-turning-on/23239/6 "2025-05-02T00:08:30Z")
> > > This PR updates the Neopixel (WS2812) short-pulse durations to be within the 150… ns tolerance limit specified by the WS2812 datasheet. In my testing this fixes a number of odd probabilistic behaviors tied to improperly behaving Neopixels. > > The datasheet specifically says the "0" and "1" bits should have nominal high-pulse widths of 400 ns and 800 ns respectively, but the values in the repo were 200 ns short of those values, and outside of the 150 ns tolerance permitted by the datasheet. > https://cdn-shop.adafruit.com/datasheets/WS2812B.pdf > > It isn't clear why the values used were so far outside of the datasheet nominal values, but I suspect we're inadvertently tying circuit behaviors to fixes in software that only apply to specific electrical configurations. We're probably better off exposing these as \`menuconfig\` variables if tuning is going to be needed to fix those issues for other users. There is a fresh fix commited for that. `Loaded MCU 'mcu' 126 commands (v0.12.0-464-ga3b4b39ff / gcc: (15:8-2019-q3-1+b1)` You have to update your RP2040 MCUs to the `5b2f8104c` or cherry-pick that change. Hope that helps. ---
**Author:** ![wilsgarc](https://avatars.discourse-cdn.com/v4/letter/w/f1d935/32.png) [@wilsgarc](https://klipper.discourse.group/u/wilsgarc)\ **Post date:** [May 3, 2025, 3:53am UTC](https://klipper.discourse.group/t/sb2209-rp2040-neopixel-not-turning-on/23239/7 "2025-05-03T03:53:26Z")
This solved my issue.. thanks for the help ---
**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/klipper/original/1X/64419bf2aac6639e6ef5cef200dcd456b0a01ac3.png) [@system](https://klipper.discourse.group/u/system)\ **Post date:** [June 2, 2025, 1:54pm UTC](https://klipper.discourse.group/t/sb2209-rp2040-neopixel-not-turning-on/23239/8 "2025-06-02T13:54:14Z")
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