SP501E: is it a decent WLED controller?

I am looking at different boards to run WLED with my light strips, and looked at the SP501E because (in that order):

  • it looks like a finished product
  • it is compact
  • it is cheap

I have also considered the QuinLED and Wemos shield options from the hardware guide, but thought I would try the SP501E first to see if it would fit my needs.

I am a massive n00b in electronics and would need some help identifying the components on the board to make sure it has all the features that are recommended by the WLED Wiki and the Neopixel Ăśberguide.

I took the board out and it looks suspiciously simple. Could you please help me identify all of these components:

  • step down converter: this is supposed to take 24V, 12V or 5V in and out, can one component really act as a step down converter for all of these voltages to power the ESP at 3.3V? Both the QuinLED and Wemos shield have a jumper to select which step down converter to use.
  • capacitor to protect the board from the PSU: I guess there are plenty on the board
  • resistor to protect the first LED: I guess there are plenty on the board, so there should be one for that
  • logic level shifter to make sure the data wire gets 5V: I don’t recognise some of the components, maybe I am not look at it the right way
  • relay to turn the power off: I guess there are non here, and the on / off button is really just a GPIO button
  • MOSFET for the RGB pads: are these GPIOs, or are the small components next to them MOSFETs so you could actually drive 5/12/24V through these pads? They look really small to drive a few amps, but I am far from being an expert.
  • How much power should I expect to drive through a board like this? It all looks really tight especially for 12/24V and decent amperage.

Thank you all for your help! Here are the board shots, in addition to the reference ones:

Looking at this board which has similar functionality, the MOSFETs look similar and it only has one component with 6 pins when mine has 3 of them, so these may be the step down converters (the board I linked to supports 12V only).

I still don’t see a level logic shifter, maybe they cheaped out on that? Relay would be missing too which is not surprising.

I might be completely off here so if you have a clue, please share! I just want to make sure the board is safe to use and that I understand where the manufacturer cut corners.

What may I ask what is your reason for wanting to know all the components? Are you intending to modify or re-flash the ESP processor?
I have tested just about every small standalone pixel controller out there including this one and you maybe somewhat disappointed when you compare it to what Wled has to offer. The ESP 8266 is so cheap and easy to program there is no reason not to try one. With regards to learning how this board works, understanding how the ESP 8266 ticks will enable you re-program / modify other boards that use a similar processor.

The WLED wiki has details on the SP501e. https://github.com/Aircoookie/WLED/wiki/Compatible-hardware

Thank you for taking a look at this! Sorry I didn’t make it clear that I wanted to flash it to run WLED on it. My question is more around the potential limitations of that board compared to more involved custom setups, especially if I want to achieve the same fit and finish as the SP501E (so no bare electronics). I have already played with ESP32 boards, both with custom firmware and Tasmota / ESPHome, and am aiming for something that looks less intimidating for the people I am building this for.

My basic question would be: does it meet all the recommendations of the WLED hardware Wiki and the NeoPixel Ăśberguide? Does it have decent step down converters for 5V, 12V and 24V, a good capacitor to protect the board and LEDs, a resistor to protect the first LED, a level shifter to support longer LED runs, an LED for reverse polarity protection? Is there a way to know how much power could safely go through that board?

I understand it might be tricky to determine all that given all of these components are unlabeled. If we were able to get more details on this though I would be more than happy to edit the WLED Wiki so others can better understand what the SP501E is capable of.

The main limitation of the SP501 is memory. As Wled evolves 1mb boards will no longer be supported giving way to 4mb boards such as the Esp 8266 or Esp 32. As it stands the SP501 is a fairly capable board with just the need of a logic shifter if using a long data line.
With regards to power supplies I use 12v on the SP501. Not sure if there’s a 5v only variant but I’d stick to the higher voltage model as they perform better with WiFi. I don’t bother with capacitors as I only use PC converted power supplies that give clean outputs. You can use a 330 ohm resistor on the data line however I’ve never had any issues with not using one since the output signal and voltage is low on these devices. Certainly no issues using the good old WS2812b strips but make sure you only feed them 5v and not 12v as per the controller.

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Thanks @Modelman! I guess the future WLED versions would require more memory mainly for OTA updates or longer runs of LEDs? Surprising that 12V would give you better performance than 5V given both step down converters should give enough amps to the board.

Maybe I just had a problematic voltage regulator with my SP501. It just ran better with a more stable WiFi signal at 9v or 12v. Yours may be fine running at 5v.

Spec sheet for the ESP 8285 below if it’s of any help.

What’s the process for flashing these things. I have gpio0 connected to ground, powering at 3.3v through this usb to serial https://www.amazon.com/dp/B07D6LLX19 but it never reads it. Says can’t connect to the device. I have tried rx/tx swapped and straight. What am I missing? Any help would be appreciated. Thanks

They work fine. Double check your GPIO0 connection.

yeah not sure what I am missing here got gpio0 connected to ground and no matter what I get “Unexpected error: ESP Chip Auto-Detection failed: Failed to connect to Espressif device: No serial data received.”

What are you flashing with?

I finally got my sp501 and sp511’s flashed. Not sure exactly what it was just kept retrying. May have been connection issue since I was just holding a header pin to connections. I had one issue though. I was using this firmware WLED-wemos-shield/SP501E_2m.bin at master · srg74/WLED-wemos-shield · GitHub and when I try to set number of led’s to 360 it gives me error that it is too many for this chipset. But when I look at the specs for sp501e it says it supports up to 1024 leds. Mine is the 2mb version. Any ideas as to why I am getting this error? Thanks

Watch the output pin you choose to drive the LED’s.
You might be memory limited.

Start at 50 LED’s and watch the memory consumed as you add 10 LED’s at a time.
You’ll find pin’s 1,2, and 3(?) use the least added memory per LED.

Oh I thought the SP501e used a preconfigured GPIO pin. I didn’t know I could change it.

The data pin is set in the environment (GPIO 3) when it builds. There’s no reason to change it unless you plan on pulling it apart and soldering on to something else, or using the R, G, B pads to do analog.

that’s what I thought

I have a 12V, 10A power supply connected to the SP501E, can I increase the amps in the config or will I blow the unit? do I need to power the LED’s from the other end instead or will the ESP handle the Amps going through it?

You’re not at risk of “blowing the unit” by attaching a large power supply.
The SP501E will draw what power it needs to run, a few hundred milliamps typically.

What will come into play is the size of the wires that connect into and out of the controller (and the internal traces on the controller circuit board) None of those (especially the output wires) are designed to handle that kind of current and you’ll get voltage drops (likely big ones) and heating.

You’ll need to route direct power to the strip, possibly in multiple points depending on total length. This will be in parallel to the SP501E supply.


I read that the output power max is 6A so have set the max in led config to 5500mA and they seem to be working ok for now with 3x5m strips of 2811’s