ESP32 Forum

It's powered from a 1A supply, so it should be sufficient. Just to check, I changed to a 3A lab supply, and the result is still the same.
But I came across this link about ESP8266 having the same problem. It was solved by using a different USB to serial converter. Although my FTDI serial converter is bought at Farnell, It may be worth a try..

Thanks for the help so far!

@RoundRobin were you able to eventually figure out a solution? Did changing the USB-Serial adapter work? I'm having similar issues

esptool.py v2.1-beta1
Connecting........_____....._____....._____....._____....._____....._____....._____....._____....._____....._____

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

@RoundRobin were you able to eventually figure out a solution? Did changing the USB-Serial adapter work? I'm having similar issues

esptool.py v2.1-beta1
Connecting........_____....._____....._____....._____....._____....._____....._____....._____....._____....._____

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

Hi,

First of all check GPIO0 connection which should be LOW to enter module into program mode.

Once you have checked and confirmed that then check USB cable is pooper using which you have connected ESP32 based board.

Which ESP32 based Development Kit are you using? Or using your own ESP32 based board?

Can you please check that are you able to read flash and chip I'd using esptool.py script? So that you can be clear out that module goes into program mode.

If module goes into program mode then you need to check baudrate at which you are flashing image. Generally, I got this type of error at higher baudrate which is 912600. So, I am generally using 115200 lower baudrate for image flashing purpose.

Let me know if you are still facing same issue.

I also have similar problem. I try to download a program to ESP-WROOM-32. The module is on a board. I use Arduino IDE to download. Everything seems to go well but after I remove power from board and remove ground jumper from IO0 and power the board there is nothing in Serial monitor. After resetting (EN pin to ground) the program sometimes starts to run. Sometimes error (rst:0x10 (RTCWDT_RTC_RESET),boot:0x33 (SPI_FAST_FLASH_BOOT)
flash read err, 1000
Falling back to built-in command interpreter.
OK
>ets Jun 8 2016 00:22:57)-

Do you have other connections to your WROOM32 module?

Yes, I have a DWM1000 UWB module. I have read many comments and I have noticed that ESP32 is quite picky on the power supply. I have a 500mA v-reg.

Not sure if I sent reply. But I have Decawave's DWM1000 connected via HSPI. I use 500mA vreg. I also plan to attach Adafuits LSM9DS1 board to this same board.

I'm having problems too. I'm using a custom circuit, and I have a 500mA reg and have tried it with a bench power supply. When trying to flash or read_flash_status I get UART signals back and forth look ok on a scope (though I haven't recorded the data in detail)

Any ideas gratefully received?

I've changed USB->UART convertor and now things work. I'd still like to work out why the other convertor did not work, so would still welcome suggestions as to where the error comes from.
THanks

Answering my own problem, I found that the difference between the USB->UARTs was how they handled a block of characters sent in sequence (so probably something related to buffering in them). My advice to others would be to loop back TX to RX and then compare what esptool was was trying to send, to what was actually going down the serial line. Shockingly mine was dropping characters when esptool sent a block all at once. Typing on a keyboard was slow enough for it not to be a problem.