I also had trouble flashing the ESP8266 from firmware "0018000902-AI03" to "0.25.0.0". I was using esptool on a mac, and it would look like it was working and get to "Uploading stub...", then it would fail with error "A fatal error occurred: Timed out waiting for packet header".
I tried many things, and finally got it to work by decreasing the baud rate from 9600 down to 57600.
For others experiencing this problem, the steps below worked for me:
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I also had trouble flashing the ESP8266 from firmware "0018000902-AI03" to "0.25.0.0". I was using esptool on a mac, and it would look like it was working and get to "Uploading stub...", then it would fail with error "A fatal error occurred: Timed out waiting for packet header".
I tried many things, and finally got it to work by decreasing the baud rate from 9600 down to 57600.
For others experiencing this problem, the steps below worked for me:
1) Pin connections:
[ESP8266 ---> USB-TTL adaptor]
GND --> GND
UTXD --> RXD
GPIO2 --> [none]
CH_PD --> 3.3V
GPIO0 --> GND
VCC --> 3.3V
URXD --> TXD
2) Downloaded firmware ESP8266_AT25-SDK112-512k.bin into my Documents folder
3) Downloaded and installed esptool.py using terminal:
4) In the terminal found my tty port using
For me, I found it was /dev/tty.usbserial-AI06B7Y6
5) I then ran the esptool from the terminal:
It spit out a bunch of stuff and finally finished with:
Hash of data verified.
Leaving...
Hard resetting via RTS pin...
6) To verify, I followed the firmware test in Espruino IDE as described here, and it verified 0.25.0.0.