A few days ago I successfully programmed ATmega328 via bluetooth. But I need 8 or more analog inputs so I immediately thought of ATmega32u4. Can I program the microcontroller through UART, not usb?
I apologize for my English.
The bootloader for the Lenoardo and the Micro uses a software serial port via the usb.
You could make your own OptiBoot loader to use the serial port.
Even the ATmega328p has 8 analog input, only not the DIP version. I have a Pro Mini clone with A0 to A7.