Cannot recover from Fatal exception (0): problem during boot

[aditgupta100]

epc1=0x402147a4

This is the address of the instructions that cause exceptions. Does anyone here have the .S file of the output binary that has been causing exceptions? That file is absolutely necessary to get an idea of which function is actually triggering exception.
Random resets are power supply issue most of the time. But seems like something else here, I am not able to reproduce this issue.
Feel free to send me the binary files + your ESP8266 system config info on pratik@espressif.com so that I can check the binaries out. A .S file is much appreciated!

By the way, if you are breadboarding with ESP8266, do watch out for ground loops. A ground loop on a breadboard will mess your system if there are RF components involved.

Sent you the mail with the binaries that i've tried. Ensured no ground loops are there.
nodemcu_integer_0.9.x : 0X00000
esp_init_data_default.bin : 0XFC000

[pezGordo]

thanks for the answers

today I tried esp download tool and get the efuse error

so I changed module and new one works, great !

once flashed with esp upload tool, I see boot message

but typing I receive back garbage chars

so I get leaded to and try

http://www.esp8266.com/viewtopic.php?p=34267#p34267

after that I can do serial at 115200 and perform AT commands

please note that for the first module, which when I try to upload flash with esp flash download tool is throwing efuse error, I just used Arduino IDE 1.8 to upload my sketch, and the fatalexception(0) began. I didn't test it before.

now I ask, is it safe to upload sketches with Arduino 1.8 ? or efuse ain't related to this ?

thanks again

EDIT: yes is safe to upload sketches with Arduino 1.8 !! I did and its working ... thanks

[WheresWally]

Has anyone found a way to recover from this bootloop issue?
I have 2 12E modules with this affliction.
I was hoping for settings for flashing that would over come this.
Or at least the reason why the EFUSE error means "buy another" module.

I have proper power supply, I realise that the 3,3V on an Arduino board is not enough to feed the ESP8266 with 300mA it needs.

[pratik]

If somehow your program or flashing software is messing with the eFuse in the ESP8266, you will brick your module and it is not recoverable. The purpose of eFuse is to be programmed only once. And when you set your module to OTP or enable protection using eFuse by mistake, you brick your module.
There is no documentation on the eFuse part right now for certain internal reasons.