I'm building a small electronic device that will be installed outdoors, and I'd like to weatherproof the only button that it has. I've attached the part's datasheet as a reference.

Among other considerations, I've been thinking about using an o-ring squeezed between the button and the plastic lid as shown below.

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To be honest, I'm not convinced this is the best way to go around it. Question, is there a better way to accomplish what I want? ... I'd like arrangement to comply with an IP66 rating, if possible. Also, I'm willing to use different hardware if it solves the problem in a simple way. The only condition being that said hardware must be mechanical, and not of the capacitive-touch type, for instance.

 

How about a waterproof switch made for the purpose?

 

Do you want to weatherproof the switch itself, or the hole it protrudes through? The latter is harder because you want a controlled friction against the stem that is water-tight and does not degrade with time and use.

I was going to suggest a pre-made waterproof switch with wires going to your pc board if you have room, but Jon beat me to it.

ak

 

Thanks both Jon and Kid for your involvement. But I'm looking for a small push button of similar (or smaller) dimensions than the one I originally posted. A 12mm button is humongous for my needs! ... so it's out of the question.

Do you want to weatherproof the switch itself, or the hole it protrudes through? The latter is harder because you want a controlled friction against the stem that is water-tight and does not degrade with time and use.

I was going to suggest a pre-made waterproof switch with wires going to your pc board if you have room, but Jon beat me to it.

ak

Either one would be fine, as long as water (or moisture) does not creep through the arrangement.

I've been doing some digging, and the problem I'm describing seems to be a common issue among hobbyists. It seems that I'm going to have to get creative on this one.

 

https://www.amazon.com.mx/UNIT-ELECTRONICS-Button-Membrana-Botón/dp/B0GPDRXSNH

 

How about a 10 mil mylar "dome" fastened over the push button, attached to the enclosure surface with a ring of good 3M pressure sensitive adhesive tape.

You might be able to create a custom die to form the dome into flat mylar sheet with some household materials.

If the dome falls off in use, you're out of luck.

BTW, I've done this for production in the past, but the mylar was a full printed label with domes embossed into it.

This is similar to the construction of a tactile keypad with, well, embossed domes on the top layer.

 

Also, you can buy metal domes which lie on a corresponding pattern on the PCB, then use rubber buttons (like an old cell phone) which protrude from the enclosure for actuation. The rubber button "rim" seals against the inside surface of the enclosure.

These give a real nice "click" tactile feedback.

This requires accurate dimensioning of the enclosure, though, to work properly, along with alignment features.

 

If this is a design for production, the simplest approach is just have a tactile keypad produced for you, and attach it to your PCB with the appropriate FFC/FPC connector.

 

I have made membrane buttons with those domes. I simple tape “scotch tape” over the domes.

 

I have made membrane buttons with those domes. I simple tape “scotch tape” over the domes.

Yup! Quick and dirty prototyping.

 

Yup! Quick and dirty prototyping.

The scotch tape does not last forever. Use a more durable thin sheet of plastic material.

 

I have made membrane buttons with those domes. I simple tape “scotch tape” over the domes.

That's how the original TI 4 function calculator with the LED numeric display was built.

 

If this is a design for production, the simplest approach is just have a tactile keypad produced for you, and attach it to your PCB with the appropriate FFC/FPC connector.

At this point, I'm thinking that's going to be the safest bet ...

 

At this point, I'm thinking that's going to be the safest bet ...

Do you need help? I can give you a reference design.

 

Do you need help? I can give you a reference design.

That'd be real nice, thanks ... feel free to PM me if you want to keep your design private

 

That'd be real nice, thanks ... feel free to PM me if you want to keep your design private

It won't be till next week. Going to Rockville this weekend.

 

It won't be till next week. Going to Rockville this weekend.

Nice! ... open a thread or something and tell us about how things go

 

Nice! ... open a thread or something and tell us about how things go

I hope we get lucky. The entire day today was shut down on account of extreme weather.

 

Magnetic reed switch.

 

Magnetic reed switch.

The problem is the required magnetic button travel, and integration of the button (and spring) into the enclosure.

Edit: and no tactile feedback.