WS2818 is not working

[kokospalme]

Hello, I have a custom Board with an WS2818B chip, but FastLED does not work with it. The Board the Signal comes from, is an ESP32-board (also custom) with an opto-isolation-circuit (6N137 optocoupler). I already tried seveal configurations (WS2812, WS813, WS2811 ...) but none of them worked with the WS2818. Furthermore the datasheet of the WS2818 says, for example the low-level-time has to be 580nS - 1 uS, but the WS2813 has a low-level-time of 220nS-240nS. So the timings are sligthly different. I wondered why others got their WS2818 ICs working with FastLED and the WS2813 configuration...

Can i change the timings within the fastLED library or something? Thank you!

[zackees]

Yes, you have create your own LED controller class and pass that into the addLeds() function override.

https://github.com/FastLED/FastLED/blob/b5874b588ade1d2639925e4e9719fa7d3c9d9e94/src/chipsets.h#L577

[kokospalme]

according to this post: https://github.com/FastLED/FastLED/issues/1311 I changed the timings, but nothing is happeing... Are the variables T1, T2 and T3 correct?

template <uint8_t DATA_PIN, EOrder RGB_ORDER = RGB>
class WS2818BController : public ClocklessController<DATA_PIN, C_NS(300), C_NS(300), C_NS(600), RGB_ORDER, 4> {};
/*
 * T1       == T0H (220 … 380  nS)  —> T1 = 370
 * T2+T3    == T1L (580 … 1000 nS)  —> T2 = 600 - 300 = 300 ,   T2+T3= 300+600 = 900
 * T1+T2    == T1H (580 … 1000 nS   —> T3 = 600 ,           T1+T2 =370+600 = 900
 * T3       == T1L (580 … 1000 nS)
 *
 * RES =  > 280 uS??
 *
 */```

[zackees]

I don't know if your timings are correct, you could debug further by directly subclassing CLEDController

[kokospalme]

I don't see, where I can change the reset timing. At WS2812B it's >50uS. The WS2818B should have >280uS. Is there a chance of also changing the reset timing? Now I have tried these values (without luck):

 * T1       == T0H (220 … 380  nS)  T0H: T1    = 250
 * T2+T3    == T0L (580 … 1000 nS)  T0L: T2+T3 = 380+400 = 780
 * T1+T2    == T1H (580 … 1000 nS   T1H: T1+T2 = 250+380 = 630
 * T3       == T1L (580 … 1000 nS)  T1L: T3    = 600
 * --> RES = 1230
 *
 */```

[zackees]

what if you just do a delay() after the draw? What happens if you use the adafruit WS2812 (neopixel) library?

[smurphyUSI]

The WS2818 is an improved variation of the WS2811, so the timings should be working. Make sure they are wired correctly, because it's not the usual affair as 4-wire units.

Unfortunately, between revisions of different 'WS28XX' units, and clones, the timings are sometimes incorrectly documented. I would suggest trying again, running as WS2811 and then WS2812. Regardless of the variation, the timings should be one of those two.

[kokospalme]

I could change the timings, even the reset-timing like this, but without luck:

class WS2818BController : public ClocklessController<DATA_PIN, C_NS(250), C_NS(380), C_NS(600), RGB_ORDER, 4, false, C_NS(1230)> {};```

[smurphyUSI]

If the WS2811 and WS2812 tests don't work, then I suspect something else is wrong, such as your pinout selection for your board. You may want to tests those pins seperately with a scope or multi-meter to make sure your code is actually outputting to them.

As you said it's a custom board, I suggest moving this topic over to Reddit, but please provide the model of microcontroller you are using. There will be more people over there with experience with a specific controller. https://www.reddit.com/r/fastled

[kokospalme]

Alright, thanks for the quick answers! Maybe it's the optocpoupler's signal that's not good enough or something... I'll post if that caused the error, in case others facing the same problems

[PureTek-Innovations]

I've often used WS2818s with FastLED and have had no problems. The fault is somewhere else, try without the optocoupler

[zackees]

Following up on this, you can use this python script to calculate T1,T2,T3 from the T0H/T0L, T1H, T1L timings from the data sheet. If this fixes you then our timings are wrong.

If you get vastly different numbers than us then our timings are wrong:

// print("Enter the values of T0H, T0L, T1H, T1L, in nanoseconds: ") // T0H = int(input(" T0H: ")) // T0L = int(input(" T0L: ")) // T1H = int(input(" T1H: ")) // T1L = int(input(" T1L: ")) //
// duration = max(T0H + T0L, T1H + T1L) //
// print("The max duration of the signal is: ", duration) //
// T1 = T0H // T2 = T1H // T3 = duration - T0H - T0L //
// print("T1: ", T1) // print("T2: ", T2) // print("T3: ", T3)