Need Something Built for me... any sugestions?

[Mister35]

Hi, I own a business and need a relatively simple device built for me.  I have searched everywhere and this product dosn't exist. 

All it is, is a Key Holder that Beeps every 20 seconds if the Key is removed. 

Basically, take on of these: http://www.officedepot.com/a/products/195529/Eldon-8-Key-Tag-Rack/

Glue Some magnets to the Tags, and use Magnetic switches attached behind the holder.  Key is removed, the thing beeps at 20 second intervals.

Would like it to Plug in to AC outlet.

I would like it to be nice and sturdy.

Anyone have any ideas of where I can get this made for me?  Anyone want to make it.  Ill pay for it of coarse.

Employees have a bad habbit of taking keys to use them, then setting them down somewhere, or putting them in their pocket.  This beeping would prevent that from happening.

Let me know if yall have any ideas.

Keep in mind, It will get heavy use and should be built really sturdy.

Thanks - Steven

[jwatte]

What most places do is to attach a really big sprocket or metal plate to the key. I'm talking half a pound of steel. Then you aren't as likely to accidentally put it in your pocket.

The problem with the key beeping is that it requires a battery to do that. It can be done, but I think the entire solution would be somewhat unwieldy.

I'd estimate design and prototype cost for a one-off somewhere between $3k and $10k, depending on what place you end up with.

[Mister35]

Wow, I was thinking about someone who has some tinkering experience building one with parts from radio shack.

Its a prety simple device.

I guess what im stopped at is this:  How do I make it beep only once every 20 seconds?  I can get a Buzzer or beeper, but I only want it to go every 20 seconds.  How would I make that work?

[jwatte]

I only want it to go every 20 seconds.  How would I make that work?

You can use a 555 timer, for example. Or a small ATtiny microcontroller like the ATtiny25, which would be total overkill, and you'd want to make sure it sits in sleep mode most of the time to save on battery, but it would be an easy solution to implement.

Regarding the cost estimate: The problem with having other people doing things for you is that they need to spend a lot of their time figuring out what it is you really need done. You also mentioned it had to be robust. One of many things that need to be solved: Charging the key fob battery while they key is on the rack end up. This is hard to make so it works even when people put the key back sloppily. You might be able to use the charging current as a detector that the key should not beep, so a poorly put-back key will keep beeping, perhaps.

In general, in engineering: The first one is always expensive -- then you can do work to make 10,000 ones very cheaply :-)

[Soeren]

Hi,

All it is, is a Key Holder that Beeps every 20 seconds if the Key is removed. 

Which part should beep, the key or the locker?
And how loud?

Glue Some magnets to the Tags, and use Magnetic switches attached behind the holder.  Key is removed, the thing beeps at 20 second intervals.

I assume it's the locker/rack you want to make the noise, but will that help any?

Would like it to Plug in to AC outlet.

Best way to do that is by using a "wall wart"/mains adapter, as, if anyone build you a power supply and your office burn down from a flaw in the components it's made of, the one building it will be liable and can be sued dry. With an adapter, only the manufacturer of the adapter can be sued.

I would like it to be nice and sturdy.

Nice like...?
Sturdy like...?
We don't know your taste or your references (which may be very different from ours, so please be specific). "Nice" may be hard to describe, but what level of abuse does it need to withstand?

Anyone have any ideas of where I can get this made for me?  Anyone want to make it.  Ill pay for it of coarse.

I could make you such an item, but even if jwatte is quite off the mark (like a factor 10 or so if we're talking my salary, which is higher than US engineers same), I don't think you'd like having to pay for shipping from Denmark, nor the higher component prices.
If I'm wrong here, you're welcome to send me a PM.
(If nothing else, I could design it and either you or I could find someone to put it together - Which city/state BTW?)

Employees have a bad habbit of taking keys to use them, then setting them down somewhere, or putting them in their pocket.  This beeping would prevent that from happening.

If it's not the key part that beeps, how would it prevent an employee from pocketing the key?

Let me know if yall have any ideas.

Keep in mind, It will get heavy use and should be built really sturdy.

