How to build my electronic project better

SentinelAeon

Member
Hello,

I regularly make some small projects, mostly for me, sometimes for my friends. They include some simple components, like ESP8266, some step-downs/step-ups, some relays, some voltage led displays, etc. Nothing fancy.

I attached an example of 1 of my projects. Now the problem i am having is, it is really hard to replace a single element if it goes bad. Imagine replacing the little step-down, i would need my equipment if i was to replace it at my friends place.

I am looking for a better way to design and make my little projects. It would be great if all my components, including ESP8266 could be simply swapped with a working part, using the little leg elements (in a similar way that you can replace a fan in a computer, simply unplug it, plug a different one in). Also all those wires are dead weight, it would be a lot easier if i had like a circuit board with all those connection and i would only solver the elements to the appropriate location. But i am wondering how much would a custom circuit board cost - would it make sense, since all other components you see are very cheap (probably everything on the image combined is around 10$.. ) I am just starting with electronic projects and would be really glad for some advices. Visitor Well-Known Member Circuit boards of up 100mm × 100mm can be fabricated by a number of fab houses in China for a cost of$5 for 10 circuit boards. It's very practical to lay out a sort of mother board to plug modules like a NodeMCU, relay board and others into.

You'll need schematic capture/pcb layout software to design a circuit board. JLCPCB.com is one of the good PCB fab houses, and they also offer EasyEDA software to lay out circuit boards. It's a very good and easy program to learn. It makes ordering boards from JLC simple, but can also provide Gerber files so you can have boards made anywhere you want.

rjenkinsgb

Well-Known Member
You could use stripboard (Veroboard) or matrix board as a baseboard, with header pins or sockets soldered in and the link wires between those?

Visitor

Well-Known Member
Here's an example of a "mother board" I designed for a collection of electronic modules. It was for a product development effort to make some prototypes at low cost. The modules were cheaper than the cost of components to build them, and this approach allowed for easy assembly by somebody with limited soldering skills.

SentinelAeon

Member
Thank you for all your replies.

I decided im gonna do this. First, use stripboard that has holes throughout it. This way i can solder pins directly to the board and make my elements "plug and play", so i can swap any element if its broken. Also its easy to solder a few pins neighbouring pins together. I have to decide if i will use wires on the front or back side of the board.

I also checked custom PCBs and i decided i will also use them but only when/if i need to make like 5 or more of the same setup. To only make 1, i dont think its worth the work. Still, might be fun. I remember that in highschool, we did this in 1 of the classes. Sadly, it is many many many years ago so i dont remember much, but it was fun.

SentinelAeon

Member
I figured most things, how to do it. 1 of the things that is still a problem is this small step-down i use in mostly any project. I would like it to be swappable without any soldering or wires. So my plan was to solder pins to step-down, 1 pin to each of the holes (pins fit into the holes nicely, the step down is the size of hand nail). Its easy to separate those pins on the bottom right picture so i get a single pin. But now i also need a female header that will be on the PCB itself. And here is the problem. I cant seem to find a single female header, the lowest i can find is 2 pin. When i look for single female header all i get is female dupont. But thats not what i need. I need exactly what u see on the middle image, but only a single one. That way it will be swappable, but without dupont wires, which tend to get unplugged

Visitor

Well-Known Member
Are you making a pcb "mother board"? If so, I would lay it out for 2 pin female headers, and connect them in parallel or leave the extra pin unconnected. Header pins are square, so you need 2 pins to keep the connector aligned. I'd solder the female 2-pin sections to the mother board, put single pins where they are needed, then position the module on those pins and solder them in place so the alignment is correct.

Visitor

Well-Known Member
A better but slightly more complicated option would be to design the motherboard to fit Mill-Max sockets for round pins, and use headers with round pins on your modules. Then there is no worry about keeping a square pin aligned with a square hole. They have many options for pcb sockets.

SentinelAeon

Member
The middle picture was just an example. I am using headers that have same sides - doesn't matter how you connect them. I am adding another picture to make things clear. As for what i am doing, i included a picture of what im trying to do - but do it smarter, with less wires. Because those wires are just waiting to get unplugged.

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Visitor

Well-Known Member
The picture is and was perfectly clear. As I said, the posts are square. The fit into a socket designed for a square post.

If the pin and socket aren't aligned properly, the socket will not make proper contact with the post.

A pin oriented like this: <>

will not mate properly with a socket oriented thusly: □

Sorry the world won't conform to your vision.

SentinelAeon

Member
Ah, i understand what u mean now. But it wont be hard to align those pins since they have a plastic square on them, im pretty sure i can get that square enough. But good call, will test asap and see if its doable or i will have to go the round pins way

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Visitor

Well-Known Member
The contact in a female header is a thin metal fork as shown in the drawing below. It contacts a square post over a small contact area on opposite sides if the post is inserted squarely. If the post is rotated even a small amount, the already small contact area will be greatly reduced. The result will be an unreliable connection. That's the reason you can't buy a single position male or female header.

Dupont connectors are a different game. There, you have a square (pin or socket) on the end of a flexible wire plugging into a square (socket or pin) header on a circuit board. The pin and socket align because (at least) one of them is free to rotate into proper alignment.

Dr_Doggy

Well-Known Member
lol, i thought it was 100 something, now a days i just google "arduino headers"
also single headers are a bad idea, they slip around way too much
i buy 16 pin strips, then when i need x amount i just cut it down, at the cost of a pin or 2