Main Site Documentation

I need help to design a shield


#1

Hello,

since my Domino is dead, I have to do something else while waiting for replacement… ::slight_smile:

I have a project where I need a Moxa Serial-to-Ethernet board. This board fits on an Arduino shield but any existing proto-shield I’ve seen are not designed for this. So I wanted to create a new shield from scratch.

But… I don’t know how to use Eagle to do this. That’s why I ask for help here. I hope that I’m not in the wrong place ?

Here are the documents I have :

Before going further, I would like to know if someone would like to help me with this ?


#2

Where exactly do you need help?


#3

I need help in designing the PCB layout (2 layers max) and get the necessary files for making a custom PCB.

I already have the ideas about connections and components I want, but as I don’t know how to use a program like Eagle, I’m stuck.


#4

To give a better idea, it would look like this.

The blue wire is here because the RJ45 breakout has a defect on one pin :frowning:


#5

What I mean is that you are need someone to make the eagle file for you, not help you learn eagle, right?

This is where you could use the GHI consulting hours if you had higher ranking on the forum :smiley:

I would help you anyway but I am just too busy now


#6

Right !

GHI consulting hours are for commercial projects. At this moment, I don’t know if this one will ever become commercial or not.

Maker Faire is taking a lot of time, maybe ?


#7

If I were to do the same thing, I would go to these tutorials first (I did it this way too)
It probably take you a few days to go through 11 tutorials on how to use eagle until you send your design out and get it back.

http://www.sparkfun.com/commerce/tutorials.php

Why don’t you try to use blank proto board that fit on Arduino first?

Moxa Serial-to-Internet Breakout Board is only 57x40mm and it will be fit nicely on this

http://www.adafruit.com/index.phpmain_page=product_info&cPath=17_21&products_id=187
and have some room to add other components onto the board.

These are also of blank proto board.

http://www.adafruit.com/index.php?main_page=product_info&cPath=17_21&products_id=55

http://www.sparkfun.com/commerce/product_info.php?products_id=7914

To do a project like this I’m not going to jump into Eagle right away you need to test your board first before step into do the shield with eagle.
You need to know each component to use in your shield and need to make sure that each components won’t fail you.

I hope this is the answer you are looking for.


#8

Bec, is there any reason you ‘have’ to use the serial<->enet board you listed? To me it would seem to be easier to use the WizNet board that GHI provides direct support for.


#9

@ Jeff : there are many reasons for me to use this board :

  • I got it before the Wiznet driver was completely usable
  • I have it and I don’t have the WizNet board :wink:
  • most important feature, for me : the Moxa board can act as a virtual COM port for Windows, a feature very useful for almost all the programs I’m currently using.
  • it can use using only 2 pins for serial communication (Domino <-> Moxa)
  • not really important but still : it also exposes 4 programmables IOs. That saves 4 on the Domino, for example.
  • less important, it already has some little “plus” like email alerts on different conditions

@ Sam : in fact, I don’t have “time” to learn something almost new for me :frowning: Altough some years ago, I have used Proteus PCB Design for a small board (see below). But I don’t have access to this program anymore, hence my request about Eagle.

The proto boards you mention don’t really fit my needs because they have many “features” that I don’t need like rails or SOIC. This take some useful space. Also, Moxa pinout is not really suitable for use with this kind of breadboard.
That’s why I think that a custom PCB would be better : only the components I really need and components specifical to this module (IOs, for example).

Waht do you mean when you say ? [quote]you need to test your board first before step into do the shield with eagle.[/quote]

Anyway, I thank you for your answers.

Oh, I still have a question : how much current can the 5V pin on the Domino draw ? The Moxa is using 300mA in idle state and is said to go to 900mA on load (though I haven’t seen this high value yet :think: )
This would change the way I power the board, of course.

Here are some pictures of a board I’ve made with Proteus PCB Design :

And the final real board :


#10

Eagle has a steep jump for a learning curve and then it’s pretty gentle. Download the sparkfun parts library as it has almost everything you’ll ever need in it. Start with your schematic, follow the sparkfun tutorial it’s pretty good. Then layout your PCB. I like to bring in the dimensions layer to the size of the board i want and then add things which must be in a certain location (headers for instance). From there, its just a matter of laying out your components so that you can route it (make sure you change the parameters on this) and check the ratsnest tool to make sure there are no airwires.

There are a lot of tutorials on eagle around the net :slight_smile:


#11

Ok. Thank you all for your comments.


#12

After some trial, here’s what I can get. What do you think ?

Board is not complete yet, as I have to add some connectors and components, but I have a question, though : how can I restrict routes to the bottom copper layer only ? :think:


#13

Sweet! You learned EAGLE in 1 day :slight_smile:

You only have few traces so why not run them manually. GHI never uses the autorouter. Nothing beats the art of human eyes.


#14

Change to ‘Cost’ of the top layer to 99. You can also just change the layer on all the top routes to move them to the bottom. As simple as that board is you could very easily make it a single layer.


#15

I’ve changed “Preferred direction” to N/A for the top layer and it almost works !
I say “almost”, because I’ve added a SMD reset switch ::slight_smile: Guess what …


#16

I will try to learn eagle later today too. Always nice to create some stuff ;D


#17

Have any of you any experience with DipTrace?
http://www.diptrace.com/index.php
It looks impressive and the 300 pin free version would probably cover most of my needs.
Tip: if you become a member of LMR you can get 250 extra pins for free; http://letsmakerobots.com/node/6396


#18

I don’t want to learn a 3rd program :naughty:

:smiley:

I might try it, though I think it may miss some components. I have to admit that the Sparkfun lib for Eagle is very useful, along with many (many) other libs available here and there :o


#19

Here is the latest version.

I’ve restarted from scratch, but this time using FEZ Domino schematics & board as a starting point. Since I’m in this forum and asked for help here, I think it’s fair to use them instead of others.
That’s why I’ve kept some GHI’s text on the board. Please let me know if you’re ok or not for this text.

Anyway, apart from the Reset button, all is now on the bottom layer. I had to tweak a little bit by adding some headers so that traces don’t overlap, which would result in top layer traces… But those header could be useful, so it’s not really cheating :wink:

Also, I’ve made a Moxa4100 device/package. It’s the first component in my library :stuck_out_tongue:
For the other componets, I’ve used the Sparkfun lib.

What do you think of this one ? Is there something wrong or that I should have done differently ?


#20

Just in case someone is interested, here’s the latest version.

I’ve change the RJ45 connector for a MagJack with internal leds and used another push-button for reset. This saves me many traces and thus permits to use only the bottom layer.

I’ve also tweaked some parameters for the autorouter to help using space more efficiently (at least I think so).

Also, since I didn’t get any answer about the FEZ texts on the board, I will assume that it’s okay to leave them.