I created a PCB for a project and the main chip is the atmega32u4. I have tried burning the Leonardo Bootloader to it using an Arduino Uno with Arduino as isp for the programmer. The Uno has the ArduinoISP sketch uploaded to it. The error is "Yikes Invalid address of 0X00000".
I realize I have missed some components and connections on the Atmega32u4, but I have now fixed them.
The schematic: Schematic_Ultimate Weather_2021-08-29.pdf (185.9 KB)
Sorry. Yes, SCK, MISO and MOSI are not attached to a pin header for programming. I have now managed to solder a 3 pin male header to those three pins for burning the bootloader. I have also added a 1µF cap from uCap to GND, and attached VBus to +5V.