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huckOhio
(@huckohio)
Eminent Member
Joined: 7 months ago
Posts: 37
2020-02-03 2:50 am  

@robo-pi

I updated the file on the project and it does open.  So now the only thing I need to do is generate the Gerber files?


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huckOhio
(@huckohio)
Eminent Member
Joined: 7 months ago
Posts: 37
2020-02-03 2:59 am  

@codecage

@robo-pi

I updated the gerber and drill files from the latest pcb file.


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Robo Pi
(@robo-pi)
Robotics Engineer Moderator
Joined: 10 months ago
Posts: 1602
2020-02-03 3:04 am  

@huckohio

You're right on top of this!  Good work Mike.  Sounds like you're really anxious to get the board.   I never ordered a board before so I'm not familiar with the process.  But like Steve said, the company will let you know if they don't get all the information they need.  I wish you the best of luck with it. I'll be looking forward to seeing how well it works.  Steve knows more about the ordering process than I do.  He's already had some boards made.

DroneBot Workshop Robotics Engineer
James


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huckOhio
(@huckohio)
Eminent Member
Joined: 7 months ago
Posts: 37
2020-02-03 3:07 am  

@robo-pi

I looked at their website today.  Very straight forward.  I'll see if Steve has any comments on the design and submit to PCBWay tomorrow.  Looking forward to getting the board built and tested.

Thanks again for all your help!

Mike


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codecage
(@codecage)
Member Admin
Joined: 10 months ago
Posts: 517
2020-02-03 11:31 am  

@huckohio

@robo-pi

James, my confusion in the placement of U1 was due to the fact that you said Pin 1 was on the "bottom left" not the bottom right. Bottom left would be Pin 8 to me.

But I do have a couple of other comments:

Why are there two rows of holes on the lower edge of the PCB?  There is only a single row of headers on the MEGA to be plugged into?  The only signals picked up from any of those pins is Reset, 5V, and GND.  And I see one of the two grounds a has trace between the two rows and is not connected, on the shield anyway, to the copper filled zone.  That is not an issue however, just an observation.

And the Gerber files you  created Mike are not exactly the same as those I produced from the ZIP files James provided.  I think I know the answer as to why, but not positive if it makes a difference or not.  The Gerber files I have produced to date were done using the method I got from the "Kicad Like a Pro" book I used to learn how to work with Kicad.  There were some settings on the 'menus' that the author recommended the use of if ordering from PCBWay, that I used and maybe you didn't when you created the Gerber files.  My settings produced two additional files, both of which I wonder are really needed and the file extensions were different, not just "gbr."  I've attached a snapshot of the "Plot" window that shows the check marked files (the F.Paste and B.Paste were my extra two files) and a check mark to "Use Protel filename extensions."  As I said, I'm not positive this really makes a difference, just what I did and I never got questioned by the PCBWay engineers.  Other methods may work as well, I just don't know.

GerbGen

James, I suggested you change the DuPont header that Bill had as J1 since he was now using all JST connectors on the Motor Controller.  But he does have a 6 pin JST at J4 that now goes to his newly designed Motor Controller.  That being said I think J1 is just an additional way to tap onto the I2C bus and is not actually connected to anything else at the moment.  Therefore this could have a DuPont header or a JST connector used at this location.  The builders option so to speak.

That's long enough, in fact too long so I hope I didn't cause anyone to overlook anything.

SteveG


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huckOhio
(@huckohio)
Eminent Member
Joined: 7 months ago
Posts: 37
2020-02-03 1:42 pm  

@codecage

@robo-pi

Steve, thanks for the screen shot used to generate the Gerber files.  I tried to buy the book you mentioned, but it is not available and I don't own a Kindle.  I found a website called OSHPARK that had an example of creating the Gerber files.  I used that example.  I just need to know if you (Steve/James) are making and changes to the connector(s).  Then I'll generate the Gerber files using the setting from the book.

Thanks Steve.

This post was modified 2 months ago by huckOhio

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codecage
(@codecage)
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Posts: 517
2020-02-03 3:19 pm  

@huckohio

I'm not planning on any changes.  While I might have done somethings a little differently than RoboPi did, there doesn't appear to be any real reason to modify his work.

