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Topic: Modified Mega2560 Board (Read 691 times) previous topic - next topic

bos1714

May 25, 2018, 02:25 pm Last Edit: Jun 21, 2018, 08:59 pm by bos1714
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.
Time line? Time isn't made out of lines. It is made out of circles. That is why clocks are round.

bos1714

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.
Time line? Time isn't made out of lines. It is made out of circles. That is why clocks are round.

bos1714

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.
Time line? Time isn't made out of lines. It is made out of circles. That is why clocks are round.

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