My esp23 was working fine running espruino, but after doing some interfacing which seemed to work I now can not connect to it via the ide. I decided to reflash as a similar thing had=s happened before when I used the esp8266, and reflashing sorted it.

However using the esptool I just get:
esptool.py v2.3-dev
Connecting........__.............................................__

A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header

I had this working, its an esp32 dev board with a boot and rest button. I think its an espressif dev c board. I did not touch the buttons before when I initially loaded the esspruino onto it.

Any help appreciated or have I bricked the device?

Thanks in advance

Try Putty at 115,200 Baud

Connect with Putty

Press reset (or momentarily ground the reset pin)
The output should look like this: (but look for errors)

ets Jun  8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
ets Jun  8 2016 00:22:57
rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0x00
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:QIO, clock div:2
load:0x3fff0008,len:8
load:0x3fff0010,len:1932
ho 0 tail 12 room 4
load:0x40078000,len:10012
load:0x40080000,len:252
entry 0x40080034
 _____                 _
|   __|___ ___ ___ _ _|_|___ ___
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v95 Copyright 2017 G.Williams
Espruino is Open Source. Our work is supported
only by sales of official boards and donations:
http://espruino.com/Donate
>

Ground GPIO 0 pin and do a reset
The output should look like this.

>ets Jun  8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
ets Jun  8 2016 00:22:57
rst:0x10 (RTCWDT_RTC_RESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2)
waiting for download

Hi I cannot connect with Putty or any other serial monitor. The espressif boot writer gives the following output:

CONNECT BAUD: 115200

.....__.............................................__[2018-02-05 20:12:36,078][ESP8266Loader_spi[1]][espDownloader.pyo][line:351][ERROR]: Chip sync error: Failed to connect to ESP32: Timed out waiting for packet header
[2018-02-05 20:12:36,079][ESP8266Loader_spi[1]][espDownloader.pyo][line:395][ERROR]: ESP32 Chip sync error esp_sync_blocking.

Not sure if it helps though.

Any help appreciated Thanks

Other than trying all the baud rates, can't think of anything else.
Try 9600,19200, 38400, 57600, 74480.

Did you ground GPIO 0 and do a reset to put the chip into flash programming mode?

Connecting........ __ ............................................. __

The ESP32 is not in flash mode, check section The actual flash

Do you have anything connected to D0? That might be affecting the reset usually done by the dts/cts lines.

Hi thanks for the comments, its a ESP VROOM-32 dev board with boot with two buttons boot and en. I've tried varios combinations of the buttons. when writing or trying to erase with no success. As I mentioned previously it worked without touching these. I checked the 'Actual Flash' section and that implies that this would be the case. So I am of the opinion, I am stuffed.

I assume there is no other tool other than the esptool to write to the device?

On the upside, for them, there is a happy ebayer in china who has had an order for a new one.

Thanks for all the help given.

The other thing to try is the erase_flash option of esptool.

Hi thanks for the suggestion, erase also uses the esptool, so I get the same problem:

....\esptool-master\esptool.py --port COM9 --baud 115200 erase_flash
esptool.py v2.3-dev
Connecting........__.............................................__

A fatal error occurred: Failed to connect to Espressif device: Timed out waiting for packet header

Thanks for your help.

Try it without specifying a baud rate. I think ESPtool.py will try and find one that works.
For example this batch file to read the chip info:

:: Read ESP8288 or ESP32 chip info
set /p pport=Enter a Com port 
echo %pport%
pause
esptool.py --port %pport% --no-stub chip_id
esptool.py --port %pport% --no-stub read_mac
esptool.py --port %pport% --no-stub flash_id
pause

Still the same response I'm afraid.

....\esptool-master\esptool.py --port COm9 --no-stub chip_id
esptool.py v2.3-dev
Connecting........__.............................................__

A fatal error occurred: Failed to connect to Espressif device: Timed out waiting for packet header

I think we can say there is no response.

Thanks again for the support.
Richard

It's sounding like it really is a brick.
What do you have it connected to?
Chip, power, USB cable?
Other circuits?
Use Voltmeter to confirm 3 Volts. Do the LEDs flash when you plug it in?
Is the USB cable functioning with some other device?
If connected to other circuits can you disconnect and try it?
Certain pins have to be at the correct levels to program the chip.
Some other pins may be used by the SPI mode to talk to the flash chip.

If you are using an Arduino kit to program it does the kit work with another device?

Also put you finger on the chip - is it overly hot?

As far as flashing goes - there is an espressif exe for windows you could try.

Try to use another port (instead COM9). Under Linux use esptool.py --port /dev/ttyUSB1 --no-stub chip_id (instead ttyUSB0)

I found https://www.esp32.com/viewtopic.php?f=2&t=4912

I see that this is an old post, but just wanted to let any future frustrated person with the same problem know this:
I had the exact same problem, and what fixed it for me was to reflow the pins on the esp32 processor itself. Obviously one of the pins had lost connection.