Here it is. If you have a project that needs keypad input and LCD screen, this tutorial is for you.
I will make a video later with projects using this setup.
Looks nice - I would suggest
- Cut the hole larger to fit the bezel, and/or...
- Use (or make) "studs" for the LCD that can be epoxied to the inside of the case (so no visible screwheads)
- Alternatively, make or thread ABS (or whatever material the box is made of) studs, then glue them with the appropriate glue
To make the studs, you could simple use some flat-head screws or similar. Another way might be to cut the head off the screw, then thread a nut in place. You might also try gluing a nut in place, then thread the screw into that (if there are enough threads to "catch"). Finally, you could glue/epoxy in place some abs or nylon standoffs, then screw the LCD in place (you might tap the standoffs beforehand).
I just think that if you can hide the LCD mounting screws, it would make the project that much better; as it is, it looks great - take it to the next level next time around.
On another note: Too bad that keypad didn't have E and F keys; it could make a sweet hex programmer (or other similar "terminal" handheld)...!
Thanks cr0sh. I'm using smaller screws now I am hoping to spray the screw heads with black spray paint to match the color. I could use hot glue but it won't be as strong as 4 screws and I can't get it off any more. It's a serial LCD backpack so I play to reuse it if I have to, in future projects. I'm making a handheld clock at the moment, just something to show off the enclosure.
Thought about a bezel maybe this:
But ouch 4 bucks. I can buy a keypad with that money.
I've used a number of the bezels you point out. They saved me a ton of work getting the perfect hole in an enclosure to see the lcd through. Yes, they cost some, but they saved me hours of filing, sanding, and fitting the displays. I support my boards with hot glued plastic threaded standoffs. They cost almost nothing when you buy a bag of them off ebay. I also use nylon screws to hold things in place; they work fine until you drop the device and then the head pops off the screw. But, being nylon, they don't short anything out and I don't have to worry about them cutting the traces on anything.
To cut the hole in a plastic enclosure, I put a rotozip bit into the dremel; it's 1/8th inch and fits fine. Then I can plunge the bit through the plastic and use the side of the bit to cut out the rough opening. To smooth it, just put one of the round sanding bits in and rough sand the big jagged edges. Like I said, I make the hole to fit the bezel and then mount the lcd behind that with glued in standoffs. For something that needs to be a little more rugged, I have used epoxy putty to hold the standoffs. Get the epoxy putty for plumbing; it sets up in about 15 minutes and you can sand it in around an hour. So you shape the stuff, cram it into one end of the standoff so it engages the inside threads and then mash it onto the plastic enclosure. Fifteen minutes later you can test fit the lcd. After an hour you can use the dremel to fine tune the shape of the epoxy.
The beauty of using plastic standoffs and screws is that you can buy the one inch long ones and cut them down to fit whatever you need. That way a bag of them can last through many projects.
If you happen to be using a metal front panel, the bezels can really save you time and frustration. Just use a hand nibbler to cut the rough opening to hold the bezel and then glue it in place. This saves several hours of messing around trying to get it just right.
Thanks draythomp. I will get a few of those bezels next time I order from digikey. I can certainly get a few more bits for my dremel. The darn thing has so many accessories and I don't know enough which does what job. So rotozip it is then. I also messed up the case a bit since my key-less chuck is fat and grinds on the case while I was cutting with abrasive disk (oops). Something I can avoid with a cutter. I can really use some workshop space and a drill press for the dremel.
draythomp and co0sh, since this project was to show how to make a user interface, can I copy your responses to my blog as comments?
For my own complete products, I would try my best to leave space on my PCB so the LCD can be soldered on the PCB and the PCB mounted to the standoffs inside a box so all I need to do is to cut a hole and use bezel. That saves time from securing the LCD, which a one-off project always needs to deal with.
I once opened up a similar commercial product and the front panel has membrane key and a connector in the back to plug in the PCB, which has standoffs to prop the LCD up to reach the window. I'm going to do that. With a bezel, I bet I can put a window in for dust.
Is this the right rotozip bit?
http://www.sears.com/shc/s/p_10153_12605_SP101A9692S5323627201P?prdNo=15&blockNo=15&blockType=G15
Or is this the one?
http://www.sears.com/shc/s/p_10153_12605_SP101A12637S4045378101P?prdNo=1&blockNo=1&blockType=G1
You can certainly copy my comments from here to there. Also, the bezels I get have a cool little window in them already. It's some kind of slightly tinted plastic that helps with the contrast and looks real nice. It keep the dust out and I don't have to worry about taking it apart to clean inside. The actual part I ordered is PRD250LPW-ND, but there are slightly different sizes and such that are very similar.
I love those bezels. They ain't cheap, but they have saved me a ton of frustration. If you want to see what they look like finished, just check out most of my projects posted at desert-home.com (link in signature).
The single disadvantage I've found is that, since there is a layer of plastic next to a layer of plastic, cleanliness in assembly is important. You can get a little dust or piece of plastic between the lcd and the plastic screen in the bezel and it looks like you haven't dusted in years. Just make sure they are both clean when you put them together the final time.
Regarding rotozip bits: the most expensive one (naturally) http://www.sears.com/shc/s/p_10153_12605_SP101A12637S4045378101P?prdNo=1&blockNo=1&blockType=G1 . But the main thing is the number of turns in the cutting surface. A small number of turns means it cuts faster, but is harder to control and can get away from you and gouge out the edge. A large number of turns means it goes really slowly, but you don't have nearly the problem with control. What I did was go to a store and look at the different kinds and picked one that I thought I could control. It worked great. Using these things on plastic doesn't stress them at all, so a bit will last a couple of lifetimes, or til you lose it; whichever comes first.
Oh, one other thing. When using glue or epoxy to hold the standoffs, rough up the plastic enclosure a little bit with some sandpaper. This removes the shiny surface and makes some little sharp ledges for the glue to stick to. It make the standoffs much more secure.
And, above all, have fun.
Hey thanks a lot. I wish sears carries enough dremel stuff compared with their own brand. The item in the link is not sold directly at sears. Will check home depot. I just looked at your blog. Nice projects! The sneak looks real by the house controller. Just what is the animal that was making the noise in the back ground? 
Maybe you can use different serial LCDs in one of your projects, instead of the sparkfun one, which is really wide. Check out my signature. I have some serial LCDs too!
The noise in the background is an African Gray parrot. Noisy little sucker. And, I'll never, ever buy one of those sparkfun lcd displays again. I finally found a place to use the ones I bought originally, and when they fail, they'll get replaced with something more reasonable. Whoever the engineer was that worked on them should be slapped on the wrists.
draythomp:
The noise in the background is an African Gray parrot. Noisy little sucker. And, I'll never, ever buy one of those sparkfun lcd displays again. I finally found a place to use the ones I bought originally, and when they fail, they'll get replaced with something more reasonable. Whoever the engineer was that worked on them should be slapped on the wrists.
Well, in case you really hate it so much and don't mind a trade, I can send you my assembled serial LCD for the SerLCD. Mine also supports direct connection with the 4*4 membrane keypad pictured above. I've always wanted a SerLCD just to see how disappointing it is, at the price it is at and the amount of firmware function it offers. 
That's a great offer, thank you. The problem is that I have already modified the enclosure of the ones I have and have them mounted in working devices. It would be too big a pain in the butt to take them apart and readjust everything to support a new LCD when they aren't broken. If I do have a reason to get into them at that level, I'll just send one to you. I won't go to the trouble of replacing it with the same king of thing; that would be to dumb...even for me.
No problem here copying my comments, either...
Here is how it looks like in a rubber protective case, like a real deal
