ForgeMatrix DTU v5.0 not flashable

[dchristl]

Hello everyone,

I hope I can get some help here. I bought an openDTU on Battery device on Ebay some time ago. It is equipped with an ESP32 S3 (8 MB Flash), NRF24L01+ PA and an Ebyte CMT2300A. The device worked fine until I updated the software. All settings were retained, apart from the pin assignment (pin_mapping.json), which was gone. Unfortunately, I don't have a pinout for the board and the seller won't get back to me either.
After I imported a pin mapping from the openDtu project, I could no longer access the device and could no longer connect to the access point. The only way was to reset the device completely. That all worked, I just had to set it up again. I then imported the next mapping file and unfortunately nothing works anymore. The serial output is not sending any data and no connection can be established via esptoo (OS error). Tried with several OS, cables, etc.
Therefore, I cannot reset the device. I assume it is in a boot loop and then always disconnects. Unfortunately, I also cannot drag the GPIO0 to GDN as it is not visible in order to enter download mode.

Unfortunately, I'm running out of ideas and don't know what to do next. Is there a way to bring the device back to life without desoldering the chip? Attached are pictures of the board. Does anyone know of such a board or does anyone have documentation on how to get into download mode?

Many thanks, Danny

[Manos1966]

Can you contact the person that sold you this hardware and ask him for the Pinout?

[stefan123t]

Can you check to contact them via their website ?

https://forgematrix.de/contact/

Umfortunately your picture of the board is rather unsharp. Also you may need to provide shots from the backside of the PCB too.
I only saw the Reset Button SW1, an SPI/I2C Bus 4-Pin Header and another 8 Pin Header.

You would need to have an ESP32-S3 Module Pin out diagram for the SoC Module which holds your ESP32-S3 to find the GPIO0 Pin to hold to GND.

Debugging this may be easier via Discord, though people maybe reluctant to help you, because it is not an officially supported and known board.
Search for "OpenDTU Fusion" board if you prefer to get a well designed board supported by the Community.

[dchristl]

Thank you for your answers, unfortunately I could not reach the provider. But I found out how to delete the flash myself. The button must be pressed and then the cable in, then I could execute erase_flash. I had to try several times, then it worked. Thanks for your help anyway.

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