Upload to ESP32-wroom-32UE

[Zyberbob]

Hi.
We have a pcb made with a ESP32-wroom-32UE
The RXD0(34) and TXD0(35) have been connected to a pin header, so we can connect UART,
We have a USB TTL we connect the GND, TX and RX
I can read the chip without any problem, but when we try to write/upload, It can connect

esptool.py v3.0-dev
Serial port COM9
Connecting........_____....._____....._____....._____....._____....._____.....____An error occurred while uploading the sketch
_

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

We are new to ESP32 in this fashion with a custom pcb board
I have uploaded sketch to NodeMCU dev boards with a onboard usb interface without any problems.

My fear is that the developer of the pcb board, have not attached or forgotten something so we can upload a sketch simply and easy with the UART

Hope someone can shed some light on this

[ESP_Minatel]

Hi,

Can you share the schematics?

[ESP_Sprite]

You need to pull GPIO0 low and then reset the ESP32 by pulling EN low momentarily. Normally a devboard has functionality like that built-in controlled by the USB-serial chips DSR/DTR pin, but if your PCB does not have that you need to do it manually.