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.

  • 1
    \$\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
  • 1
    \$\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
  • 1
    \$\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
  • 1
    \$\begingroup\$ 4. The BLUE LED1 is connected the other way around \$\endgroup\$
    – m.Alin
    Sep 18, 2015 at 11:32
  • 1
    \$\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


*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

  • \$\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\$ 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
  • 1
    \$\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\$ Oct 18, 2015 at 23:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.