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I've decided to use Sparkfun's Pro Mini boards to make my project into a semi-professional product.

My first thought turned to enclosures - of which the entire internet seems to be bereft. If I ever DO see an enclosure, it's for the Uno sized board and costs about twice the price of the board, which seems incredible to me.

No matter, I have found a way to make quite good enclosures for the Pro Mini pretty easily and cheaply.

HOWEVER, the next problem is mounting the board inside the box. I would like to be able to mount it firmly to the base but in a way which allows it to be removed if necessary. Obviously, there's not a lot of scope for putting screws through the board. It occurs to me that anything which holds it would need to do so by gripping the edges or the corners. Is there such a thing?

If there's nothing that fits the bill, would the board be OK if I were to HOT GLUE it to the base of the enclosure?

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    What about using the pins to secure it? If you want to make it look "professional", just make a custom daughter board with the connections, make it so that you can firmly attach it (screws, plastic tabs, hot glue or even just rubber and a well-sized enclosure), then use the two pins rows to join them, so that you can unmount it easily
    – frarugi87
    Mar 9 '16 at 9:48
  • What do you mean by "The Pins"? The pro mini doesn't have any pins, just connection "holes", is that what you mean?
    – Lefty
    Mar 9 '16 at 10:01
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    Ok, then one more step should be added (forgive me, I thought it was obvious): you should solder the pins to the pro mini like this image (of course without the serial connector - the six pins 90-degrees connector on the top layer)
    – frarugi87
    Mar 9 '16 at 10:06
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    @frarugi87 It probably WAS obvious to most people but not to me unfortunately. I'm not intending to use pins for the electrical connection - was just going to solder wires direct to the board as needed. However, I like the idea of using a few of the pins as "legs", I will explore that option if no-one offers anything better as an answer. Thanks for your help.
    – Lefty
    Mar 9 '16 at 10:56
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    that's why I wrote it ;) and the comment was not sarcastic: I really meant "forgive me", because I really though it was and I understand it wasn't.. Anyway I suggest you to avoid soldering them directly on the board (this will limit your replacing easiness), but instead solder them on the base and then use just the pins for connection. If you want to avoid an extra board, you can use a perfboard or even just two female headers glued on the case and with the wires soldered to it.
    – frarugi87
    Mar 9 '16 at 11:04
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What type of box? Howmany times/how easily do you want to remove the Arduino Mini?

Hot glue

Hot glue is the way to go in many occasions.

  • It does not conduct electricity, so is pretty safe. (Please check your specific hot glue first)
  • It sticks quite well, for quite a time. You should also check if it's water resistant or fit for your target environment though.

But, it may have some side-effects:

  • It can get quite messy (which does not look really professional)
  • It's not that easily removable and has to be "re-glued" when you want to stick it back.
  • It might be too sticky (in a carboard box, you won't be able to just rip out the Arduino, withouth damaging the box).

You could use double sided tape, which might actually work fine. Or atleast better/neater as the hot glue.

Sticky velcro

A neat solution would be sticky velcro. You can easily attach, detach and re-attach the arduino to the velcro. It looks quite fancy and should hold well.

Again, you should check the specific velcro, it might not last 1000+ times of re-attaching (become loose or smh). But will be a good option overall.

sticky velcro

Extra

You can use mint-boxes as an enclosure. But they're usually made of tin or another conductive material. Please take care and cover the back of your arduino (or box) with electrical tape, to avoid shorts.

Extra-extra, you should (for "replacability") add connectors or headers to your Arduino. Since soldering the leads directly will still give the need to un-solder or resolder your Arduino when replacing.

Note on making your Arduino project a consumer item

You might save yourself quite some money by using a barebones arduino. Or actually, an ATmega 328P chip. Which is around 3€. These will be a little more difficult to program, but might also look more professional.

You can also enable "program protection" fuse bits, so that others can't download the code from your arduino/microcontroller.

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  • Excellent answer, thank you @paul. I don't really intend to keep removing the Arduino from the box, but I'm sure I will need to, especially on the first ones. I like the idea of the sticky velcro - I actually have some of that in house already so will give it a try. The box is going to be made from plastic and I can easily make them exactly the size I need. The Pro Minis work-out to around the £2/3 euro cost too, so I'm not that concerned, especially if it's going to be harder to program - BUT, I am interested in keeping my code secret though so will investigate.
    – Lefty
    Mar 9 '16 at 14:22
  • @Lefty, Pro Mini's are 10€ at more "official" shops. But indeed, for €3,- it's not really worth it. You could however use barebones arduino's to fit in even smaller enclosures or, on your very own PCB (if you need other circuitry). Programming should actually be the same as in the pro mini (IF you have a bootloader installed in your barebones implementation.). (Basic) code protection involves disabling the "Fuse bits" for SPI download. Keywords to search will be: "flash protect, code download disable, fuse bits" etc.
    – Paul
    Mar 9 '16 at 15:18
  • thanks again. I will investigate the barebones option, purely because of the code-protection aspect, but size-wise, the Pro mini is well within the maximum size I can tolerate. I don't need any extra components and haven't made a PCB since I was at school - 40 years ago! So the pro-mini is ideal except for the code protection aspect. I paid £3.75 for the one I have bought so far, but the price drops significantly if I get 5, 10, or 20 at a time. Amazingly, it's about the cheapest part of the project.
    – Lefty
    Mar 9 '16 at 16:05
  • @lefty the pro mini isn't that much different from a barebones arduino. If you have an icsp programmerer. You can actually enable read protection on a pro mini. But it won't work through serial-usb programming. By using an icsp programmerer, you don't even need the bootloader, thus have more program memory and others can't just upload arduino sketches through serial. Which might be usefull
    – Paul
    Mar 9 '16 at 17:24
  • More interesting stuff! I don't know about "ICSP" but I have an FTDI(?) programmer that I realised I needed for the Pro Mini. I used it successfully with the IDE. Looks like I have some more searching to do....
    – Lefty
    Mar 9 '16 at 17:36

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