Inkplate 5v2 WiFi.mode(WIFI_STA) causes reboot only right after code flash on USB power

[fiendish]

Immediately after a code flash, still plugged into USB, trying to activate the wifi radio always causes a reboot. Does not happen after manual hard reset, only after flash. Doesn't matter how long I delay activating WiFi. Device is brand new. Battery reads 4.24V.

This always causes a boot loop

void setup() {
  delay(10000);
  WiFi.mode(WIFI_STA);
}

A physical power off/on cycle stops the rebooting.

[rsoric]

Hi @fiendish ,

What happens when you try connecting with connectWiFi? Give that a try please.

The potential problem may be caused by power brownout due to a higher current demand when starting WiFi module, you said battery reads 4.24V, can you confirm that during the crash you are connected both with Battery and USB-C? Try switching to a stable 5V power supply only (no battery), try connecting to a USB port or even better a simple phone charger (as they can provide more current). Does it happen then?

Another issue which could be causing this is NVS (Non-Volatile Storage) corruption, right after you flash the WiFi RF performs a full calibration (if NVS was erased, it doesn't exist or the calibration data was broken) which in turn causes the brownout, but after a hard reset calibration data is already stored in NVS so there are no current "spikes". Assuming you are using Arduino IDE, check for "Erase all flash before sketch upload" setting in Tools -> Erase all flash... and try setting it to Disabled and see if that helps.

For more debug information try adding esp_reset_reason() to see what is causing it to reboot.

Also, I would like to add that we're working on porting the Inkplate library to updated ESP32 board definitions which may not have this issue. Could you also test esp32 dev board board definition, the latest one from espressif? Here is a tutorial on how to get the latest one. Ours is just essentially a fork of this but an older one, this may have been fixed in a newer version. This is how to connect to WiFi on that one. This insight would be helpful to us.

Try these things and let me know!

[fiendish]

Assuming you are using Arduino IDE, check for "Erase all flash before sketch upload" setting in Tools -> Erase all flash

Nope, arduino-cli. I find the IDE unpleasant to use. Pre-erasing or not makes no difference.

esp_reset_reason()

Just returns 1 every time.

The problem seems to go away with the new board definition.

[rsoric]

Hi @fiendish ,

understood, we do feel some type of way about Arduino IDE so we use a combination of VSCode and Arduino as described here.

If the problem goes away with the new board definition - that's good, we are just starting the process of porting this entire library to new board defs, a quick fix here unfortunately isn't possible. I will revisit this ticket and let you know when we have something to test. Unsure when that will be, but we're working on it and it's a priority at the moment for Inkplate.

-Rob