Arduino Forum

Development => Other Hardware Development => Topic started by: bos1714 on May 25, 2018, 02:25 pm

Title: Modified Mega2560 Board
Post by: bos1714 on May 25, 2018, 02:25 pm
Hi everyone! I am designing a modified version of the Mega2560 and I believe I am finished with the layout. I was wondering if anyone could help me by going over the board and schematic files to check for any errors that might happen. I used AutoDesk Eagle for the schematic and layout.

If you would be so kind, please check for the following issues, which I think may be problematic but I'm not sure:
-Transmission lines from USB to converter to Mega2560 chip to make sure that they meet all transmission trace guidelines
-Rx/Tx lines from chip to connector pins
-Regulator circuitry to make sure it is correct. (i tested it on protoboard and it works)
-Any circuitry that the IOref and Aref pins need to make sure the board operates at 5V
-Any other silly mistakes that a layout noob like me usually makes.

On the schematic, there are components related to overvoltage protection. I could not find the exact part in the libraries so I used 0603 capacitors just to make sure that the pads are the correct dimensions.

Attached are the eagle project, board, and schematic files, as well as a zip of the gerbers.

I was thinking of ordering the boards either through OSHPark or SeeedStudio. If you know of any other small-quantity fabricators please let me know.

Thank you in advance for any help.

Edit: I am making new packages and symbols for the over-voltage/current components, and will upload new files when done.
Title: Re: Modified Mega2560 Board
Post by: bos1714 on Jun 05, 2018, 01:54 pm
I found one of the silly mistakes I was talking about. The 3.3V regulator was taking its power from the Vin port. Therefore, It would not work if the board was powered by USB. I moved the connections so that the 3.3V regulator is powered by the 5V regulator.
Title: Re: Modified Mega2560 Board
Post by: bos1714 on Jun 25, 2018, 10:49 pm
So I finally got the courage to order the boards. Attached are the Eagle files that I sent to OSH Park. I have already begun to work on some revisions. Let me know if you notice anything.