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Planet-Laterna / Laterna-mini-V3

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Observed glitches with latest WLED bin #3

Open monoapp3 opened 1 year ago

monoapp3 commented 1 year ago 
          Thank you for this.

Will you be able to provide any detail about the output circuit? Is it straight off the esp32 or is there a level shifter? I've been trying to troubleshoot some LED glitching and find the output voltage a bit low. (Without a resistor the voltage rises a bit but the LEDs get very glitchy.)

laterna-mini-with-330ohm-resistor

Originally posted by @numindast in https://github.com/Planet-Laterna/Laterna-mini-V3/issues/1#issuecomment-1608034527

monoapp3 commented 1 year ago

@numindast could you please explain a little bit more on detail your setup.

We did not observe such a problem during our sanity tests. We are using a much older WLED version for testing. 0.12.x

Besides different software used:

Remark: all our boards have a level shifter

thanks

numindast commented 1 year ago

Thanks for your reply!

I'm going to do further tests. This might be specific to a particular type of strand I have (these from aliexpress). These use ws2812b's. I tested 3 separate bundles of 50 LEDs and found using a 220ohm resistor on the data line would drive them reliably. These are 50 LEDs per string, and the total length is 5 meters. I'm thinking I will re-test with power injection at both ends.

When I switched to a more typical LED strip with 22 ws2812b's over a 36cm length (a little over 13 inches), I'm finding reliable operation without a resistor. However I haven't put my scope on this (laterna+small strip) yet and I bet it will look different with a short strip compared to the 5m long string.

I've used both a 40w (8a/5v) Alitove supply and a little 12.5w (2.5a/5v) d-link wall wart. Incidentally I have not checked the output voltage on both, and I will check them.

I'm using WAGO connectors to make a V+ and V- bus with a 2200uF electrolytic cap between them to smooth out power flow. The strip and Laterna both draw power off those. I have a pair of small WAGO connectors for the data line to give me a test point for the scope and a place to add in the resistor. This is just a "lab bench" setup.

I'm happy to admit my scope is a cheap Owon with a cheap probe. And I'm not very good at operating scopes. However, I saw a much cleaner flat-topped square wave reaching 5v coming off a "yawl-controller" (esp8266 based mini controller) when substituted for the Laterna. I did this so I'd have something to compare against. That's when I thought I should ask :)

I love how small the Laterna Mini v3 is! So many possibilities! image

monoapp3 commented 1 year ago

interesting to see how you are powering. We usually use USB C for this, since the number of leds is not high it should be possible for you to use that setup ( if not tried yet) if you externally power the led strip as you are doing there is should be a problem.

We used similar led strip on one of our videos, if interested have a loop in our instagram @planetlaterna

Glad to hear you like the footprint!

numindast commented 1 year ago

Is powering the Mini v3 via USB-C the preferred way to power it (and the LEDs) ? Just want to clarify if back-powering the Mini the way I have is acceptable or not.

Thx :)

monoapp3 commented 1 year ago

Is powering the Mini v3 via USB-C the preferred way to power it (and the LEDs) ? Just want to clarify if back-powering the Mini the way I have is acceptable or not.

Thx :)

it is ok, no problem on that. from setup point of view, the usb c interface reduces the number of cables used. you would need similar setup as yours in case you would like to inject power..

like to see the flexibility of the board !