What trade?
I've built handheld terminals for use by cargo train handlers using them with gloves rougher than welding gloves


A suggestion:
Assuming they need the key for say 20 minutes on average, it would perhaps be  "polite" to hold the beeping off for that time. Then starting with single beeps for some interval, then slightly more aggressive double beeps for a while and then a really annoying tripple beep or something like that (could be gradually increased as well, just like the intervals could be shortened gradually).

What if two (or more) keys are missing and one is returned.

How about a rotor light or a xenon flasher/strobo to assist


To really get the ideas floating, it would help knowing...
How rough treatment are likely?
How many keys?
How loud
Should the key locker/rack be lockable?

If the locker beeps and it annoys people, wouldn't they just turn it off?

[Soeren]

Hi,

In general, in engineering: The first one is always expensive -- then you can do work to make 10,000 ones very cheaply :-)

You're really way out of synch with reality, estimating as you did - please leave the engineering estimates to engineers 

And besides, we still need Mister35/Steven to clarify a few things about the project, before a realistic estimate can be made, but anyone demanding $3k or more for this little project is either a blatant fraud, or slower than a handicapped snail in molasses (which should never go on the customers bill)!

[Mister35]

Soren, Thanks. 

I want the Key Holder to Beep.  Not the Keys.

Not Crazy loud, just to alert us that the key is not there.  We stand within 6 feet of the Key rack.

The keys never leave the sales floor.  The employees unlock a case, get a DVD, or Piece of Jewelry Out for a customer, and then return the key to the Rack.  I want the Key to be back on the rack within a couple minutes.

Each key is taken off the rack about 20 times per day.

It does not need to be prety, just sturdy.

I suppose you could make the Key fob beep instead of the rack.  I think the Rack would be better though.

The purpose of the beep is to remind the employee to hang the key back up.  If the rack beeps, everyone will be aware, and the keys will not get misplaced.
They will not turn it off or unplug it.  They understand the purpose and we all would be happy if the keys stop getting misplaced.

It would be a good idea if it didnt start beeping for 2 minutes.  Good idea.

Power adapter is fine.  Battery powered is fine even if its a big deal.  I can replace a 9 volt battery every now and then.

Rack does not need to lock.

No light needed.

Cost:  Honestly, I wasnt thinking it would be much at all.  I was thinking $50 in parts from Radio shack, and some money for the build.

I guess I would be happy to pay up to $400 total for the item.  I cant tell you how much of a hastle it is to deal with the keys missing.

If my price estimate is way way off, let me know,  I have no idea and am just exploring. 

I really do apreciate your input.  Let me know what you think.

[Soeren]

Hi,

Power adapter is fine.  Battery powered is fine even if its a big deal.  I can replace a 9 volt battery every now and then.

Batteries can be a nuisance, but made right, it may still be a better solution in the long run (see below).

Cost:  Honestly, I wasnt thinking it would be much at all.  I was thinking $50 in parts from Radio shack, and some money for the build.

Now that you explained the use of it, I think I have the entire concept ready in my head, but just to be absolutely sure, here's what I picture:
A solid key rack with a peg of sorts for each key.
All keys in place => nothing happens
One or more keys missing => wait ~2 minutes, then beep every ~20 second until key returned.

A flat magnet can be installed on each key hanger (the colored parts in this picture)


Estimate of hardware costs:
Components for less than $10, plus around $1 per key
(The above is ex. VAT and shipping, from Mouser and Supermagnets - Rat Shack haven't got what's needed)

An extra magnet per key can be used to keep power drain to zero, when all keys are in place. That would make battery use a sensible solution, as 3 AA size cells would last for years and would be "greener" than a mains adapter. That would add a battery holder, but would save the mains adapter and the constant power it requires, whether current is drawn or not.

I assume it will be cheapest to use one, or a number, of the kind of racks you linked to in your first post (they do have a slightly cheaper one as well), but I cannot judge how sturdy they are from the pictures. They seem to be made of hard plastic.

How many keys do you need it to hold? (You might wanna make room for future keys and just keep the hangers in place for now(?))
What area can they occupy (height/width), one row or how many rows/columns?

I guess I would be happy to pay up to $400 total for the item.  I cant tell you how much of a hastle it is to deal with the keys missing.

