I have uploaded Caterina.hex into ATmega32U4 by USBasp, but couldn't found the USB port in Arduino IDE, so I couldn't upload sketch into it, what maybe the reason?
The tutorial I used:https://electronut.in/bootloader...
The bootloader I downloaded from:https://github.com/sparkfun/SF32...
If using Linux try lsusb to see details of USB devices that are connected/active - does the 32U4 DFU even appear there?
If in Windows get usbdview.exe https://www.nirsoft.net/utils/us... which will give you lots of details about whether the device is even being enumerated.
Please show a photo of your pcb and schematic.
I uploaded a photo, while it prompted I hasn't been authorized.
I found the reason - I have not connected UVcc and VBus.
Good to hear. Now please mark the solution - see Tip #5 in my signature, below:
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