Unexpected reboot by ESP32 rush current with external circuit

SolderedElectronics / Inkplate-10-hardware

Open Source Hardware (OSH) files for e-paper display Inkplate 10.

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Unexpected reboot by ESP32 rush current with external circuit #1

Closed pasutisu closed 2 years ago

pasutisu commented 2 years ago

Environment

Inkplate 10
external circuit require 3.3V/<200mA power supply from Inkplate 10

Repro Steps

Connect external circuit and Inkplate 10.
Boot Inkplate 10.
Execute code that booting Wi-Fi logic like WiFi.status().
Sometimes reboot without any error message.

Reason I thought

ESP32 has 500mA+ rush current on booting Wi-Fi.
This board using TPS7A26 series supply only 500mA.

Solution I tried

I added a 470uF capasitor to 3.3V line near ESP32, it works well.

BornaBiro commented 2 years ago

What kind of power supply is used for the Inkplate board? Too weak power supply can cause problems, as Inkplate itself can consume 500mA while refreshing the panel and connecting to WiFi (mostly in a form of current spikes), so there is not much left for external circuits. Adding a capacitors on 3.3V rail can help with maintaining constant voltage as they can serve as a "energy storage" during current spikes.

pasutisu commented 2 years ago

I tried to supply 5V/900mA and 5V/2A to Inkplate 10 (5V/2A was more stably a bit).

I understood that if I use my circuit with Inkplate 10 stably, I need to add a LDO or caps. But I hope more powerful LDO to 3.3V line in next version!

Thanks for helping me :)