Results 1 to 6 of 6

Thread: Nodemcu: fuse and other questions

  1. #1
    Join Date
    Dec 2014
    Location
    Canada
    Posts
    4
    Post Thanks / Like

    Question Nodemcu: fuse and other questions

    Hello,

    I am very new to this hobby and would appreciate suggestions

    I have 50 ws2811's connected to a Nodemcu using pin D4 for the data, the ground pin on the side closest to the 'flash' button, and the VIN pin for power. I am using a 5v power adapter connected to the +- power injection wires on the WS2811 string itself. The lights will be used for window frames (inside house, not outdoors). Here is my question list:

    1) Have I wired this correctly? (When researching online, I saw a different method that didn't make sense to me)
    2) Do I need to use a fuse for this set up? If so, what do you recommend?
    3) How many WS2811 pixels can I safely use?
    4) If I enclose the Nodemcu in a plastic junction box, will the wifi signal be affected?

    Thanks for your help

    NodemcuWiring2.jpg

  2. #2
    Join Date
    Dec 2012
    Location
    Newtown CT
    Posts
    5,006
    Post Thanks / Like

    Default Re: Nodemcu: fuse and other questions

    Quote Originally Posted by onaroll View Post
    Hello,

    I am very new to this hobby and would appreciate suggestions

    I have 50 ws2811's connected to a Nodemcu using pin D4 for the data, the ground pin on the side closest to the 'flash' button, and the VIN pin for power. I am using a 5v power adapter connected to the +- power injection wires on the WS2811 string itself. The lights will be used for window frames (inside house, not outdoors). Here is my question list:

    1) Have I wired this correctly? (When researching online, I saw a different method that didn't make sense to me)
    In my opinion you have NOT wired this correctly. You should have only TWO wires going from the nodemcu to the first pixel. V- and Data. The pins you are using for those two wires are fine. In addition, the nodemcu outputs are 3.3v outputs. The WS2811 pixels are 5V inputs. If your first pixel is within 15cm of the nodemcu then you MIGHT be ok. If you are further away then I suggest putting a buffer / level shifter (aka RobG Null pixel without a pixel or similar) device to drive a proper data signal.

    You should supply power to the nodemcu using its normal (I think your model has a USB connector) pins.

    Quote Originally Posted by onaroll View Post
    2) Do I need to use a fuse for this set up? If so, what do you recommend?
    There should be a fuse in the V+ line that goes from the PSU to the WS2811 string.

    Quote Originally Posted by onaroll View Post
    3) How many WS2811 pixels can I safely use?
    A nodemcu has limited ram. It tops out between 1000 and 1500 pixels before the device starts to get unstable. How many pixels in a string is more dependent on the refresh rate you are planning to use. a 25ms refresh rate (real motion quality) has a max string length of 680 pixels. 50ms has a max string length of 1360 pixels.

    NOTE there are many discussions about why limiting the string length is a good thing. For me the critical driver that keeps my string length at or below 500 pixels is the visible delay between a color change on the first pixel of the string and the last pixel, The longer the string the more noticeable this delay becomes. There is nothing you can do to fix this. It is an artifact of the data protocol used by the WS2811 devices. HOWEVER: Some controllers can make the impact of this issue WORSE when they use a software based transmission algorithm to output the WS2811 data.

    Next issue that can severely limit the string length is your data source. If you are sending a lot of data over your WiFi network then you will get "odd" things happening on your lights. If your data is generated by an internal effects engine or from a sequence stored on a local SD card then you would not need a high quality WiFi signal.

    Quote Originally Posted by onaroll View Post
    4) If I enclose the Nodemcu in a plastic junction box, will the wifi signal be affected?
    Yes. Any enclosure will attenuate a radio signal. What you are asking is will it be to much of an attenuation? That depends on the distance to the AP and what else is between the nodemcu and the AP.


    2021 New Tune-to sign. New 40x27 matrix at the house. Retiring the Strip based matrix. Updating some of the old window frames to the new house. Adding two new songs.
    2020 Full sized show reworked for the new location. Only adding (famous last words) 13 RBLs that I finally got converted to using pixels
    2019 - Just moved into a new home (yet another change of plans). Will be dim but not dark. Too much to do at the new place to leave time for a show. Dim show (3000 pixels) had regular visits most nights.
    https://www.youtube.com/channel/UCyX...ttrsZNARkUce0Q

  3. #3
    Join Date
    Dec 2014
    Location
    Canada
    Posts
    4
    Post Thanks / Like

    Default Re: Nodemcu: fuse and other questions

    Thanks Martin
    for your help, clarifications and reply

  4. #4
    Join Date
    Dec 2014
    Location
    Canada
    Posts
    4
    Post Thanks / Like

    Question Re: Nodemcu: fuse and other questions

    Hello Again,

    Trying this again, referencing the attached image, do the red and white wires (A) coming from the light strip (I am using WS2811 nodes) connect to my 5v wall wart, and the red and white wires (B) coming from the Nodemcu connect to a usb power source?
    Thanks again for suggestions
    NodemcuWiring3.png

  5. #5
    Join Date
    Dec 2012
    Location
    Newtown CT
    Posts
    5,006
    Post Thanks / Like

    Default Re: Nodemcu: fuse and other questions

    that looks good. i would add power at the far end of the strip.


    2021 New Tune-to sign. New 40x27 matrix at the house. Retiring the Strip based matrix. Updating some of the old window frames to the new house. Adding two new songs.
    2020 Full sized show reworked for the new location. Only adding (famous last words) 13 RBLs that I finally got converted to using pixels
    2019 - Just moved into a new home (yet another change of plans). Will be dim but not dark. Too much to do at the new place to leave time for a show. Dim show (3000 pixels) had regular visits most nights.
    https://www.youtube.com/channel/UCyX...ttrsZNARkUce0Q

  6. #6
    Join Date
    Dec 2014
    Location
    Canada
    Posts
    4
    Post Thanks / Like

    Default Re: Nodemcu: fuse and other questions

    Thanks again, Martin

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •