We went through this with XMC Flash Chips and about 3000 Wrover-E modules in the field. Good news: You can fix this permanently in your next firmware update Bad news: You have to do it before the problem hits you. TL;DR: XMC Flash chips can be write protected, and their status registers, too. That's...

So do I understand this correctly?

When some of our WROVER-E boards boot, they provide the flash with 1.8V instead of 3.3V?
And they show in the boot loader that GPIO12 is reading HIGH on startup? (boot:0x33)
And this happens although we've set the Fuses that force VDD_SDIO to 3.3V?

I see. Now there's a problem. I've pinned SDIO voltage to 3V3 by burning the appropriate fuse, and as it seems, the bootloader does not pick that setting up, setting the flash to 1V8? Are we talking about these fuses? espefuse.py --port /dev/ttyUSB0 summary XPD_SDIO_FORCE (BLOCK0): Ignore MTDI pin (...

Hi all, what is the intended reason and cause for RTCWDT_RTC_RESET on boot? I had some WROVER-E Modules dying in the field with an RTCWDT_RTC_RESET boot loop after weeks of proper operation. Sadly, the module does not recover by re-flashing the module like in the first thread below. My hope would be...

Ritesh, could you please scan the QR Code on your faulty WROVER modules? Simply use any qr code scanner software. You will receive a 18-digit number. The first 2 digits tell you the fab, the next 4 digits are the manufacturing date YYWW and the rest is just a MAC address. Then when you have it, we m...

This is how the problem looks at our failing modules. ets Jul 29 2019 12:21:46 rst:0x10 (RTCWDT_RTC_RESET),boot:0x33 (SPI_FAST_FLASH_BOOT) configsip: 0, SPIWP:0xee clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00 mode:DIO, clock div:2 load:0x3fff0030,len:380 ho 0 tail 12 room ...

I'm also investigating flash corruption. It simply happens in the field, even after weeks. (WROVER-E Modules with 16MB Flash) I'm experiencing a reboot loop (?) with RTCWDT_RTC_RESET, too. However, I was not able to recover the chip by deleting the flash. Is there any way to recover? Or are the modu...