ESP8266 Community Forum

Recently i was using ESP8266(ESP-01) with atmega8A to log temperature to Thingspeak.Setup was running successfully.But after a long run of 2 days,my esp8266 failed for the first time.I flashed different new version of firmware 2-3 times,but soon after 4/5 hours of run,every time the ESP8266 failed.Now it's returning garbage characters on UART randomly all by itself(without giving any command to it).

Now i thought that the ESP-01 was faulty and i ordered another ESP-12F module.The connections for the ESP-12F module is as follows

Vcc - 3.3v
GND - GND
CH_PD - pulled up(3.3v) via 10k resistor (Previously soldered in the breakout board)
GPIO0 - pulled up(3.3v) via 10k resistor
GPIO2 - pulled up(3.3v) via 10k resistor
GPIO15 - pulled down(GND) via 10k (Previously soldered in the breakout board)
RST - pulled up(3.3v) via 10k resistor
Tx - atmega8 Rx via Logic level converter(5v-3.3v/vice versa).
Rx - atmega8 Rx via Logic level converter(5v-3.3v/vice versa).

For the power supply part,i was using LM1117-3.3 with 10uF tantalum caps at both Input and Output for the 3.3v part of the circuit.Also there is a 470uF/25v electrolytic cap in between the Vcc and GND pin of the ESP.
The 5v is taken from a LM350 based adjustable Linear power supply with good quality filter caps in it.

The LM350 power supply output was set to 5v.After that, i needed the power supply for another experiment,so i switched it off,then disconnected it and thought to power the ESP-MEGA8 circuit via a 5v HTC original mobile charger.It is rated as 5v/1A output.

(Note: For the previous ESP-01 setup,i used the 5v/1A HTC charger for the 5v part and 3.3v part remained the same.)

Also i connected a 1000uF/25v electrolytic cap at the 5v output line of the HTC charger and powered the circuit from the charger.As soon i powered the circuit,the ESP was deliberately throwing Blue lights after every 5-6 seconds.So in order to know,whats happening,i connected the FTDI module between the Tx pin and GND pin of the ESP8266 and logged the data using Realterm.I will attch the logfile.It was showing something like this below in cyclic order:

ets Jan 8 2013,rst cause:4, boot mode:(3,5)

wdt reset
load 0x40100000, len 1396, room 16
tail 4
chksum 0x89
load 0x3ffe8000, len 776, room 4
tail 4
chksum 0xe8
load 0x3ffe8308, len 540, room 4
tail 8
chksum 0xc0
csum 0xc0

2nd boot version : 1.4(b1)
SPI Speed : 40MHz
SPI Mode : DIO
SPI Flash Size & Map: 8Mbit(512KB+512KB)
jump to run user1 @ 1000

rlb Ìÿ
Ai-Thinker Technology Co.,Ltd.

ready


I then switched it off and disconnected the HTC charger.This time i Pulled up the RST pin via a 10k resistor.Also i added a 470uF/25v cap between VCC & GND of the ESP module and powered it back from the LM350 based linear PSU.This time it also misbehaved and was taking random resets.I then again kill the power and restart it after some time.Then everything came back to normal and it was uploading data to the Thingspeak.com normally.

After 10-12 hrs of operation,i saw that the module was updating data to thingspeak discontinously.I then killed the power and restarted it after 5-6 hours.But this time,it is taking resets like before.My mega8 is giving commands to it as it should be.Whats the problem behind this failure???Did i bricked the module by feeding the power from the mobile charger???

Also in addition,i tried to flash a new firmware exactly described as per this page.But also after firmware upgrade,it is taking reset like previously.Also in addition,it is sometimes showing "wifi connected" without issuing any command to it.At that time,my home wi-fi network is being jammed/inaccessible.After powering off the module,the network is restoring.

Also i tried different firmware uploads.But nothing helped.Please help guys........