I would like to know the reasoning about the second row of connector holes along the bottom edge (the power and analog pins side) of the board.

SteveG


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Robo Pi
(@robo-pi)
Robotics Engineer Moderator
Joined: 10 months ago
Posts: 1602
2020-02-03 4:38 pm  
Posted by: @codecage

James, my confusion in the placement of U1 was due to the fact that you said Pin 1 was on the "bottom left" not the bottom right. Bottom left would be Pin 8 to me.

Me bad. I didn't realize that I had said bottom left. Yes that would be terrible. ?   I'm not sure if you could even do that in KiCad unless you actually created an upside-down footprint.  But yeah, I meant bottom right.

Posted by: @codecage

Why are there two rows of holes on the lower edge of the PCB?  There is only a single row of headers on the MEGA to be plugged into? 

The reason for the double row on the lower edge of the PCB is so female headers can be soldered onto the top of the board in addition to the male headers that will be soldered onto the bottom of the board.   The only reason I placed that row of headers there is in case someone might want an easy way to access those pins at a future date.   Without those headers if you wanted to access those additional pins you would need to solder wires onto the little nubs sticking up from the bottom pins.  So I just stuck them on there for easy access to those extra pins.

I was thinking of making the board a little more versatile so that it can be used in situations where a person might not be building DB1 verbatim.   This is also why I wanted to add the ESP 8266 WiFi capability.  If someone wanted to they could create a fairly functional robot base just using the mega and a laptop computer, or some other device like a phone or whatever.

In short, I was adding a few features that I personally use on the card without building DB1 verbatim. ?  I figured it wouldn't hurt to toss in the extra capability as those things should not cause any problem with DB1.  Just don't use the extra pins.  You won't even need to solder the female connectors on the board if you don't want to.  But if you want to, the holes will be there.

Posted by: @codecage

And I see one of the two grounds a has trace between the two rows and is not connected, on the shield anyway, to the copper filled zone.  That is not an issue however, just an observation.

Yes, I believe that signal is called GND 3.   It's not connected to the ground plane because I didn't name that net GND.   I could probably do that.  Then it should be connected to the ground plain.  This might also be true for some other GND pins on the mega board.  These are fine details that I agree should be taken care of in the interest of perfection, but from a practical point of view they aren't going to be important for the functions of this board.

Posted by: @codecage

While I might have done somethings a little differently than RoboPi did, there doesn't appear to be any real reason to modify his work.

I could spend time going over this board changing quite a few things myself. ?  This is done actually as a "rough draft".  That's why I'm calling it Rev 0.  Mike seems to be anxious to get something to build. I think this board should be functional.  Could it be improved upon?  Absolutely.  I just blasted this thing out as fast as I dare without getting too soppy.  ? 

Not only would Mike like to get the board built, but I too would like to move on to other projects.  This board doesn't need to be carved in stone.  You can always design Rev 1. ?  And change it up however you like.

I did try my best to make some improvements.  Like replacing the jumpers with a dip switch.  Adding the access headers for the lower row of pins.  Adding the WiFi connector.

Also, Bill may have suggestions for tweaking the actual layout as well for future Revs.   Bill didn't want to commit to an actual PCB at this time. He may even change the design radically before all is said and done.

The bottom line is that PCBs are relatively cheap to order these days.  So Mike can get started with this board, and perhaps send a few to some other people as well.  Then later, if a better Rev comes out, it can easily be unplugged and the new Rev plugged back in.

So it's not like this first version of the board will be carved in stone. I think Mike's idea is to just get the thing up and running without having to build Bill's rats-nest perf-board prototype. ? 

This certainly doesn't need to be the final board for DB1.   This is just Rev 0.   Think of it as a prototype pcb.

And now with the KiCad project I posted anyone can go in and change things up anyway they like.  They can customize the board for their own specific robot.

DroneBot Workshop Robotics Engineer
James


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Robo Pi
(@robo-pi)
Robotics Engineer Moderator
Joined: 10 months ago
Posts: 1602
2020-02-03 4:51 pm  
Posted by: @codecage

And the Gerber files you  created Mike are not exactly the same as those I produced from the ZIP files James provided.