I see several scenarios:
1 - Local tinkerer makes it all
2 - I design it and make the program for the controller, local tinkerer assembles, burn program into microcontroller and wires it up.
3 - I design it and deliver a matrix board, programmed and all, local tinkerer handles the acquisition and wiring of switches and magnets etc. (I'll deliver an easy to follow wiring diagram, instructions and email support if needed by the tinkerer).
4 - I deliver a (dare I say) turnkey solution

The last one won't happen at anywhere near $400, for a number of reasons; Denmark is a very expensive country. Shipping a parcel of between 1kg and 2kg to the USA is slightly above $50 for "Economy", which is 8..9 work days just to reach your shores and for 5..6 work days it's ~$60. The price estimate on reeds and magnets is when ordered from US web sites and you have much lower VAT and national shipping than we do. For goods bought overseas and sent to Denmark, Danish duty taxes apply (and for a couple of years now, the Danish Postal Service has been allowed a fee of ~$30 to cash in any appliccable import taxes for the Revenue Service). I'd have to involve a machine shop as well and all in all, it would make it hideously expensive.

Lastly, I'm not cheap labour, but perhaps we can work out a Christmas Special on solution #3, which I think is the most sensible solution for you, as you mentioned jewelry and my spouse is nuts about wrist watches and bracelets soaked in "bling".

If you'd rather have it all made locally, no problem at all

[Mister35]

I am good with a Soldering Iron and Can assemble things.  If I know exactly what to get and have instructions, I can put it together.

"How many keys do you need it to hold? (You might wanna make room for future keys and just keep the hangers in place for now(?))
What area can they occupy (height/width), one row or how many rows/columns?"

The Rack int he link is Fine.  8 Keys Tags is enough.  I can hang the rack on a wall, so I have plenty of room.

For option 3, what kind of Price are you thinking?

[MrWizard]

Now the finer details are clear better exchange price and details through Private Message...

Glad you can do business !

[jwatte]

You're really way out of synch with reality, estimating as you did - please leave the engineering estimates to engineers 

I live and work in the silicon valley. Designing and building this thing with beeping keys for less than $3k is unlikely to happen here. Lucky you to live in a cheaper part of the world :-)

I want the Key Holder to Beep.  Not the Keys.

That changes things! I had read the initial problem description as "they key has to beep to remind the holder to return it."

Soren had the same question:

If it's not the key part that beeps, how would it prevent an employee from pocketing the key?

Having a portable beeper with battery and charger in each key fob gets expensive and complicated, but solves the problem for the employee holding the key (rather than the office.)

Having the holder beep when at least one key is missing is easier. Glad you could help the guy -- post a photo when you're done :-)



Also, if a hack is good enough, here's how to build this yourself in a couple of hours:

1) Components:
- 1 existing key rack
- 8 magnetic switches ($5 each)
- 1 Arduino Uno ($25)
- 1 Wall wart ($8)
- 1 Radio Shack buzzer ($6)
- 1 Project enclosure ($8)
- Various bits of glue, string, wire, bubblegum, Dremel, etc

2) Instructions:
- install sensor part of magnetic switches behind key fobs
- run the sensor wires to ground, and digital input pins of Arduino
- run the buzzer to Arduino pin and ground (depending on current, may need a switching transistor too)
- glue magnet part of sensors to back of key fobs
- write Arduino code to detect missing/present keys and beep when needed
- mount wires, Arduino, and buzzer in project enclosure
- connect to wall wart

3) Arduino code suggestion

The code would look something like:

Code: [Select]

unsigned long keyLastSeen[NUM_KEYS];
unsigned long lastBeepTime;

setup() {
  set each of the digital inputs to input
  set the buzzer output to digital output
  initialize all "key last seen" values to current time
  set lastBeepTime to current time
}

loop() {
  unsigned long longestAbsence = 0;
  for each key index {
    if (key present) set keyLastSeen[index] to current time
    longestAbsence = max(longestAbsence, current time - keyLastSeen[index]);
  }
  if (longestAbsence < INITIAL_MISSING_TIME) {
    turn beep pin off
    lastBeepTime = current time;
  }
  else if (current time - lastBeepTime < BEEP_TIME) {
    turn beep pin on;
  }
  else if (current time - lastBeepTime < BEEP_INTERVAL) {
    turn beep pin off;
  }
  else {
    lastBeepTime = current time;
  }
}


This is pseudo-code, but should translate easily to an Arduino sketch.

