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RPi + Other Software HD107S leds

Discussion in 'Hardware Support' started by Awawa, 4 November 2020.

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  1. Awawa

    Awawa Active Member

    Messages:
    226
    Hardware:
    RPi1/Zero, RPi3, +nodeMCU/ESP8266
    How do you communicate with sk6812? I seriously consider them but 3-wire leds are problematic using directly from Rpi. The problem is not only LED count but also refresh rate. Old solution for analog era could be not enough. Even on the lowest FPS for grabber and 60leds/meter I could be forced to abandon smoothing. I was thinking to forward data from Rpi to Arduino(USB) or ESP8266 but the serial port is bottleneck for the first and latency could be a problem for second. Or to experiment with Olimex ESP32 or Tensy?
     
  2. NeeeeB

    NeeeeB Active Member

    Messages:
    161
    Hardware:
    RPi3, +Arduino, +nodeMCU/ESP8266
    Why not use an ESP8266 (a genuine Wemos D1 mini for example, to avoid flickering) with WLed ?
    That is what I use with my WS2812b and there is no latency (and less cables as a bonus ^^)

    Previously I used an Arduino Uno and had no issue at all. (but 1 more cable ahah)
     
    Last edited: 9 November 2020
  3. Awawa

    Awawa Active Member

    Messages:
    226
    Hardware:
    RPi1/Zero, RPi3, +nodeMCU/ESP8266
    There is a latency for Wifi communication. It's insufficient for many projects and that's not what I fought for every millisecond with HyperHDR to comply with that ;) But the device I mentioned Olimex ESP32 can communicate also over ethernet and run WLED (in alpha/beta... whatever stage). Tensy >= 3.2 has highspeed serial port.

    OK, is this would work with USB->Serial communication and Adalight protocol on ESP8266 https://github.com/sticilface/Adalight-ESP8266? 2000000 baud should be enough. Only change for RGBW and rework a little for sk6812.
     
    Last edited: 9 November 2020
  4. NeeeeB

    NeeeeB Active Member

    Messages:
    161
    Hardware:
    RPi3, +Arduino, +nodeMCU/ESP8266
    If you find a way to make it work with an ESP32 too, I'd like to use that too.
    Because even if I can't see any latency with WLed, sometimes I get white flashes if my Wifi is saturated (or leds start to be out of sync and go crazy before syncing again).
    At least with Arduino it was very stable and reliable.
     
  5. Awawa

    Awawa Active Member

    Messages:
    226
    Hardware:
    RPi1/Zero, RPi3, +nodeMCU/ESP8266
    I think it's possible and will start to implement it immediately for WS2801 as SK6812 will arrive next month.

    One disturbing thing: even with highspeed serial port at 2 000 000 baud for 200 leds he've got only 100hz practically...
    And solutions with ambilight using 115 200 baud default USB serial port for Arduino? Maybe people can't notice it or they have less leds in the projects...
     
  6. NeeeeB

    NeeeeB Active Member

    Messages:
    161
    Hardware:
    RPi3, +Arduino, +nodeMCU/ESP8266
    I've got 176 leds in my setup (stil on 42" TV, need some money to upgrade to 55" ahah).
    And when I was using an arduino, speed was set to 500000 in the sketch.
    With latch time set to 0ms, I didn't see any latency at all.
     
  7. Awawa

    Awawa Active Member

    Messages:
    226
    Hardware:
    RPi1/Zero, RPi3, +nodeMCU/ESP8266
    OK, you used custom sketch. Default speed for all kind hardware Adalight adapters is 115200. And even with that sometimes there are troubles with Rpi UART configuration. Well, all is ahead of me :)

    And my current config for 55" is 98 leds :unsure:
     
  8. TPmodding

    TPmodding Administrator Staff Member Administrator

    Messages:
    1,883
    Hardware:
    RPi1/Zero, RPi2, RPi3, +Arduino, +nodeMCU/ESP8266
    it is a known bug in wled, there are some issues with the wifi part which occurs errors
     
    • Like Like x 1
  9. Awawa

    Awawa Active Member

    Messages:
    226
    Hardware:
    RPi1/Zero, RPi3, +nodeMCU/ESP8266
    Let's puts some tech stuff on WS2812b / SK6812 with connection with current Arduino sketch that is distributed along side Hyperion
    Using smoothing with continues output and down side limit removed.
    Saleae logic analyzer, just to see frames not to analyze their content.
    250 leds.

    Lets try with 15Hz:
    [​IMG]
    let's say it's OK, around 13Hz, but it's below default limit for smoothing for 2.0.0.8 and previous version.

    now 25Hz:
    [​IMG]
    not good, probably we hit the wall around 21Hz, still below minimum limit.

    now 50Hz:
    [​IMG]
    obviously we captured some out of sync moment, a little below 20Hz

    now 100Hz
    [​IMG]
    around 21Hz we met before.

    1)
    Probably increasing serial port speed would bring little benefits as these popular AT processors are just too slow to handle both high speed serial port and LED library. WLED seems to be a better solution despite problems with Wifi stability and possible little lag due to wireless communication.
    But the best solution I will probably choose is using ESP8266 as high speed controller: USB serial port could go as high as 2Mb and the CPU is 10x faster than Arduino based on popular Atmel.

    2)
    Using smoothing in that case is just delaying the output, no interpolation...
     
    Last edited: 11 November 2020
  10. Awawa

    Awawa Active Member

    Messages:
    226
    Hardware:
    RPi1/Zero, RPi3, +nodeMCU/ESP8266
    And to end that story for now: here's the hardware debug log from WLED nodemcu v2 amica:
    100hz / 250 leds / wireless / Windows 10 hosting
    [​IMG]
    As you can see it's much better, the only problem is the Wifi connection itself as can be expected.