Oh yeah!  There's another thing I forgot to mention.  I noticed that there wasn't any edge cuts included with the original mega shield footprint.   So I drew in some edge cuts around the board.   I forgot to mention that.  That might be in the new pcb file that I posted after having posted the entire KiCad project.   So the Gerber files that Mike produces now should include those edge cuts.  The original files may not include the edge cuts.  I don't remember exactly when I did that.

Hopefully the board manufacturer will tell Mike if anything isn't right and we can then correct that problem.

I'm keeping my fingers crossed at this end, because I never ordered a pcb board before and so I'm hoping this all works out.   At this point I'm just an innocent by-stander. ? 

DroneBot Workshop Robotics Engineer
James


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huckOhio
(@huckohio)
Eminent Member
Joined: 7 months ago
Posts: 37
2020-02-03 6:20 pm  

@robo-pi

Thank James.  I'll generate the new Gerber files with Steve's config setting and upload to PCBWay today.  I did hear back from Bill and he would like a board.  I'll send him one when they com in.  Do either of you want a board?


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Robo Pi
(@robo-pi)
Robotics Engineer Moderator
Joined: 10 months ago
Posts: 1602
2020-02-03 6:43 pm  

Sounds good Mike.  I hope the board turns out okay.  Having worked in R&D most of my life I expect there to be potential problems that will need to be ironed out.  Nothing ever works perfectly first shot.  But with any luck the board will be usable. ? 

There's a lot of signals on that board with all the I2C buses SPI and Interrupts and Motor control.  So hopefully none of these signals will interfere with each other.   I just laid out the tracks to make them fit the board.  I didn't consider how any signals might potentially interact with each other.  But then again, if Bill's homemade rats-nest perf-board works without a problem surely this nice neat pcb should work.

You got me nervous now.  So many people depending on this to work!  I'll find myself in the dungeon of shame if it turns out to have any major flaws. ? 

I'm no expert at designing PCBs.  Although it is fun, I wouldn't mind doing this for a living. ? 

DroneBot Workshop Robotics Engineer
James


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codecage
(@codecage)
Member Admin
Joined: 10 months ago
Posts: 517
2020-02-03 8:05 pm  

@robo-pi

Please don't take my comments as criticism in any way shape or form!  I think you did an amazing job!!

On the second row of holes along the bottom I would have just use female headers with longer pins on the lower half.  That would allow plugging into the MEGA with the lower pins and allow connection on the upper female headers for any expansion.  You would have to be rather careful with your soldering on the protruding pins so as not to interfere with plugging them into the MEGA.  Again, just my way is all and not being critical of your decisions.

And @huckohio I wouldn't mind one if you're not slammed with requests.  Honor them first and if there are any left over, think of me.

This post was modified 2 months ago by codecage

SteveG


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huckOhio
(@huckohio)
Eminent Member
Joined: 7 months ago
Posts: 37
2020-02-03 8:42 pm  

@codecage

@robo-pi

I ordered 5 boards.  I am keeping two (because I figure I'll mess up one) then the remaining three will go to you, James, and Bill.  

Mike


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Robo Pi
(@robo-pi)
Robotics Engineer Moderator
Joined: 10 months ago
Posts: 1602
2020-02-03 9:29 pm  

@codecage

Steve, I'm always open to being educated. ?   If that's the case then there's no need for the second row of holes.  Fortunately I don't think it will hurt anything for them to be there anyway.  I have a Mega prototyping board and they have the female headers offset like this too.

I think this board also has the female headers offset:  I'm not sure why they do it that way, but I was kind of following that practice.

DroneBot Workshop Robotics Engineer
James


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Robo Pi
(@robo-pi)
Robotics Engineer Moderator
Joined: 10 months ago
Posts: 1602
2020-02-03 9:34 pm  

@huckohio

I should  have included your name on the back of the board.  "Inspired by Mike huckOhio"

Oh well, maybe the next board you can put on the back: "Designed by Mike in KiCad". ? 

DroneBot Workshop Robotics Engineer
James


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