ESP32 Forum

Hello,

1)We design ESP32-D2WD chip based custom board and for flash code we use ESP32-Prog UART method.

Our confusion is ESP32-D2WD Fresh chip consist UART Bootloader ?? Or we need to add JTAG as well over board and first we need to Upload bootloader using JTAG over Fresh ESP32-D2WD SOIC then we can upload code using UART method.

We have very low space and not able to add JTAG over board So Can we use only UART method over board and Can we Flash code over custom board using UART method without any JTAG or Bootloader??

I think ESP32 Have internal UART bootloader we does not need to flash bootloader just use BOOT and RST pin and Flash application code over ESP32-D2WD SOIC Custom board uisng ESP32-Prog.

2) Also Can we use ESP32-Prog BOOT and RST button pin Instead of add BOOT and RST button over main custom board???
I think just need to connect ESP32-D2WD RST and BOOT pin with ESP32-Prog by Programming header and access that button.

We use ESP32-Prog :- https://www.evelta.com/esp-development- ... LbEALw_wcB

Thanks,
AB.

Hi,

The ESP32 uses a first stage bootloader from it's internal ROM memory (you cant modify it) and this is used to load your firmware, including the second stage bootloader to the external flash.

Using the ESP-Prog, you can flash your firmware using UART method with no problem. Just be sure to keep the EN and GPIO0 pins with PULL UP resistors on your custom board.

Ok Thanks,

So no need any JTAG to upload a code I can flash ESP32-D2WD using UART directly even its custom board and Fresh chip.

Also can I use BOOT and RST button of ESP-Prog Flasher instead of place over custom board??

ESP32-Prog BOOT and RST button connect with ESP32-D2WD pin of BOOT and RST by UART programming header (There is 6 Pin over UART Header which is BOOT and RST include connection).

Thanks.

That's correct!

No need for JTAG and you can use the BOOT and RST buttons from the ESP-Prog as well.