The MCP1700 can only deliver 250mA. We highly recommend feeding ESP chips with a power supply capable of delivering >=500mA.

Yes, SiP is also included in 'off-chip' flash. Whether the packaging itself already is enough protection depends on your threat model, see e.g. here for a demonstration (on STM32 clone chips) where it might not be.

You can look at the EXCVADDR in the stack dump. I'm going by heuristics from seeing lots of valid addresses during my years at Espressif and going like 'this ain't one', but you can check the memory map in the TRM if you want to be sure. (Generally, valid addresses tend to start with 0x40 or 0x3f.)

All the things wrapped in ESP_ERROR_CHECK are functions; they need to be called within a function, e.g. your app_main. You can't just plunk them anywhere in your C file.

You can add the Arduino libraries/functionality as a component to ESP-IDF. You'd still have to rework things like your build flow etc, but your code can mostly stay the same.

Looks like the address that is dereferenced is garbage. That's usually a memory corruption done earlier in the code somewhere.

IO0 does not and should not have a capacitor on devboards. In ESP32_DEVKITS_20190621.pdf, that capacitor is marked as NC meaning there is a footprint for it on the PCB but it's not placed. Some people read over that and copy the capacitor, and the effect is that the chip will always boot up in downl...

Thank you so much, very kind If i use usb-to-serial converter is there any routine to be executed (pulling up or down any pins or something similar)? As I said, you probably want to be able to pull GPIO9 low for the initial flash. Moreover, if i'm working on arduino project, is there a way to make ...

Generally, the Espressif devkit-C series are widely available and generally kept up-to-date with the latest SoC. Do note that we generally do not recommend using devkits as final products, as the composition of devkits isn't as stable as e.g. a module or chip. (As in: we won't change things in modul...

No, sorry, there's no way to do that. You could possibly get a few pins that run at 1.8V by doing some hackery with the pins in the Vcc_sio domain (but note that means moving the flash to custom pins, which you can only do using external flash), but that's way less than 25 IOs and still not at the 1...