ESP hangs after reboot

[rith87]

I'm hitting this issue:

Code: Select all

 ets Jan  8 2013,rst cause:4, boot mode:(3,0)

wdt reset

Does this mean that boot up failed and resulted in a wdt reset? Why doesn't the ESP retry after hitting the WDT reset?

[pratik]

Maybe you should try to erase the flash and put everything in once again?
Seems like the BIN files may be corrupted. Make sure you are not writing to code sections of flash in your program.

[rith87]

Hmm.. That's unlikely since the ESP boots up fine upon a hard reset. For folks who have the same problem, I'm working around this issue by doing a hard reset from an external microcontroller.

[pratik]

So that means you have been using the system restart API?
Or is this happening if you reboot by doing a power cycle?

Startup issues can have two causes - wrong boot.bin (older version?) or maybe you compiled application for the wrong boot BIN file version!
Or you have a power supply or power-on-reset issue.

[rith87]

Or you have a power supply or power-on-reset issue.

Yup, that is my suspicion. And the long term fix would be to add some fat decoupling caps...

[gailu]

I am hitting similar issue posted in another thread http://bbs.espressif.com/viewtopic.php?f=7&t=3127. Is there any solution to hang at reset? Please note that we even tried 2000uF cap between VCC and GND with no improvement and binary is fine as external reset/power reset works when ESP is hanged.

[pratik]

NOTE: Please check this first!
GPIO15, GPIO0, GPIO2 decide the boot mode. Make sure these pins on your system are not attached to any external components! If that resolves your problem... it means that the external circuitry is causing incorrect boot mode on startup. This happens if you have unstable circuits connected to these pins.

Please note that we even tried 2000uF cap between VCC and GND

Sorry, but fat decoupling caps are no good for high speed applications! They have a huge ESR. I'd suggest a 47uF or 22uF tantalum decoupling cap + 100 nF ceramic caps close to the module/ESP8266 chip itself if you suspect decoupling issues. Also, have a good reset pin circuitry to handle power-on-reset properly as well!