Testing PCB design (Beginner to Eagle)

[Anonymous]

Hi guys,

This is my first attempt at Autodesk Eagle and PCB designing, so I'm sorry if these questions are obvious or dumb. I just finished my first board and I'm kind of confused on what the next steps are. So I just wanted to ask a few questions:

1.) How do I know if it's designed correctly and can you test the design in Eagle? 

2.) Could I send this deign to a company to get in manufactured?

The design is essentially an Adafruit Trinket M0 with two MAX9814 amplifiers and five JST connectors. I used the Eagle files provided by Adafruit, so most of the connectors were provided. I'll post my schematic and board files just in case anyone wants to look at it. I'm using eagle 9.4.1 and any advice on how to improve my design that could help me improve as a PCB designer would be appreciated. Thanks!

[havlicek6TH3H]

Hi,

There are two basic checks - ERC in schematic and DRC in board file. 

ERC checks schematic and DRC checks board. Try to press DRC button and press check you will see some errors in your board. Some warrnings are critical - airwires, collision between battery and USB connector etc.

There is lot of things to improve try to take a look at some similiar design and you will see what could be improved (Try to use wider traces for power supply and ground, connect traces to SMD pads in the better way etc..) Try to take a look at some video on youtube how to design PCBs generally. It looks like you know how to work with Eagle but you need some PCB feeling 😄

Finally yes, you can send data from Eagle to PCB manufacturer - you need to generate CAM data (gerber) but after you repair your design.

Best regards, 

Vojta

[Anonymous]

Vojta,

I appreciate you getting back to me and the advice that you gave me. Do dimension warnings have to be fixed, because that seems to be the majority of the errors after the check. I'll fix the airwires and the collision errors and I'll post the new board files to see if the new design is better.

Thanks

Patrick

[havlicek6TH3H]

Hi,

most of dimension errors are just that the holes for screws are near the traces - its possible bug when you need to attach the PCB.

Ciritical dimension errors in your design are caused by overlaping USB and slot for battery.

Dimension rule is set to 40mil - every object has to be 40 mil from dimension. You can change it in DRC - Distance - Copper/Dimension.

Vojta

[Anonymous]

Hi Vojta,

Sorry that I am just now getting back to this. I believed I fixed the collision with the USB connector and the battery, as well as the airwire errors. However, I can't fixed the dimension errors that the holes are causing by the USB connectors. It won't let me delete them for some reason and I can't generate cam data until the design can pass the DRC. Any reason why it won't let me?

Thanks

Patrick

[one-of-the-robs]

Where did you get the USB connector library part from? It looks to me that most of those dimension errors are down to the way the footprint has been designed. You can reduce the number of errors if you allow smaller clearance to the dimension (board edge) - check what your chosen board house can do but Eagle's 40mil default is generous.

I would route N$13 round the outside of CN1 instead of under it. That will remove some of the other errors. It's also shorter and neater.

[havlicek6TH3H]

Hi,

I can take a look at 8pm.

[Anonymous]

Hi,

I got all the files from Adafruit's website. I uploaded the Trinket M0 file and two of the Max9814, so all of the dimensions and placement was from those files. I'll fix that route when I get a chance. Does allowing a smaller clearance bring any types of problems with it?

Thanks for the reply.

[one-of-the-robs]

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@Anonymous wrote:

Hi,

I got all the files from Adafruit's website.

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Unfortunately not all libraries on websites (particularly those not owned by Autodesk) are properly built or tested. I didn't have time last night to export the library and have a poke around, though if you give us a URL then somebody might.

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@Anonymous wrote:
Does allowing a smaller clearance bring any types of problems with it?

---

As long as you don't reduce the DRC limits beyond what your chosen board fabricator can manage there should be no problems. Your opening post suggests you're intending to use a professional board house but haven't yet selected one. It's worth looking at the web sites of a few likely candidates to see what sort of limits they impose. Some of them even have Eagle DRC rules files you can download.

[Anonymous]

Hi,

Yeah, I plan on using a company to manufacturer the board, if it's cheap enough. Would you happen to have any recommendation on a good manufacturer to use?

Thanks

Patrick

[one-of-the-robs]

Who I use depends on what the board is for and whether I also want them to assemble the components onto it. The latter is the expensive part.

For bare boards of low to moderate complexity, I've had decent results from some of the Chinese ones - PCBWay, Shenzen2U, Elecrow, Smart Prototyping. Have a look at https://pcbshopper.com/ to compare prices and capabilities. There are also reviews on there.

[shubhamdevkar8]

Hello,

I tried with the same one. please check and reply.

I am a beginner.

[Anonymous]

Hi,

The design looks really good! I'll try and incorporate that into mine, but make it a little smaller. Thank you for your help!