ESP32 LED control, power issues

[eva_402]

Hey guys, I’m new here and need some help… I’m building a smart LED controller with ESP32, the firmware is mostly done (like 80% lol), it can control 16 LEDs over WiFi and accept commands from my phone app, but now I have a problem. When I turn on more than 10 LEDs at same time, sometimes ESP32 just resets randomly… I tried adding extra capacitors but still happen, not sure if it’s power issue or coding?

Also, my prototype is on breadboard and looks messy, I want to make a proper PCB now, but I’m little confused… how to route the traces for 5V LED power separate from ESP32 logic, and also where to place the decoupling caps… I never done PCB for this kind project before, any tips will really help!

 

[bidrohini]

It sounds like your ESP32 resets are probably due to current draw. Even with extra capacitors ..... can’t reliably supply multiple LEDs at once .... wires and contacts have too much resistance. You shouldpower the LEDs from a separate 5 V supply ... capable of handling all LEDs ..... keeping the ESP32 logic supply isolated. Make sure to join the grounds. REad this on flickering LED due to power isses: https://esp32.com/viewtopic.php?t=45075

On PCB routing: keep LED power traces thick (1 mm+) .... and route them separately from the ESP32 logic traces. Place 0.1 µF decoupling caps close to all ESP32 VCC pins, plus maybe a larger 10–100 µF cap near the main 5 V input for LED load. Also, avoid routing LED traces under the ESP32 to minimize noise, and keep data/signal lines short.

For a first PCB: make LED power and logic power clearly separate, use ground planes for the ESP32 side, read this guide to understand power and ground planes: https://www.pcbway.com/blog/PCB_Des...gn_Considerations_in_PCB_Layout_862aaa8c.html and double-check your current capacity for the LED traces. That should reduce resets and make your board more reliable.

 

[eva_402]

It sounds like your ESP32 resets are probably due to current draw. Even with extra capacitors ..... can’t reliably supply multiple LEDs at once .... wires and contacts have too much resistance. You shouldpower the LEDs from a separate 5 V supply ... capable of handling all LEDs ..... keeping the ESP32 logic supply isolated. Make sure to join the grounds. REad this on flickering LED due to power isses: https://esp32.com/viewtopic.php?t=45075

On PCB routing: keep LED power traces thick (1 mm+) .... and route them separately from the ESP32 logic traces. Place 0.1 µF decoupling caps close to all ESP32 VCC pins, plus maybe a larger 10–100 µF cap near the main 5 V input for LED load. Also, avoid routing LED traces under the ESP32 to minimize noise, and keep data/signal lines short.

For a first PCB: make LED power and logic power clearly separate, use ground planes for the ESP32 side, read this guide to understand power and ground planes: https://www.pcbway.com/blog/PCB_Des...gn_Considerations_in_PCB_Layout_862aaa8c.html and double-check your current capacity for the LED traces. That should reduce resets and make your board more reliable.

That makes sense, so it’s probably a power issue rather than my code. I’ll try using a separate 5 V supply for the LEDs and make sure to keep the ESP32 logic isolated. Thanks for pcb tips, jst want to confirm 1 thing, in your view, the led traces should be thicker than the logic traces ?

 

[bidrohini]

Yeah, definitely .... LED power traces should be much thicker than logic traces because they carry more current. For a few hundred mA per LED, 1 mm or wider is usually safe, while ESP32 logic/data traces can stay 0.2–0.3 mm.

Another tip: try to keep LED traces short and direct, and avoid running them under the ESP32 to reduce noise

These are not necessary precautions but these things help ....

 

[danadak]

Might be useful PCB design rule guides -

PCB Trace and Space Handbook | Sierra Circuits

Sierra Circuits’ Trace and Space Handbook provides guidelines for designing traces with consistent impedance and reduced EMI.

www.protoexpress.com

 

[jonas123]

If your ESP32 LED control is facing power issues, the most common cause is insufficient or unstable current supply. Avoid powering LEDs directly from the ESP32 GPIO pins, as they can only supply limited current. Instead, use an external power source with a proper driver like a transistor or MOSFET. Also, make sure to share a common ground between the ESP32 and the power supply. Adding a capacitor across the supply can help stabilize voltage and prevent flickering or resets.

 

[danadak]

What are your led specs, current and voltage needed ?