ISO cheap outdoor keypad for access control - Page 1
Forum section: electronics / general

author: soldar
author_rank: Super Contributor
timestamp: January 03, 2019, 10:10:12 pm
content: I have a load of access control circuits but they need a keypad. If I found cheap weatherproof keypads I could sell some of these things or even use them myself. But every time I look there is really no cheap keypads out there. What I am looking for generally:- Basic keypad with, say 10 ~ 12 keys. Could be more or less.- 1/n config (not row/column)- Reasonably weatherproof.- Low costThe electronic circuit requires four keys to be pressed in the correct order and then activates a relay. It is not high security but reasonable for something like an outside gate.If I could find a cheap keypad I could offer some for sale but nobody is going to buy it without the keypad.For my own use I have thought of making a keypad myself but even individual weatherproof push-button switches seem pretty expensive. It seems anything mechanical is inordinately expensive.Any ideas?

author: Halcyon
author_rank: Unknown
timestamp: January 04, 2019, 02:26:21 am
content: Big Clive did a video on a cheap RFID/Keypad. I'm not sure if something like this would suit your application?

author: cdev
author_rank: Super Contributor
timestamp: January 04, 2019, 02:31:01 am
content: How about using Asterisk and a durable but cheap VOIP phone in its own walled garden. (set up so its not able to call out) disencapsulated from its cheap case and built into a better, ruggedized case?Or use an RPI clone and touch screen display with a screen keyboard to do that.That seems like it might be fairly straightforward.

author: soldar
author_rank: Super Contributor
timestamp: January 04, 2019, 09:29:07 am
content: Um, thanks but I am just looking for a cheap, outdoor keypad with a few push-button switches. I could not imagine it would be so difficult to find.I even thought of making my own but most push button switches are not well suited for outdoors. I seem to remember there were push button switches that had a reed switch and a movable magnet.I suppose in these days of RFID anything mechanical is out of the question.

author: cdev
author_rank: Super Contributor
timestamp: January 04, 2019, 03:35:57 pm
content: You can buy a complete RFID access control kit on ebay or the other auction sites- with a bunch of individually coded keychain dongles to give users- for very little. ($10-15) If you can live with your users getting RFID keychain dongles instead of a keyboard that would work for you that would likely work well. You can also get them with cards. They also come with the sensor, etc. and windows software for managing users. That way if you lose one of the cards its easy to deactivate that card. Also you can track usage, so tell when employees arrive and leave a work site, etc. If you go this route I would scan Github first to see if any have a compatible project and code you can use. Save yourself some work.As far as keyboards, you could use a cheap membrane switch, I have some 3x5 matrix switches (They were bought at Radio Shack a very long time ago, so I dont know the manufacturer but their RS SKU was 270-215) which use little metal bubbles for the contacts. They came with a plastic box as well, with a cutout and were not waterproof but I imagine they could easily be waterproofed by not using the case, instead building your own case and putting the keyboard behind a thickish, flexible piece of plastic.It likely would look cheap unless you did a really good job on the design, nullifying the inherent cheapness of the membrane switch - They tend to hold up for at least a couple of years, (but do wear out under heavy use, fairly soon)However assuming you find one you like and it doesn't vanish from the marketplace, they are cheap enough to be easily replaceable.You could use a Blue Pill or something for the board, and use a LCD display or a cheap TFT display to issue instructions to the user "please enter in your access code now" etc.The economics of the Arduino shield/Raspberry Pi Hat ecosystem, however, makes me think you might find that you could get a better end product for not much more money using the widely sold touch screen displays etc. for them.I'm not thinking of using Raspberry Pis, one of the lookalike boards that have ethernet and a compatible footprint that leave out the graphics acceleration and run Linux would be cheaper. For access control I would definitely use wired Ethernet, not wireless.Some of them are as little as $10-15

author: soldar
author_rank: Super Contributor
timestamp: January 04, 2019, 05:18:49 pm
content: Thankscdevbut I am looking for something much simpler and much cheaper ... and by the looks of it very non existingI have a stock of very simple access control circuits and am looking for any possibility of putting them to some use. I know I can buy complete systems but, again, I am looking for a very low cost keypad which would allow me to put the stock I have to some use.My experience is that outdoor weather is very harsh and soon the sun, rain, dust, etc, take their toll.I am beginning to get involved more in things mechanical and have thought maybe I could build some keypads by using some weatherproof push button switches but even those are not cheap or easy to find.Maybe I could use regular push-button switches enclosed hermetically and with a membrane which allowed pushing them. In other words, the outside, visible button just pushes a membrane and behind is the real switch.Another possibility is to use reed switches but, again, not simple.Anything made of plastic should probably be protected from the elements by a box with a cover which is only opened when the user is going to use the keys.Part of the problem is finding switches with numbered keycaps.It just seems strange to me that this is not something easily commercially available because I think there would have been a need.I guess I could use keypads recycled from old phones but I don't think they would stand well to the weather.As I dedicate more time to machining I might attempt making something myself but engraving the key caps remains a problem. Probably not an efficient use of my time either. Oh well. The stock of circuits I have will probably end up in the junk.

