ESP32 Forum

Hello!

I'm a freelancer and I have been working on a somewhat simple ESP32-C3 project. I have developed a custom PCB using an ESP32-C3-MINI-1-N4, the module we got has the M4N4 engraving on it, the problem is that we haven't been able to download any new code, here is the log we have received from the ESP32:

21:27:05.455 -> Build:Feb 7 2021


21:27:05.455 -> rst:0x3 (RTC_SW_SYS_RST),boot:0x5 (DOWNLOAD(USB/UART0/1))


21:27:05.455 -> Saved PC:0x40048b82


21:27:05.455 -> Download boot modes disabled


21:27:05.455 -> ESP-ROM:esp32c3-api1-20210207

The strapping pins are shown to be in the right condition to make a UART download, but then it says that download boot modes are disabled. My first guess here is that these modules that we got from the PCB supplier have their eFuses pre-programmed. Is there a way to confirm if the eFuses have been burned to 1? Is there any serial we can check to confirm something like this? Is there any possibility that the eFuses are not the issue?

I haven't been able to test the eFuse Manager myself since the board is in the hands of my client, and he only has available the Arduino IDE and he doesn't have enough experience using idf.py.

Thank you in advance for your help!

Seems that chip has SecureBoot enabled. Is this something you or your customer might have done? If not, can you post a clear picture of the module, with the text and QR-code readable?

Seems that chip has SecureBoot enabled. Is this something you or your customer might have done? If not, can you post a clear picture of the module, with the text and QR-code readable?

As far as I know, if it was secureBoot the log would say something about it. Anyway, my client wouldn't have done anything like that, the project is using Arduino Core and he just tried downloading our firmware. Here is a picture of the chip, is not super clear but is understandable enough:

Thanks. I'll ask my colleague to look up the barcode on that one to see if it was supposed to be flashed+locked from the factory.

I got a response, and that's a module that came pre-flashed with customer firmware and as such has download mode disabled. I'm afraid it's not usable for anyone but that customer. Can you tell me a bit more (if needed in private email, jeroen at espressif dot com) how you came by this module?

I got a response, and that's a module that came pre-flashed with customer firmware and as such has download mode disabled. I'm afraid it's not usable for anyone but that customer. Can you tell me a bit more (if needed in private email, jeroen at espressif dot com) how you came by this module?

Thank you for your confirmation. Our PCB supplier also populated the boards, so they are the ones who know the details about how these modules got to us. Parallel to this, I was also having an email conversation with someone from espressif through our PCB supplier, they also confirmed that these boards were pre-programmed. I suppose the PCB supplier is now in talks with their component supplier since that is where the module would have come from.

Clear, thank you.

Clear, thank you.

Hey, I believe I might be having the same problem. Could I provide you with a picture of the qr code to see if it is the case?
I am unable to flash anything on my M4N4 module, and I can't seem to find any other issue/reason why my board might not work (I have not worked with any XXN4 modules before, so I cannot comment about those comparatively). IO2 and IO8 are pulled up, IO9 is pulled down with a button, and EN is pulled down with a button. Doing the correct download mode procedure (holding boot button, pressing reset button, releasing boot button) gives me a JTAG and COM* connection on Windows 11, however, esptool stops at `Connecting...` and gives me write timeout.

I would appreciate any help, and sorry for bumping up an old post, I could not find any way to contact you directly ESP_Sprite.

No issue. I'll give you the reply from my colleague when they're back in a few days. What you could do is to start a terminal emulator on the serial port (115200,n,8,1) and reset the chip into bootloader mode: if this is a locked module, it likely says 'Download boot modes disabled' on the serial port.

Hey, I believe I might be having the same problem. Could I provide you with a picture of the qr code to see if it is the case?

That's indeed a module that is preflashed for a customer and has download modes disabled. Can I ask where you obtained it?