Complete Electronics Newby wants to Make Circuit Board :0 - Run for cover!

[Ernest George]

Hi Folks!

Not sure if I'm in the right place on the Internet but....I want to make a PCB and am hoping to get some very basic help with this.

The nice thing about this project is that it has several easy 'success points' built into it. Even if I only succeed on the first one, which should be the easiest, then it's all been worthwhile. If I have success with anything after that, it's a bonus! Each successive step is incrementally more involved although, I am sure from your perspective they would all be easy.

The first step should be pretty simple. I want to interface an existing daughter board with 35 pins into the custom circuit board and have it output into an OE-style connector with 33 pins. So really, all I'm doing is taking lines from the 35 pin daughter board and routing them to the proper location on the OE-style connector. Even if I only succeed with that simple step then this has been worth it!

The picture I have in my head is my custom main board, with a 35 pin female connector on it, and 35 (or so) straight lines going to the proper locations on the OE-style connector. In short, 35 (or so) copper traces from the 35 pin connector down to the 33 pin OE-style connector.

Along the way I need to install a simple fuse on the power feed line to protect the daughter board. That's step one. In my mind, this should be really, really simple.

I have some electrical experience. Not much, but I can solder and my needs in this project, even assuming I can get all my optional features installed are not much. I'm certain for you folks they would all be a no-brainer!

I could either make the actual PCB myself in a one-off scenario or have someone make it/them for me.

Anyway, I researched PCB design software briefly and it seems Eagle is the way to go. The thought I had was that I would get a nice screen where I could, for arguments sake, drag 'n drop a 35 pin connector on a board and then create lines going to drilled holes where the OE-style 33 pin connector would go. This doesn't seem to be the case or I'm not doing something right

The reason I'm posting this is to see if anyone is interested in helping me with just the very basics of this thing. I've got an inexpensive hot air re-working station coming (because I needed a soldering iron to replace the $5 finger burner that takes 15 minutes to heat up) and I've printed off a wall sized chart of any schematics that I'm going to need. I am determined to do this thing and as I said, even if I only get as far as making a custom board that the daughter board can connect to and outputs to the proper pins on the OE-style connector, then it's a success.

Any ideas on more/less graphical software that I can use to get started? Or am I taking the wrong approach? I'm kind of guessing that a schematic is not really necessary at this point?

 

[(*steve*)]

It's always worth having a schematic, even if all is shows is pins 1 to 35 of one connector going to 1 to 35 of another connector. You mention a fuse, so presumably there's a little more to it than just point to point wiring.

The first thing to consider is whether the connectors can be mounted on a PCB. If they can't then perhaps you need to look for another approach. Another issue is that connecting pins 1 to 35 of one to the corresponding positions may be trivially easy, or it may require routing wires between pins (or worse, crossing over large numbers of wires).

Once you have the connector, designing the PCB is the easy part. Making it is a little harder, but if it requires drilling, take it from me that it's non trivial to drill 35 holes accurately spaced so the connector will fit into it. Large holes make fitting it easier, but make soldering it harder.

Perhaps if you can post some images of the connectors showing the mounting pins, we can give you some more hints.

Eagle is certainly an option. And if you go for a third party making the board you trade time and cost against a better quality product (that won't have problems with inaccurate drilling for example).

 

[Ernest George]

What an awesome reply- thank you Steve, much appreciated.

From your post (one that's based on experience) it's clear that I am going to have to have a schematic. I mentioned earlier doing the board in stages so first stage is point to point with a in-line fuse on the 12v power feed. Second stage would be sending some lines to a separate connector (should also be easy), third stage would be adding a bluetooth module, and there are two more stages so it will increase in complexity as I go along. However, like I said, I would be happy even if all I could do was point to point. Everything else is a bonus so I've set my goals in a progressive manner due to my complete lack of experience.

I'm not re-inventing the wheel so the connectors can certainly be mounted to the PCB - that's no issue. However, you raised some really good points about drilling holes and the like. I can see that it would be way smarter (and cleaner) to have an on-line company make the prototype boards as I will never be able to get it that clean. This leads me to the thought that accurate design with respect to the holes (and their spacing) is going to key as well as the layout to fit in the enclosure I want to use. This may end up being a case of the idea is easy, the implemenation - not so much

The attached picture is representative of the board I am planning on making (the green board). The external connector will be different (I have some engineering samples coming). I love the look of this guys work - that's really what I'm trying to replicate.