Bare bones Atmega2560 design with usb on board help

[darcy_d]

Hi all.
I have designed a custom pcb and have made a prototype currently an Arduino Mega to test ( it was designed using an ATMEGA pin layout to connect with the rest of the board so had to desolder the header pins and solder the mega to the custom pcb which was a little bit of work to desolder all the pins and add it to the new board.

I am now at a stage where it all works well and i got the main prototype done but i need to get the boards produced as an assembled unit now without the Arduino mega so i can cut out my labor time assembling each board and reduce size so basically need to design a bare bones Mega.

I need to include a usb interface on the board still ( to be able to update as software updates or future bugs are solved and make it easy to just plug in via usb to the board i don't want to have headers and another tool to do this as each board needs to have what is required on board)

I have seen a few bare atmega designs but they all use an external header to usb of some kind which i don't want to have to include a separate programmer board or anything in the finished product just a usb cable ideally.

Does anyone know where i start with this or where i can find this information out?

Thanks,
Darcy

[6v6gt]

The normal definition of bare bones excludes extras like a USB connection.
Look for a schematic of an arduino clone (say nano or uno) which uses a CH340 usb/uart chip and copy that part for your Mega project.

[westfw]

@darcy_d

Does anyone know where i start with this

An Arduino Mega doesn't have a lot beyond "bare board", aside from a lot of connectors. Just start with the published MEGA board, and delete parts till you are happy.

I like to use modules for USB connectivity. For about a buck from Aliexpress, you can get a USB/Serial module that includes microUSB connector, Power and traffic LEDs, and isn't much bigger than a USB-B connector. Sort of like this ATmega128 design