author: cdev
author_rank: Super Contributor
timestamp: January 04, 2019, 06:40:28 pm
content: This is unlikely to apply to your hardware, its just a comment on the idea of using old phone keypads and HW.I used to know people who lived over a period of many years in a big old shared household in Berkeley (mostly CS and engineering students) and over a time period of maybe one and a half decades at their door they had a progression of differently similarly themed phone-based front door intercoms built from old phones and PBX/key systems.They all used very old phone equipment, (most of which was built like a tank) and you know, it seems to me that they held up pretty well. Some of them were really old, lovingly restored to beautiful condition.Berkeley - especially the lowland part is in a Mediterranean climate that is fairly dry, if where you live is like that, (I don't know where in Spain you live, some parts are exactly like that microclimate in California, other parts maybe more like other parts..)Anyway, just a data point.If its dry most of the year where you are, and doesnt freeze, old phone equipment keypads would probably work okay if you shield them from direct rainfall underneath some kind of overhang.At least here in the US all that old phone equipment are built to last almost forever. They really don't make hardware like that very often any more.

author: rhodges
author_rank: Frequent Contributor
timestamp: January 04, 2019, 06:51:09 pm
content: Why not row and column? Here is a keypad and microcontroller that you can buy off ebay for less than $2. The keypad has a self-adhesive back andappearsto be weather resistant.Here is more information on my github page:https://github.com/unfrozen/stm8_libs/wiki/lib_keypad:-Scan-generic-(matrix)-keypadMy code is open source, use it as you please. Or if it is really simple, maybe I could code it up for you.EDIT: The USB device is a serial port to connect to your computer (or whatever). That can be found on ebay as low as one dollar.

author: In Vacuo Veritas
author_rank: Frequent Contributor
timestamp: January 04, 2019, 06:59:16 pm
content: Quote from: soldar on January 04, 2019, 05:18:49 pmYou haveindoorweather?

author: soldar
author_rank: Super Contributor
timestamp: January 04, 2019, 08:13:48 pm
content: cdev, yes, I know what kind of keypads you're talking about because I have used them and still have a few around. They were very strong and would last forever indoors. The thing is outdoors dust, condensation, etc. soon corrode the contacts and, in my experience you need to open it up and clean the contacts about once a year.Heck, even thought it is a totally different thing, it seems even TV remotes start having problems after some time even though they are indoors.I would think the two best solutions to protecting the contacts would be using reed contacts or hermetically sealing the keypad and poking the keys through a membrane.I never liked membrane keypads though. They look flimsy and I would need to mount them somehow. I would like some real travel push switches.It is amazing that the electronics have become so cheap that the mechanical parts are the most expensive and where they try to skimp.

author: cdev
author_rank: Super Contributor
timestamp: January 04, 2019, 08:45:57 pm
content: This is the real magic!Quote from: soldar on January 04, 2019, 08:13:48 pmWhat kind of target cost are you trying to stay within? The versatility of something like an SBC and the low cost of everything mass produced (now for Raspberry Pi and Arduino stuff) is pushing the cost of small displays including touch screen ones down lower and lower. If you don't have any experience with Linux I can see how a 'real' computer might seem intimidating but there is so much you can do once you get onto that platform its totally worth in given that now the individual pieces are so cheap. Plus a touch screen would be easier to weatherproof. The problem might be life of the LED illuminating the display, you would likely want to reduce the current to it to extend its life. Also I don't know how well they would stand up to sunlight, both as far as visibility and longevity.Are you going to use a solenoid or similar to open a door lock? Watch out - for example, what happens if somebody props the door open, or the power goes out or any of the many things which can go wrong.

author: Fred27
author_rank: Unknown
timestamp: January 04, 2019, 09:21:45 pm
content: How about a PCB with capacitive touch buttons? Very cheap - even nearly zero of you need a PCB anyway and put the components on the back.Here's an example I'm working on:https://0xfred.wordpress.com/2018/12/07/nfc-antenna-tuning-without-a-vna/

author: Halcyon
author_rank: Unknown
timestamp: January 04, 2019, 10:38:07 pm
content: Quote from: soldar on January 04, 2019, 09:29:07 amJust don't use the RFID part of it. The keypad that Clive demonstrated also supports just PIN entry.

author: soldar
author_rank: Super Contributor
timestamp: January 05, 2019, 12:24:45 am
content: No, here is the situation: I have a couple hundred circuits ready to mount on the wall, with metal housing. I am looking at the possibility of selling them but they are missing the keypad. Without a keypad they are worthless. With a keypad they are ready to install and could probably get, oh, dunno, say $20 ~ $25. So if I can get just the keypad for a target under $5 and definitely under $10 then I might have something. Otherwise the circuits are junk and will have to go in the junk.The circuit connects to the mains, uses a keypad of any number of keys and the four digit code is programmed by connecting those keys to the appropriate terminals. When the correct combination is pressed it activates a relay. It is very simple. The solenoid or lock or whatever is not part of it.So any solutions of the type that I can buy the entire product are not a solution to what I am trying to do which is liquidate a stock I have of circuits. If I can find a good quality keypad for $5 then I can sell the system based on the quality of the keypad. So it has to be something which will have a good expected lifetime of at least seven to ten years exposed to the weather (even if protected from rain by a little projecting cover).It seems what I am looking for is not really commercially available so maybe I could look into making it myself with purchased parts. But, again, I would have to find super cheap switches.

