By default, the JTAG is connected to the internal USB-serial-JTAG converter, accessible over the micro-USB port labeled 'USB'. You can use that, but if you do not want to, you need to blow an eFuse to change that. The docs do a pretty good job at explaining the details.

Purely looking at the HTTP protocol itself, you could either use a HEAD (instead of a GET) request to get only the headers of the page and then look at the 'last-modified' header, or you could use an If-Modified-Since field to tell the webserver to only return a result if the file has changed after ...

As long as you don't use any of the WiFi or BT functions, you should be OK.

What a curious bus. Yes, at first glance I think this should be doable. You can use the GPIO matrix to net you a 2nd inverted MOSI /SCK output for the SPI bus, giving you a differential signal without external components. Current/voltage limiting on the differential pairs can likely be done using se...

Not exactly what you want, but perhaps the rollback feature is good enough?

Pico-D4 always is v1 silicon, from what I know. You probably want to migrate to Pico-V3, which always is V3 silicon. Do keep in mind that some things are changed between the two (check the V3 datasheet, it has a list of changes).

Then how are you flashing the binary? Are you invoking `idf.py flash` or using esptool.py manually?

How are you compiling this example? Normally, you'd expect esp-idf to use the component manager to automatically fetch lvgl. Can you run `idf.py reconfigure` and see if that resolves the issue?

USB actually is 3.3V on the datalines. Only the power is 5V.

Note that this forum is for ESP32 chips and their ilk, but since your question could also be applicable to e.g. an ESP32C3 which also has a single core: In our SDK, the WiFi and user code parts are linked into the same executable, executed by the same CPU. FreeRTOS is also linked into that executabl...