ESP32-C3-DevKit-Lipo Rev.A and Rev.B differences ?

[winfried]

Doing coding for the very impressive ESP32-C3-DevKit-Lipo from you, I saw there is a new revision B as schematics:

- no reset button anymore, but now a user button

to be curious: what was the reason of this change ?

Is there any other differences ?


all the best
   winfried

PS.: Are C3 boards in stock Rev.A or Rev.B if I order now ?

[LubOlimex]

It is more of a boot button. We had space for only one button and based on customer feedback we decided force boot button might be more useful than reset. Reset button is not really needed when you can just disconnect the USB. While boot button can be needed when you want to force bootloader mode (in case you've bricked the automatic boot somehow). So to force bootloader mode in revision B you'd need to hold down the button pressed and apply USB, then release the button. In revision A you'd need to place own button on GPIO9 to force boot mode in case bootloader bugs out (but you don't have a reset button if your user program bugs out).
 
> Is there any other differences ?

Nothing as significant as the button change.

> Are C3 boards in stock Rev.A or Rev.B if I order now ?

Revision A is still in stock. At the moment we haven't manufactured any revision B boards.

[winfried]

Thanks for the Information, good to know.

Ok, so I see ESP-Prog has also the GPIO9 connected.
So I am curious, is GPIO9 used for the ESP-PROG to debug ?

Also, I am more curious, how can I brick the automatic boot, via the serial
upload on C3 ? Did this happen sometimes ?

mfg winfried

PS.: I will prepare a reset button option, in case I need it for my LEMiot getting Rev.B.

[winfried]

So I am curious, is GPIO9 used for the ESP-PROG to debug ?

Also, I am more curious, how can I brick the automatic boot, via the serial
upload on C3 ? Did this happen sometimes ?

Ok, stupid question, I kind of "bricked" it myself, (not using an ESP-Prog-C):

It is not really "bricking" since USB is no serial Interface by default, only with factory firmware it shows up as serial without pressing boot button at power up/reset.

It also answers the question, GPIO9 is used by upload (at least with platformio/arduino i tested).

thanks,
  winfried

[LubOlimex]

I think one of our engineers managed to somehow bug it accidentally by downloading some code that modified the pins related to the USB or something I am not sure.

Just if it happens that you can't download code via the USB - you disconnect USB, establish a connection between GPIO9 and GND (via button or via wire), apply USB, remove connection between GPIO9 and GND and you'd be able to download code.

[winfried]

Thanks for the info, good to know.

Anyway since I use:

Code Select Expand

board = esp32-c3-devkitm-1 in platformio, and the DEVKITM-1 board from Espressif [1] has a USB-UART bridge handling RST and GPIO9, I mixed them up.

So I am wondering what is the suggested "board" in platformio, since I see esp32-c3-devkitc-02 is also with UART bridge, or does it not matter ?

mfg
 winfried

[1] https://docs.espressif.com/projects/esp-idf/en/latest/esp32c3/hw-reference/esp32c3/user-guide-devkitm-1.htm