ESP8266 Community Forum

I'm trying to update my ESP8266 ESP01 with a new firmware.
I've no UART tool so I'm using an Arduino Mega ADK as bridge connected using a level shifter.

When I use the esptool.py tool for flashing the new firmware it stops during the initial sync phase.
Looks like the ESP is not responding.

I've tried with the Serial monitor too see what it send when it boots and I got the following results:

• When I wire GPIO 0 to GND and GIO 2 to Vcc, after a reset I get this string:
  
  
  Code: Select all ets Jan  8 2013,rst cause:2, boot mode:(1,7)
  
  
• When I wire GPIO 0 to Vcc and GIO 2 to Vcc, after a reset I get this string:
  
  
  Code: Select all ets Jan  8 2013,rst cause:2, boot mode:(3,7)

ets_main.c

In both modes when the esptool sends the SYNC op the ESP seems not responding.

Any idea?

wiring or power

If it is wiring why I can receive the boot messages?
Idem for power. I'm using a separate power supplier and I've added also a capacitor.

I'm a big fan of including photos of your circuit as from time to time weve been able to see the problem in wiring. As for power, what voltage is the TX line of your UART sending? You need to make sure that the input to the RX on the ESP8266 is 3.3V and not 5V.