Firmware Update Problem

[Jan Kijonka]

Hello,

I had ESP12-E AI-Thinker (AI Cloud Inside) module which had AT firmware from 2015. I had no problem to update firmware via UART (Tx + Rx) with GPIO0 connected to GND. Now I have ESP12-E from another vendor without AT command firmware and I can't update firmware. I use ESP8266 Download Tool v3.4.8.

Log form ESP Flash Download Tool:
Connecting...
raise in device connect
chip sync error.
baudrate sync fail ... retry ...

I can read device ready in Serial Port Terminal on baudrate 74880 (GPIO0 connected to GND):
ets Jan 8 2013, rst cause:1, boot mode:(5,7) --- sometimes boot mode:(5,0)
waiting for host

And I can read device ready in Serial Port Terminal on baudrate 74880 (GPIO0 connected to VCC):
ets Jan 8 2013, rst cause:1, boot mode:(7,0)
waiting for host

How can I update to AT command firmware ?

Thank you,
Jan Kijonka

[pratik]

I think you are not setting the boot mode right. You should keep your terminal open and make sure you boot into mode 1. Not 5, 5 is for SDIO mode.
To enter UART mode for changing firmware, make sure of this:
[GPIO15，GPIO0，GPIO2] = [0, 0, 1]
GPIO 15 and GPIO 0 must be both low.