Forgive me, I am not an engineer but I wanted to figure out which connector I should use to program my custom mechanical keyboard design. The PCB has an Atmega32u4 controller which is connected to a 6 pin header.
I am adding more detail to my question because other members requested it so they understand my question better. I used to make custom keyboards using QMK plus Adafruit feather boards and it was easy to program them because I can just plug in a usb cable and get started.
Now, I am trying to learn how I can program a controller like the Atmega32u4 directly on the PCB. My friend helped me design the PCB and but I didn't get a chance to ask him everything about the design. I did some research and found that the 6-pin header on the PCB board is how I can program the controller. I can easily solder the header but I don't know what to do after that. I assume there is some sort of connector or cable I should be using. Thanks in advance!