LED communication device, wireless

Hello, I'm looking for help on a project.

-Background for project-

I'm a swimming pool repair tech. During the fall months we close pools for the winter. When we are closing pools it is a 2 person job to evacuate the water out of the plumbing. Essentially one person is near the equipment pad operating a very noisy blower and the other person is next to the pool installing the plugs. During this time there could be a problem and they need to communicate to each other, yelling doesn't help as the blower is too loud to hear anything and hand signals won't work since there isn't typically any line of sight. this is where my idea for a device comes into play

-Project Idea-

I want a set of devices that can be worn on the wrist that have several buttons and corresponding LEDs which would be used to communicate. When "button 1" is pressed "led 1" will light up on "device A" AND "device B". When "button 3" is pressed "led 3" will light up on "device B" AND "device A". An easier way to think about it would be a set of traffic lights that remain in sync wirelessly (with about a 50' range). I would prefer this not to rely on bluetooth or wireless internet to communicate to each other.

I am looking for step by step instructions and parts list to build this device or if someone is interested in building it themselves and is willing to give me an estimate of cost to do so.

Here is a link to a rough mock-up of what the device would look like
https://drive.google.com/file/d/0B52XZ9CfSbEsakNMXzRzS1lLVEE/view?usp=sharing

Hi,
companies like Nordic semi make a range of non bluetooth transceivers (and there are others, Texas Instruments, and I think Microchip, etc), these work at 2.5Ghz, so the antennas would be small, which would suit a wrist based device. There could be problems with range though, and detuning can be a problem with whip antennae if close to the body. Loop antennas best here, but often larger, although there are some SMD loops available. I designed a telemetry device working up to 30 metres using a Nordic part, see http://www.telerein.co.nz/. There are small modules based on these chip sets available for developers to get started.
Linx Technologies make a range of wireless devices for frequencies between 400 and 900MHz.
If designing from scratch, you have to be aware of issues around spurious emissions, so need to follow guidelines set down by the chip manufacturers, they often have preferred layouts which have been tested to meet RFI standards. In your case this is unlikely to be a problem, looking at the application. Using pre-built modules will usually take care of this problem.
A small micro would handle the encode/decode push button and LED side of it.
Have you set a size for the wrist enclosure.
Hope that is of some help,
Richard

I provide products to the Deaf and Hard of Hearing in Oz. The best bet is vibration for hands free notification.

Not everyone will look at a receiver unit all the time for a light to go off.

There is a company in Australia that has overseas distributors that maybe useful, but I have not found anything that is entirely portable as yet. My stuff is non configurable so will not suit best.

If you are following a set procedure, with some expectation of what is to happen, and when, then vibration may not be needed, since the person at the receiving end will be keeping an eye on the receiver. What you will certainly need though, is an acknowledgment system, to confirm the command sent has been received and executed.
This is necessary in case of a wireless link failure(out of range etc), or failure of the person at the other end to act on the command.
Cheers,
Richard

Can you not use mobile phones? You can even get wrist mounted mobile phones if you really want it on your wrist.

Forgot to mention the supplier we have here Elsema http://www.elsema.com/distributors-overseas.htm

There almost certainly more suppliers out there, some more portable than Elsema.

Another system i provide for clients are pagers. One supplier is http://www.wavelink.com.au/ but again there should be more. I supplied to a client a transmitter and pager solution to allow the Deaf client to receive predetermined text message sent from a single push button. There are transmitters with more than one button as well. It has been a while since I have supplied a system, but I think I still have contact with the distributor.

Im thinking I might just have to stick with a solution like walkie-talkies. Hopefully they can get loud enough to hear over the blower though.

walkie-talkies might work, see if you can find one that will take an external earpiece and mike, or a head set, some may even have a noise cancelling system, worth a look around.
cheers,
Richard