-->
Page 2 of 3

Re: PC board fabrication

PostPosted: Thu Nov 01, 2018 6:34 pm
by rudy
https://easyeda.com/

I would try that if you are going to use JLC-PCB. They have a link to it on their website. My thought is that you may have one less issue as far as board files and formats. I expect they know what to expect from the output of that program.

A part of my job at work is to do the pcb layout for my designs. I have used Pads for over thirty years now. It is a commercial package and hate how much we have to pay for it. I think it was about $5000 for the basic level with one license.

I have a few boards I want to do. I wanted to use a free package but I just hated to have to learn a new program for the little I plan on doing. So I had borrowed the USB dongle a few times but haven't got too far due to lack of time.

Assuming you pick up the program's operation pretty fast, the part that can suck a lot of time is making parts. Parts for the schematic, and then the footprint for the pcb layout. Whatever package you look at, take a look to see if there are libraries for parts you plan to use. Look to see if they have the ESP module you want to use. Odds are you probably will use pretty standard parts. When using someone's library part, check it over carefully. Make sure the dimensions are correct, the pads and traces how you would want them.

Most surface mount footprints are made as small as the part allows. This is great in order to get higher part density in the design but it doesn't make it easy for manual assembly or rework. I tend to make my pads extend further beyond the part in order to give me some pad that I can touch a soldering iron to when I am soldering the part.

I suggest staying away from autorouting a board. It usually eds up being crappy. Auto-routers are ok if you put enough effort into working with the rule set. And that often is as much work as just running the traces yourself.

One of the worst things as far as pcb design is the ground symbol. It gives the allusion that as long as you are connected to the ground net, that everything is ok. When you have an input or output, follow the path that the current will need to take. The whole path from whatever starting point you have, along with the return path back to the start. It should be as direct as possible. Not snaking all over the place. Usually I look at ranging the parts so the connected parts fit together as cleanly as possible. But when I start laying down traces I first start with power and ground. I might or might not not run them completely, but I plan the path and how it will end up.

Re: PC board fabrication

PostPosted: Fri Nov 02, 2018 11:28 am
by ian
I use jlcpcb a lot. Their boards are great! Prices too.
I use Diptrace for designing boards at home. There is a free version for 'small' boards.
I tend to miss out the schematic capture & go straight to the layout. Nowadays most of my designs use 'modules' rather than discrete components & I'm too lazy to create things for libraries.

The auto router in Diptrace is very good. I take Rudy's point - it does some stupid things from time to time, but as well as being lazy I'm also impatient!

You can see a design of mine at http://www.myiot.co.uk/wemos/
This was designed for a student lab. Created in Diptrace & PCBs produced by jlcpcb.

CAD software is a very personal thing. You will often see Eagle recommended. Some of my friends like Eagle but I hate it!

Ian

Re: PC board fabrication

PostPosted: Mon Nov 05, 2018 10:03 am
by Tom Park
Thanks for taking the time to provide such useful info. I looked at easyeda, and it looks like it'll provide the functionality I need without a steep learning curve, and it has the nodeMCU module in the library which simplifies the process. Nothing I want to make is complex, and in fact I think I can design a single board that could be used for several applications depending on how it's populated.
One thing for sure...with all these cheap and powerful parts it's really fun being a retired engineer these days.
Tom

Re: PC board fabrication

PostPosted: Thu Nov 15, 2018 7:06 pm
by Tom Park
For anyone interested in this topic, I used the easyeda.com site to first draw the schematic, and then design the PC board. Admittedly what I wanted was very simple...nodeMCU, relay, and a few discrete components, but the process was VERY simple. All of the components were contained in existing libraries, so that made it even simpler.

Once the schematic was finished, I switched to the PC board layout mode, placed the components, ran the traces where the lines indicated they should be, added input and output headers, text to identify things, and mounting holes. Once I was satisfied with the layout, I created the Gerber files which just required clicking on a menu item. Then I clicked on the JLCPCB icon and was taken to their site where I dragged the Gerber zip file to it, answered a few questions mostly accepting default answers, and placed the order.

The board is roughly 2.5"x 2.25", and the cost for 10 is $2.00...not each, total. I opted for DHL shipping for $17. So 10 boards including shipping is $19.00.

JLCPCB says 2 days for the boards, then whatever time DHL takes, so I'll probably have them in a couple of weeks.

If I screwed anything up and wasted $19 I'll report that so others can avoid the same mistakes.
Tom