How to get the ESP8266 to work in update mode? - arduino

Question

I have been trying to get my WiFi module, ESP8266 to work in the "update mode" where you connect GPIO_0 to ground.
The board is functional when GPIO_0 is disconnected from ground and I am able to use AT commands to talk to it via the Arduino serial monitor.
Following is what it prints upon connecting:
ets Jan 8 2013,rst cause:4, boot mode:(3,6)
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
rrlÌÿ
Ai-Thinker Technology Co.,Ltd.
ready
However, I cannot do most things as the firmware is out of date.
As a result, I am trying to update it (with no success)
When I set it to update mode and use the python tool "esptool.py", the script fails to connect to the ESP board.
Following is the command:
python esptool.py -p /dev/ttyUSB0 write_flash 0x00000 "/home/aditya/Desktop/v0.9.2.2 AT Firmware.bin"
Following is the output:
Connecting...
Traceback (most recent call last):
File "esptool.py", line 532, in <module>
esp.connect()
File "esptool.py", line 159, in connect
raise Exception('Failed to connect')
Exception: Failed to connect
I have even run the Windows counterpart of this tool "ESP Flasher" with no luck
The one who helps will be given a cookie (unless you value privacy)

Answer 1

This tool (esptool.py) works with a ROM bootloader, which is only started if GPIO_0 is tied to the GND during hardware reset. Bootloader also times out pretty fast, so just connecting GPIO_0 to the ground is not enough.
For me, following works:
Connect TXD/RXD/GND/VCC to the PC and CH_PD to VCC;
Make sure I can talk to the firmware via terminal (picocom/minicom/etc);
Connect GPIO_0 to the GND;
Connect RST to GND;
Release RST;
Run esptool.py
If still no dice, swap 5 and 6 above, i.e. first run esptool.py, then (as quickly as possible) release/disconnect RST. You will only have a second or two before esptool.py times out.

Answer 2

Try making the ground of all devices connected: if you have a level shifter inbetween, make sure the GND is tied to the GND of Arduino and also to the RS232 GND.