[Mister35]

Thats more what I was looking for.  the hard part was the beeping part.  I can do all of it but the Arduino.  I see I need a program to do it.  Then I just plug it into my computer and program it?  Will a newbie with a good physics/engineering mind be able to do this easily?

[jwatte]

If you have never written software before, then getting over the first hump will be painful. It always is, because it's much more abstract than electronics/mechanics.
There are some excellent Arduino programming tutorials on the Arduino site: http://www.arduino.cc/ that can walk you through it, but expect it to be many late nights before you get to your goal.
Might be easier to pay Soren to do it, if it's a business expense and you don't have any other reason to learn software development anyway :-)

[Mister35]

Alright, good idea.

Ill wait for Sorens reply.

[Soeren]

Hi,

I live and work in the silicon valley.

All kinds of people do, but a lot of them ain't  engineers.

Designing and building this thing with beeping keys for less than $3k is unlikely to happen here.

Oh, I didn't think they were that slow over there... But well Danish Design is a specialty of course

Lucky you to live in a cheaper part of the world :-)

Au contraire I'm afraid. Denmark is one of the (if not the) most expensive countries in the world.

[Soeren]

Hi,

I am good with a Soldering Iron and Can assemble things.  If I know exactly what to get and have instructions, I can put it together.

Piece of cake then

The Rack int he link is Fine.  8 Keys Tags is enough.  I can hang the rack on a wall, so I have plenty of room.

Oh, I pictured something like 50..100 keys - Silly me. This should be an easy job for you on a rainy afternoon.

For option 3, what kind of Price are you thinking?

Something like a nice (or perhaps exaggerated is a better word) Swarowski filled  ladies watch with a large dial. Have you got anything like that in your selection?

[jwatte]

Au contraire I'm afraid. Denmark is one of the (if not the) most expensive countries in the world.

Close.

You would need around 5,541.78$ (31,323.82kr) in San Francisco, CA to maintain
the same standard of life that you can have with 31,000.00kr in Copenhagen

http://www.numbeo.com/cost-of-living/compare_cities.jsp?country1=Denmark&city1=Copenhagen&country2=United+States&city2=San+Francisco%2C+CA

I've found engineer salaries to generally be higher in the valley than in Scandinavia, which greatly influences contracting rates.
Given that this project is a one-off build-at-home without anything complex like I first thought, though, that's academic at this point.

[Mister35]

Soren, I try to stay away from ladies watches for the most part they are hard to sell, especially with a large face.  I will be back at the store on Monday and will see what I have.  What you are describing is almost exclusively made by Bulova.  I will reply on Monday.  Or maybee Wednesday as Monday is one of our busiest days.

[Mister35]

Soren, I Either have Ceap womens watches, or one really nice Tag.  The Tag has a blue face and diamond bezel.  However, its priced at $700.  These are all used BTW.  I do go through a fair amount of watches, but not as many ladies watches, as they are very hard to sell.  I may have a nice one in the future.

If I cant find a watch to trade, how much would you want to program the board and deliver it with instructions and a parts list.?

[Soeren]

Hi,

If I cant find a watch to trade, how much would you want to program the board and deliver it with instructions and a parts list.?

I'd rather go for naturalia really.
I'm smashed for today, but will get to it tomorrow.
I wasn't thinking brand name watches at all. Hope I'm not offending you by assuming that you may have cheapish watches, but I'll try to send you a photo of some of her watches tomorrow.

[Mister35]

No offence, we have all watches.  Mostly Mens, but we are a used outfit, so we take high end and low end.

Let me know what you come up with and I will let you know if I get anything else in stock.

[Mister35]

Gucci 600l, Green and red face......?

[Mister35]

Any Luck Soren?  SHould we talk via private email?

[Mister35]

Anyo9ne still interested in building this?  Or simply programming the chip as discussed?  Soren, still got any free time?