Comments on: [SOLVED] Failed to connect to ESP32: Timed out waiting for packet header

By: Bernie

Bernie — Wed, 18 Dec 2024 10:34:14 +0000

I recently had a 36 pin ESP32 WROOM 32 board that failed to boot. The 10 uF capacitor between EN and GND did not make it boot. Then I soldered a 10K resistor in parallel to the 10 uF capacitor and it started to boot.

The resistor cannot be more or less than 10K. The capacitor cannot be less than 10 uF but can be any size larger.

Another 30 pin board needed no capacitor but a 4.7K resistor between EN and GND.

By: BigT

BigT — Thu, 25 Jan 2024 23:05:32 +0000

Try using a powered USB hub for your ESP connection. It works for me without a capacitor. I suggest it may be a voltage issue. Let me know if it works for you…

By: Jaromír

Jaromír — Fri, 19 Jan 2024 10:29:29 +0000

In reply to Michael Newham. I use 47uF and works! Thank you very much. Jaromír Marusinec

By: Alexander

Alexander — Sat, 13 Jan 2024 16:14:18 +0000

Hi,
for yd-esp32-s3 board:
I tried to add capacitors and resistances, but finally I changed one of transistors (that connected to Boot) to the new one.
Old transistor is good (h21 = 238), but doen’t work.

I wish it can be usefull

By: tim

tim — Sun, 06 Aug 2023 12:15:44 +0000

In reply to DR RICHARD TURNER. ty so much i was already losing my mind

By: Ignacio Aramayo

Ignacio Aramayo — Fri, 28 Apr 2023 22:16:25 +0000

Gracias Dios indio de los ESP32 <3

By: David Albert

David Albert — Thu, 27 Apr 2023 13:42:22 +0000

@abdool there is no reason adding a small amount of bulk capacitance to the ESP32 power lines would harm the computer; certainly not due to discharge. Perhaps you are thinking of inductors which can generate high voltages when power is removed abruptly? Capacitors don’t do that. At worst, the capacitor might cause increased inrush current when the device is first powered up, but USB ports are typically well protected against overcurrent and won’t source more current than they are rated for.

Perhaps a better question is the choice of an electrolytic for this purpose. A 10uF or larger ceramic SMT capacitor (rated for 6v3 or higher) would probably be easier to mount and more importantly would have MUCH lower ESR. Electrolytics are generally not appropriate for bypassing high frequency loads.

By: abdool

abdool — Wed, 26 Apr 2023 15:24:32 +0000

why is no-one not concern about electrolytic capacitor discharge voltage. Could this not harm the computer 5v USB?

By: Sara Santos

Sara Santos — Sat, 08 Apr 2023 21:08:11 +0000

In reply to Flyover County.

Hi.
Are you using the same or different ESP32 boards?
Regards,
Sara

By: Flyover County

Flyover County — Thu, 06 Apr 2023 19:36:55 +0000

Hi,
I have a ESP32 wroom processor in a Macchina A0 OBD dongle. I have the latest Arduino IDE loaded on two laptops both are up to date. one ide installation automatically connects to the ESP32 and loads sketches, the other ide installation requires me to ground the EN pin.
any ideas in what could be the difference?