Unstable/load testing

Issues
1

So I am experimenting with long cable - just because mainly so please bare with me.

I have a 240v/10a psu, which I am essentially ‘load testing’ with a 4x 32x8 matrix.

The psu was not a particularly expensive one… but having stability issues and I’d like to diagnose it.

The esp is in a box with the psu, and they are connected via a cable to this matrix of LEDs.

Initially all works well.

It cycles through a few modes on loop, including full white.

It crashes OFTEN. USUALLY (maybe even always) on full white.

Voltage drop is a strong candidate… however the esp is connected directly to the PSU… It is the lights that are a long way away…

How can I diagnose this?

Can LEDs on a long wire cause instability?

I’ve gradually retreated from a limit of 9500, to 7500 to 6000 and eventually it still crashes.

I had wondered if it was temperature - empirically I had observed this as the enclosure (sealed) not it 30 degrees c.

Please help me understand the imitations I am hitting here…

Maybe it is the transitions??

This is what the internals look like

PXL_20241007_190830061
PXL_20241007_1908300611920×1442 309 KB

2

Couple of questions:

What is the Output voltage of your power supply?
Your long cables are not carrying 10A’s of current at 240V (I sincerely hope not).
It makes a huge difference if your cables drop 1.3V and your intended voltage is 5V or 12V.

Have you tried an independent power supply for the ESP?
Crashes are often caused by brown-outs and/or noise on the supply line.
Add a 2nd 5V 2A supply used only to provide power to the ESP.
You’ll want to make sure you have a ground connection from the 2nd supply to the 1st or alternatively, run a small dedicated data and ground line directly from the ESP to the matrix.

Try moving the ESP much closer to the matrix.
You could try this in conjunction with # 2) to see if there’s any data corruption happening on your long line.

Try a heftier power supply, connect only 1/2 or 1/4 of the matrix.
You could try and configure WLED for only 1/2 or 1/4 of the matrix.

3

It sounds like you’re facing multiple potential issues with your setup. Here are some steps to help diagnose the problems:

  1. Voltage Drop: Long cables can indeed cause voltage drop, especially under high load. Measure the voltage at the LED matrix using a multimeter to see if it’s significantly lower than what you’re supplying at the PSU.

  2. Power Distribution: Make sure your power is distributed evenly along the matrix. Consider adding capacitors close to the LED strips to help stabilize the voltage.

  3. ESP Power Supply: Ensure the ESP is getting a stable power supply. If it’s connected directly to the PSU but far from the LEDs, there might be noise introduced. Try powering it separately with a reliable 5V source.

  4. Thermal Issues: Given the sealed enclosure, monitor the temperature inside. If it’s reaching high levels, that could lead to instability. Consider adding ventilation or using a heatsink.

  5. Signal Integrity: Long distances can also affect the data signal integrity. Make sure you’re using a quality data cable and consider adding a level shifter or using a shorter, shielded cable for the data line.

  6. Transition Effects: If the crashes occur during high-load transitions (like full white), it could indicate an overload condition. Gradually test with fewer LEDs to see if the issue persists.

  7. Monitoring: Use logging or a simple debug output on the ESP to capture any errors or warnings before it crashes, which might provide clues.

By systematically testing each aspect, you should be able to pinpoint the cause of the instability. Let me know how it goes or if you have specific tests in mind!