Bricked KNOMI v2

[mkryuchkov]

Hello!

Flashed my KNOMI v2.2.0 with rs-flasher. What I have for now:

TL;DR;

• Menu not working, only homing animation works, cycling voron and idle face other time;
• Can't flash back to stock (black screen)

Original:

• web interface and settings (wifi, hostname, etc.) working
• KNOMI is showing Voron logo and idle face animations one after another in infinite loop (is it boot/crash loop?)
• klipper config brake macroses, but managed to send homing status
• KNOMI is showing homing animation
• KNOMI has never responded to touches and I haven't see menu at least once
• KNOMI can enter flash mode and PC sees COM device
• Can't flash with ESP32 flash tool having COM FAIL error not btt FW nor 2.2.0 full one.
• Can't flash with rs-flasher having Firmware flashing error! // Error while connecting to device
• Got OTA success trying reflash through web interface. Got logo/face loop again when not connected to klipper and homing animation when connected.\
• Got "Hello" screen after OTA flashing littlefs.bin as theme. All settings reset also. Can't flash any way also.
• Tried to OTA flash btt fw, partitions first (ok) and fw second; got stuck on 51%, screen flashing white like old TV; No changes after reboot

KNOMI seems to be broken. What happened? What possible solutions are?

UPD. Found a way to flash microcontroller via ESP32S3 Flash Download Tool as described in official wiki; Not starting up, red LED light/black screen.

UPD. Figured out how to flash with esptool, flashed firmware_full.bin. Got cycling animation state.

[DiverOfDark]

Hi!

TLDR; - this fork is originally based on V1 firmware (even for V2) - meaning it doesn't support menu / touchscreen (yet, maybe?), and it is mostly rewritten from scratch - so it's not an easily interchangeable with original one.

KNOMI is showing Voron logo and idle face animations one after another in infinite loop (is it boot/crash loop?)

It is not, it is expected behavior from Knomi V1

klipper config brake macroses, but managed to send homing status

Could you elaborate here a bit - what exactly did broken and what did you change? (this also might be the reason why you get strange behavior later)

If you want to revert to original BTT firmware - I'll try on my device and will try to write a guide on how to flash original fw.
Good news is - you can't brick device alltogether - esp32(s3) are really errorprone, but also they are not very friendly for non-developers. Probably you'll have to use esptool to flash partitions and fw from original fw.

[mkryuchkov]

Managed to build and flash stock firmware

[mkryuchkov]

@DiverOfDark Thank you for reply!

Yeah, I didn't see it implements V1 features only, my bad.

Macroses. I figured out these are just examples for override. Since I use my own overrides I have to adopt them adding knomi commands in there. I just tried to copy-paste as manual intended.

It would be nice to have a guide or some predefined options like menu-option in rs-flasher you made. Can help here, as I managed to do that.

Yeah, S3 is more user friendly than I expected. Can be software enabled to flash mode and hard to kill by incorrect FW. Saved me :)

[mkryuchkov]

How to revert to stock.

• Get bootloader, partitions and firmware bin files from official repo (v1, v2). Or you can build it yourself from sources.

• Get proper usb driver for windows (was necessary in my case). Your device should be okay from OS point: COM device without any errors.

• Get flash tool of choice

  • esptool (CLI, universal option)
  • flash download tool (windows only, mentioned in V1 btt guide)

• Flash firmware

  • For V1 you may use official guide as is

  • For V2 you may use the same BUT

  • Choose esp32s3 instead of esp32 starting the flash download tool

  • Use 0x0000 offset for bootloader instead of 0x1000

  • Both could be flashed with esptool write flash command. Here is example for DiverOfDark's full fw for V2 (zero offset):

    .\esptool.exe write_flash -e --verify 0 ..\knomiv2\firmware_full.bin

Build firmware is not necessary since you may use prebuilt ones from BTT repo or this repo. In case you are interested in just google PlatformIO + VSCode + ESP32, there are some good videos on YT.

[DiverOfDark]

I'd like rs-flasher to be able to restore original BTT firmware - so will reopen this ticket for that feature.

[DiverOfDark]

Will be in next release as part of rs-flasher. Related PR - https://github.com/DiverOfDark/KNOMI/pull/242.