Help recreating Arduino Mega 2560

[clutchlikemamba]

So I am doing a project which is tested using the Arduino Mega 2560. However, I cannot explicitly just use the Arduino for the final product. I have to create a PCB from scratch so my approach is to use easyeda.com to create a PCB that will have all of the components of this Arduino Mega 2560 basically imported and soldered directly to the board. The issue is, the provided schematic/PCB footprint already created has components on it which I don't know what exactly some of the components are. I would also like to remove the components and connections that deal with the USB capability for the Arduino Mega 2560 because I will be using strictly the Serial.

The recreated schematic and PCB model I am currently using is:

https://easyeda.com/hot/Arduino_Mega_2560-z92kCUO6o


Would anyone be able to direct me to a model I could use for a PCB creation that already has all of the PCB footprints or at least the exact parts with the part numbers already there?

Thank you!

[Delta_G]

This link :  https://www.arduino.cc/en/Main/Standalone

shows the minimal setup needed to build an UNO on a breadboard with the bare chip.  The concept will be exactly the same for doing the Mega except the pin numbers will be different and there will be a lot more of them.  The basic components needed will be the same.  Look at the datasheet for the 2560 to see which pins to use for everything. 

[johnwasser]

I would start with the Eagle .brd (board layout) and .sch (schematic capture)  files that Arduino provides:
https://www.arduino.cc/en/uploads/Main/arduino-mega2560_R3-ref-design.zip

Find a way to import those into your chosen PCB design software and delete the parts of the schematic you don't want to bother with (or just leave them unpopulated).

[hydrocontrol]

I did my own Mega board, because I needed some Mega2560 pins which are not available on the Arduino Mega.
If you know eagle, then the link from johnwasser is excellent advice. There is a free, limited version of eagle.
I recreated the PCB in KiCad. I used all the parts as specified in
https://content.arduino.cc/assets/MEGA2560_Rev3e_sch.pdf

Some things to be aware of:

- The atmega2560 chip is only available as SMD. So you will have to solder SMD, or get it done at some PCB manufacturing place. I use elecrow. (No advertisement intended, just my good experience with them)

- follow the advice in the atmega datasheet about connecting all the Vcc and Gnd Pins, and the blocking capacitors, and positioning of the crystal.

- your microcontroller will not have a bootloader. Include a ISP header on your PCB for burning the bootloader. You can use any arduino to build a bootloader.

- if you plan to use one of the USB-serial adaptors, don't forget the capacitor in the reset line.

- your first version of the PCB WILL have errors. Design the PCB in such a way as to facilitate troubleshooting: Expose test points, be generous with headers, don't pick the smallest SMD parts, think about the 5V power supply, include test LEDs, etc.

Good luck
Thomas