What do you use to design a nice looking waterproof device (with LCD+Key)?

Thread Starter

edugimeno

Joined Jan 31, 2019
6
Hi there!

I've been into electronics for the last 25-30 years and recently I am being required to build devices that can last outside (either because they are designed for agriculture or because they are for industrial and need to be soaked in water during plant washing), and they usually need an LCD and sometimes some sort of keyboard/keypad.

Approaches I've taken so far:

1.-Use a transparet lid box like this: https://www.automation24.es/caja-electrica-fibox-tempo-tpc-191209t-5824005
Then attach a rectangular mask inside the transparent lid, apply spray paint where the mask is not covering, glueing the LCD screen from inside right where the mask was, and that's it (no keyboard in this case). This looks FAIRLY decent but takes a lot of time when you need to build a batch of 10-20 and there's always the risk that the mask rises a bit and paint gets underneath, or you don't go 100% parallel, or your screen gets glued a little off the mask, etc.... Not a professional finish

2.-When I needed a small keypad, I used a lcd-touch sensitive keypad: http://www.byvac.com/pichips/index.php/BV4612 This is a cool product that's weather resistant, and you can use your own faceplate with custom designed button icons, but the programming was a pain due to library issues with interrupts, and the front sticker that you design for the button's and LCD frame ends up decaying in just a few months.

I was wondering if anyone knows of a product that includes a waterproof LCD+Keypad in a IP6x box where I can thrwo my electronics inside and end up with a decent looking final product, and allows an easy batch production

Thanks in advance!
 

MrChips

Joined Oct 2, 2009
24,593
I would suggest a custom overlay mounted on a waterproof case.
Underneath the overlay is a Grayhill 4x4 keypad and a 2x16 character LCD.
The case is customized from Hammond.

CTI Monitor.JPG
 

Thread Starter

edugimeno

Joined Jan 31, 2019
6
How do you get that? I mean, do you get those cases manufactured one by one by Hammond? And how do the screen and keypad get assembled so there's no water inside? Any details would be appreciated
I would need a 4x20 LCD thou

Thanks
 

MrChips

Joined Oct 2, 2009
24,593
How do you get that? I mean, do you get those cases manufactured one by one by Hammond? And how do the screen and keypad get assembled so there's no water inside? Any details would be appreciated
I would need a 4x20 LCD thou

Thanks
I took a standard off-the-shelf Hammond waterproof case model 1414PHH4LP.
https://www.hammfg.com/part/1414PHH4LP

Then I created an engineering drawing showing the modification I needed.

1) Rectangular cutout with rounded corners for the display on the front panel.
2) Rectangular cutout with rounded corners for the keyboard on the front panel.
3) Four threaded standoffs spot welded on to the front panel from the inside for the PCB.
4) Circular hole and four threaded screw holes on the bottom for the Amphenol waterproof connector.

Then I contacted Hammond and they provided me with a quotation for 25 cases.

The LCD and keypad is mounted directly on to the PCB. The PCB is mounted flush against the overlay from the inside. The overlay is one continuous sheet of plastic with a transparent window. It was custom printed by another company.

The entire assembly is waterproof.
 

MrSalts

Joined Apr 2, 2020
711
If you use a non-shrinking adhesive, most preferred, a liquid optically clear adhesive, you'll remove the reflections between the display and clear lid (and no worries of night time "ghosting" of characters if your display is back-lit).

also, you can have the graphics printed on the back side of clear polycarbonate film and the film set in the mold at Hammond and "film insert molded". The graphics are between the film and resin and no risk of water damage. Ideally, a polycarbonate box should be hard coated (acrylic spray like modern headlights - not the old sprays that turned hazy after 5 years - or no spray that turns hazy after 1 year).

call Hammond, they can also pad print, print & manually apply decals on the inside of the box, hot-stamp a decorative film into the plastic, all kinds of techniques.
 
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