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I am designing a PCB and I just want to make sure nothing is wrong before I send it off to the fab house. If one of you knowledgeable stack exchangers could give me some feedback, I would really appreciate it.

Here is the schematic : enter image description here

and here is the board : enter image description here

I don't have enough reputation to post a link to the eagle files, so if anyone wants them, just let me know.

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    \$\begingroup\$ 1. In the schematic, you're missing the "VCC" label at the output of your voltage regulator (on the + side of C2) \$\endgroup\$
    – m.Alin
    Sep 18, 2015 at 11:25
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    \$\begingroup\$ 2. The GND pin of your USB connector should be labeled "GND", not "GND1". It needs to be connected with all the other grounds on your circuit. \$\endgroup\$
    – m.Alin
    Sep 18, 2015 at 11:27
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    \$\begingroup\$ 3. I'm not familiar with the ATmega microcontrollers, but I'm pretty sure pin AREF shouldn't be left floating; probably must be connected to VCC. See the datasheet of the microcontroller for, it should provide a minimum schematic for the uC to work properly, including some decoupling capacitors. \$\endgroup\$
    – m.Alin
    Sep 18, 2015 at 11:30
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    \$\begingroup\$ 4. The BLUE LED1 is connected the other way around \$\endgroup\$
    – m.Alin
    Sep 18, 2015 at 11:32
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    \$\begingroup\$ There's a lot wrong with your schematic (consequently, your layout too), but I don't have the time to go through all of it right now. If someone wants to provide a more detailed answer, feel free to include my comments as well \$\endgroup\$
    – m.Alin
    Sep 18, 2015 at 11:34

1 Answer 1

Reset to default
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*Change resistor for RESET pin to 10K.

*Add a 100nF cap between AREF and GND pin.

*Add 100nF capacitor between each VCC pin of your ICs and GND.

*Connect GND pin of USB to GND.

*Connect VOS of TPS62172 to VCC!!!!

*I can't find GPSTX label! where it should be connected!

*Connect LED1 to GND.

  • Your L2 has no value, it should be 33nH.

I think revise your design...

This maybe useful: https://www.sparkfun.com/datasheets/GPS/Modules/Skytraq-Venus634FLPx_DS_v051.pdf

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  • \$\begingroup\$ Sorry. I redid the schematic in eagle after I made the board, so I didn't check that the nets were connected together. You will see that if you look at the PCB, most of your points were addressed. Led 1 does not connect to GND, but rather VCC. \$\endgroup\$
    – Mathieu pasquet
    Sep 18, 2015 at 15:40
  • \$\begingroup\$ about LED1, then you should reverse it's direction.I first look at your schematic that is faster to detect problems, then I suggest strongly that add mentioned capacitors near ICs. it was better that you attach most current schematic into this post, anyway. \$\endgroup\$
    – HOPE
    Sep 18, 2015 at 16:18
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    \$\begingroup\$ @Mathieupasquet The schematic and PCB designs should be exactly the same! Otherwise, what's the point in having a schematic? \$\endgroup\$
    – m.Alin
    Sep 18, 2015 at 21:57
  • \$\begingroup\$ Posting a schematic and PCB that don't match for design review is a waste of everyone's time. Don't do that, use your tools to verify that schematic and PCB match and if they don't fix them before posting for review. \$\endgroup\$
    – Peter Green
    Oct 18, 2015 at 23:04

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