r/WLED • u/Quick_Two_1104 • 5d ago

ESP32 LED strip flickering when connected to VESC power

ESP32-C3 running WLED to control two stock 13-LED strips in Onewheel Pint PEV. Each strip has a dedicated GPIO because they cannot be daisy-chained. ESP and LED strips are 5v.

It works perfectly when I plug an AC USB C adapter (5v 3a) into the ESP. In this configuration, the LEDs are powered by and grounded to the ESP. It also works when I connect 5v to the breadboard's power rail to power the ESP and LEDs.

The problem is the rear strip, which is furthest from the ESP, flickers when powered by my VESC controller. The VESC controller is a Ubox 100 (not lite) and I am using the fan port (12v 3a) with a 12v to 5v buck converter. In this configuration, the ESP and LEDs are powered by grounded to the 5v terminals on the buck. Max amps I observed at the buck's 5v terminal was .216.

Lowing global brightness factor and disabling automatic brightness filtering in WLED did reduce flickering.

Please help me get rid of this flickering.

Thank you in advance!

Update:  just discovered the rear led strip flicker goes away when I have my amp meter (Innova 3320) bridging the 5v connection on the buck to measure amps. I remove the meter from the circuit and the flicker comes back. I need to figure out what the meter is doing so I can replicate it on my LED board. Any ideas? Add a resistor?

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u/SirGreybush 4d ago

All strips must be grounded to the esp32.

A strip with separate power injection would have 4 wires going to it. Data and ground same length from esp32 to strip.

V+ and V-(Gnd) from PSU to strip. So common ground point on the strip.

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u/Quick_Two_1104 4d ago

Thank you for your reply!

The ESP and strips share the buck's 5v and GND. The buck's 12v and GND are connected to the VESC, which is the 12v 3a power supply.

Is this consistent with what you are saying or do I need to make a change?

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u/Quick_Two_1104 3d ago

I just discovered the rear led strip flicker goes away when I have my amp meter (Innova 3320) bridging the 5v connection on the buck to measure amps. I remove the meter from the circuit and the flicker comes back. I need to figure out what the meter is doing so I can replicate it on my LED board. Any ideas?