Everytime the chips resets, we get the reason and the next boot mode.

ets Jan 8 2013,rst cause:XXX, boot mode:(YYY,ZZZ)

For XXX we can check the meaning here.

For YYY and ZZZ I am not sure but I know it has something to do with this. I think YYY stands for abc where a = MTDO, b = GPIO0 and c = GPIO.

For my ESP12E I am getting boot modes like boot mode:(1,7), thus after the reset, the code doesn't start again. It just "hangs there" forever.

I feel that it is starting the UART routine, because 1 = 001, meaning GPIO2 is at HIGH and the others are at LOW.

But maybe what I want, for it to start the setup() and loop() routines all over again is to activate the "SPI" by setting the MTDO pin to LOW and the other two to HIGH.

Can someone explain me better what are these 3 boot modes and how can I interpret the boot mode?

  • take the first number, and %4 to extract the boot mode. 99% of the time you want SPI flash, so the error code basically warns you that one of GPIO 0,2, or 15 is screwed up – dandavis Jun 18 '17 at 20:37
  • boot mode:1 - means that you are in flashing/programming mode (GPIO0 is low) - so, your sketch isn't even running - note: I've got 2 ESP-12E's and have vowed never to buy them again - all my ESP-07's and ESP-12F's are rock solid - the 12E's are basically crap that despite being "wired" exactly the same as 07's and 12F's (same circuit with just the different modules) boot erratically into random modes, and fail half way through flashing more often than not – Jaromanda X Jun 19 '17 at 1:23
  • Isn't ESP-12F the same as ESP-12E with a different board? I think I've had that GPIO0 issue in all of them. They should have used other pin than that for boot mode. In every ESP it means that only when you know you'll not upload code anymore, should you connect GPIO0 to HIGH in order to properly configure the boot mode, that's silly. Anyway the only reasons I like ESP-12E is for the USB port, the amount of exposed pins and price. – nemewsys Jun 19 '17 at 8:58
  • there's no USB on the 12E, or any ESP module for that manner... – dandavis Jun 19 '17 at 18:06

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