author: tooki
author_rank: Super Contributor
timestamp: January 05, 2019, 01:37:43 am
content: Quote from: In Vacuo Veritas on January 04, 2019, 06:59:16 pmExtremely large structures,like the Boeing plant in Everett, WA, do indeed have indoor weather formations.

author: tooki
author_rank: Super Contributor
timestamp: January 05, 2019, 01:39:19 am
content: Quote from: soldar on January 03, 2019, 10:10:12 pmWeatherproof (and vandal-proof) keypads aren’t cheap. Best bet is to find some Chinese ones I guess.

author: soldar
author_rank: Super Contributor
timestamp: January 05, 2019, 07:50:33 am
content: Quote from: tooki on January 05, 2019, 01:39:19 amYeah but I am surprised there is no offer of, say, keypads from retired public payphones or even new old stock of the same.

author: tooki
author_rank: Super Contributor
timestamp: January 05, 2019, 02:56:54 pm
content: Those tend to be custom made for each phone company. I don’t think they’re using standard parts, and I don’t think they want them getting out. And those would probably be insanely expensive new, since they’re among the most hardcore vandal-proof...

author: cdev
author_rank: Super Contributor
timestamp: January 05, 2019, 08:24:38 pm
content: You can still buy new, old style telco compatible phones. The ones that people of a certain age grew up with. They are much more expensive than the typical cheap ones though.For example, if you want to buy an old style phone, all in red, with a touch tone dial, for conversion to GSM, to use in your car or something. (Only when you are a passenger, not while driving!) Sure!(I think @jaromir made something like that. )But it won't be cheap. It will probably cost you at least $40-50 unless you find some hidden source for them (China?). And it will weigh a lot, for a phone. Like those old phones do.The quality (because the network would need to have a really high quality 600 ohm matching transformer, which I suspect is unobtainium or close to it now) so might not be quite as good as the old Western Electric phones were but it will be very good.Quote from: soldar on January 05, 2019, 07:50:33 amIf you bought just one of those new old phones and disassembled it you would likely be able to find out where the keypad was being made now. I bet that some factory somewhere still makes them or better yet, a modern version that fits the same template, particularly the button's holes. Thats what you need, right?You know who you should ask? At least a few years ago, I remember seeing - and being amazed that there is still some retro telephone system VOIP network which is dedicated to keeping all this old analog phone equipment alive, somewhere.You know how I found it? I have this quite nice motorola ATA that I realized supports pulse dialing phones (!!) So just to see what was the deal with that I went looking for info on what somebody could do with old rotary style telephones. I found that a lot of collectors exist and they have hooked up a system so they can call one another over their old phone equipment. Underneath the old phones exterior it uses VOIP.

author: soldar
author_rank: Super Contributor
timestamp: January 05, 2019, 09:45:09 pm
content: Thanks both but it seems to me not worth pursuing at this point. I was secretly hoping for something like "Army surplus weather-proof, bomb-proof telephone keypads, 100 units for $100 plus $10 shipping, no tax".

author: cdev
author_rank: Super Contributor
timestamp: January 06, 2019, 04:10:54 am
content: The traditional "Western Electric" original touch tone phone is the "2500" model...It is a standard product thats still made, by other companies now, and sold..Infrequently since they last almost forever. These phones are for militant traditionalists.https://www.google.com/search?q="2500"+telephone keypad or something like that.They wear out you know. Eventually. Its been what, almost 40 years..I would start with that.. "2500"This is the company I was trying to remember the name ofhttps://www.cortelco.com/Their motto is "keeping you connected for122 years"

author: soldar
author_rank: Super Contributor
timestamp: January 31, 2019, 12:29:46 pm
content: By chance I found something close to what I am looking for:https://www.electronicsurplus.com/9-045-keypad-twelve-position-telephone-stylehttps://www.electronicsurplus.com/6-039-keypad-alpha-numeric-12-positionThey are row-column rather than 1/n so cannot use them. Also they would need some kind of enclosure which would probably cost more than the keypad itself.Still, that website has some interesting stuff for all junk-lovers like myself.

author: ebclr
author_rank: Super Contributor
timestamp: January 31, 2019, 04:38:29 pm
content: Just in case you need something more robust and more expensivehttps://item.taobao.com/item.htm?spm=a230r.1.14.171.3c4a3d77Daek4Z&id=531227795929&ns=1&abbucket=20#detail

author: soldar
author_rank: Super Contributor
timestamp: January 31, 2019, 06:56:29 pm
content: I also foundhttps://item.taobao.com/item.htm?spm=2013.1.0.0.2ddd37788lj5oL&id=531358953004which is somewhat cheaper. They all seem to be row-column though.Not a bad idea to look into this during my next trip to China.