ESP8266 Community Forum

- Sat Mar 03, 2018 4:26 am #74332 I'm on my 3rd ESP12-F, second computer and last patience on trying to get it to boot

When I open a 74880 baud serial monitor in Arduino IDE i get this message;

Code: Select all ets Jan  8 2013,rst cause:2, boot mode:(3,6)

load 0x40100000, len 1856, room 16
tail 0
chksum 0x63
load 0x3ffe8000, len 776, room 8
tail 0
chksum 0x02
load 0x3ffe8310, len 552, room 8
tail 0
chksum 0x79
csum 0x79

2nd boot version : 1.5
  SPI Speed      : 40MHz
  SPI Mode       : DOUT
  SPI Flash Size & Map: 32Mbit(512KB+512KB)
jump to run user1 @ 1000



This is the diagram I followed to the letter:


I've tried powering with;
2xAA batteries
5v from Arduino Uno through a D1117V33 regulator
3.3v from Arduino Uno

I've tried using 10k and 1k resistors for the pull-ups, and without the resistor on GPIO15 pull down.

The two previous ESP12F has met their fate when flashing and with what I think was an unreliable power supply, sometimes dropping under 2.8v.

This time around I decided to just hook one up, fresh from the box and try to get it to boot. That's probably where I've should've started...

Could anyone point me in a direction on where to start to try to solve this?

- Mon Mar 05, 2018 9:38 am #74373 did you ever try to flash a simple sketch?
If the module was delivered empty (w/o AT fw) I think this would be the expected behaviour.....

- Mon Mar 05, 2018 10:42 am #74375 I can give it a try. The thing is that I had 2 other identical ESP12F where I did try to flash a blink sketch but without it working. So I thought I'd try to get it running with whatever was on it when shipped.

I'll try with the AT firmware as soon as I get home, thanks for your reply! I'll post an update when I tried.

- Mon Mar 05, 2018 11:34 am #74376 Also 10K is a but marginal in my view for the GPIO15 pull down (which must be low during reset). It has to overcome the internal pull up. I would use <=4.7K to make sure it is low during boot.