PL9823 RGB LEDs onl...
 
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PL9823 RGB LEDs only glow white.

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(@borfavor)
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Joined: 1 year ago
Posts: 3
Topic starter  

I have setup 16 PL9823 LEDs in series connected to a Arduino Pro Micro clone and powered by an external power supply. All according to the GitHub wiki here:
https://github.com/SHWotever/SimHub/wiki/Arduino--Setup#powering-considerations

This is the current behaviour when I try to use the leds:

  1. I plug in the power cord. The LEDs turn on, bright blue. All of them, no flickering.

  2. I plugin the USB cable to the Arduino without flashed firmware and the LEDs stay in the same state.

  3. I flash the sketch to the Arduino and all the LEDs go the a full brightness white. Even though the activity LEDs on the Arduino flash in accordance to the input that it gets (like a static blinking effect), the actual RGB LEDs don't change at all.

Because it can do full white I feel like the LEDs are fine. It also only does full white when there is a firmware with the correct PIN assigned, so I feel like it's a software issue. I've tried connecting to different pins (PWM/Digital only) and I feel like I'm out troubleshooting options

Is de Arduino Pro Micro clone a problem? When compiling and uploading, that's the board I select.

This is the board I bought:
https://www.aliexpress.com/item/32768308647.html?spm=a2g0o.order_list.order_list_main.45.ca1d79d2U8PXM1&gatewayAdapt=glo2nld

Any help would be greatly appreciated


   
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(@admin5435)
Prominent Member Admin
Joined: 7 years ago
Posts: 736
 

Hi ! I don't think the board is the culprit, smart leds should not light blue "by themselves" when freshly powered, they stay off. I would think about a wiring issue (make sure to refer to the exact model dashsheet about pin order, it might vary).

One other common cause is wiring them in reverse plugging the arduino to "dout" (or dio depends of the datasheet semantic)  instead of "din", such mistake often leads to white leds. 

A last possibility, it's not true PL9823, lot of aliexpress product pages or similar websites just cumulates many chip names (ie WS2812 APA102, PL9823,  YF923) and it's really misleading. Each chip have different requirements about driving frequency etc ... I've even seen some basic rgb leds being associated with "PL9823" mention sometimes, which is completely false 🙁 they look similar with 4 leads). 


   
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(@borfavor)
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Joined: 1 year ago
Posts: 3
Topic starter  

@admin5435 Thanks for the reply! Some things to try out and double check. I have two questions:

1. What are you refering to when you say "make sure to refer to the exact model dashsheet about pin order". The pins on the LED's?

2. I did order them from aliexpress with some crudely translated datasheet, so being scammed for a few bucks might be an option. Would these NeoPixel 5mm LEDs be compatible? I'm pretty new to this, but Neopixel sounds like a reliable name and the pin order is compatible with my plans/PCB.


   
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(@borfavor)
Active Member
Joined: 1 year ago
Posts: 3
Topic starter  

They work now! For any Googlers coming in: I declared them as WS2812B LEDs in the setup tool!


   
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(@spartacus84)
New Member
Joined: 1 year ago
Posts: 1
 

I second this.  I was getting so frustrated, read this and yes, use the WS2812B LED option....  weird..


   
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(@trentrand)
New Member
Joined: 11 months ago
Posts: 1
 

I was another case of needing to use WS2812B LED option instead of PL9823. I ordered my LEDs from Aliexpress and they're listed as the PL9823 F5.

Use option 'RGB Encoding' if the colors aren't as you expect.


   
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