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By Victor ADASCALITEI
#75613 Hi guys,
I'm sorry if this was asked already. I did search it, but nothing popped up on the forum.

So my problem is like this:
I made a custom PCB with an ESP8266EX and an Adesto 8Mb flash memory. I have checked the power rails and they are 3v3 as expected. Basically, I followed the official hardware reference guide

The problem is that the ESP cannot communicate with the external flash memory. When using esptools to read the flash_id I get manufacturer 00 and chip id 0000. If I query for the chip_id, I can successfully read the esp chip id. The console does show the boot mode correctly points to flash boot.

One thing I noticed which I found strange is that, when idle (just powered on), SD_CMD pin reads a garbage value: around 2V which is outside the permitted range. These 2V are read with or without the flash chip being connected.

Any ideas of what might explain this behavior? Any help would be highly appreciated.

Cheers for a wonderful community! 8-)