MOB Alarm

elton

Well-Known Member
Joined
19 Oct 2005
Messages
17,482
Location
Durham, England
www.boatit.co.uk
Following several threads on the subject, namely http://www.ybw.com/forums/showthread.php?366080-Man-Overboard-System-Worth-it-or-gimmicks, http://www.ybw.com/forums/showthread.php?373360-Yacht-aground-and-skipper-missing&highlight=lifetag and this http://www.ybw.com/forums/showthread.php?374980-Bluetooth-Headsets&p=4402494#post4402494, I wrote an app to alert of missing crew. Briefly, it's Android only, and runs on Bluetooth and GPS capable phones or tablets. It monitors Bluetooth devices carried by crew, and sounds an alert if they go out of range or if the device they're carrying fails (eg due to water ingress). The Bluetooth devices can be any Class 1 or 2 device, which must remain discoverable. I've tested it running on my Archos G9 tablet, monitoring a range of devices, including Nokia 6300 and 3109 phones, a Navman B10 (GPS puck), an Advent Bluetooth dongle, and my neighbour's Samsung television set. I'm happy to report that it works exactly as designed.

It isn't for sale yet, so this is not an advert. However, I do need to test it running on something other than my tablet. So if anyone would like a preview, in the form of a beta test download, PM me your gmail address, and I'll set you up as a tester on the Android development console, and I'll email you the app (within the next week or so). As it's completely untested on anything other than my Archos tablet, there's absolutely no guarantee it'll work on your phone. In particular it's unlikely to work on devices with an Android version less than 3.1.

Some screenshots:

The name in the third column is the actual device name; the second column shows the user-assigned nickname; the first column is an icon indicating whether the device is paired with this one (though it makes no difference); the fourth column indicates the device status. Devices can be put on 'ignore', or will show 'Ok' or 'Missing'. When missing, the row will flash and a hooter will sound. The last known position of the device will be displayed in the right column, if it goes missing. If there was no GPS coverage at the time of loss, this is indicated. Device "nicknames" are retained in a database by the app, and used in subsequent sessions.

Minotaur_1.jpg


Minotaur_2.jpg


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Would love to try your MOB software. I have a HTC phone for my sins.

I have often wonder if blue tooth could be used in this way. I have also wondered if the blue tooth ear phones that are used as hand free devices could be used to communications with each other to aid communications between helm and fordeck.
 
Would love to try your MOB software. I have a HTC phone for my sins.

I have often wonder if blue tooth could be used in this way. I have also wondered if the blue tooth ear phones that are used as hand free devices could be used to communications with each other to aid communications between helm and fordeck.
Hi Roger, if you pm your Gmail address, I can send you a copy. You'd have to change a setting in your phone to allow installation of "non-market apps" - but that's quite simple.
 
I would love to try it, but I have no idea if my BT headsets can remain discoverable. Got any info on ones that do?
I don't know which headsets remain discoverable, but it's quite simple to check whether yours do; just select settings on your phone, then select Bluetooth; you should see a list of Bluetooth devices; select the settings for for it, then "Unpair". Then turn off the headset, and on again. Go into Bluetooth settings on the phone, and "Search for Devices". Wait for 5 or 10 minutes, then search again. Most of the headsets that don't remain discoverable, become "undiscoverable" within a few minutes of power-on. As an alternative to a headset, you can use any old phone with Bluetooth; it doesn't need to have any phone service. I used a couple of old Nokias I had lying about.
 
I have also wondered if the blue tooth ear phones that are used as hand free devices could be used to communications with each other to aid communications between helm and fordeck.

Not directly, but I think a phone app could probably be written to relay audio from one headset to another. One issue might be the limited bandwidth of a Bluetooth "PAN" network - when it was briefly covered in my hardware course at Uni we learned that there was just enough to carry one audio stream with all the quality options turned on - you might fit two or three with lesser settings, or perhaps the bandwidth of Bluetooth has increased dramatically in the last decade.

Pete
 
Not wishing to be a cold water thrower, but most crew tend not to like cold water thrown over their mobile phones and tend to leave them cluttering up the chart table:)
Then they'll be left to drown ;)

But seriously, it doesn't have to be a phone; most Bluetooth devices will do. Also, it could be an old phone - not Android; even one without a sim card.
 
Not wishing to be a cold water thrower, but most crew tend not to like cold water thrown over their mobile phones and tend to leave them cluttering up the chart table:)

Doesn't have to be their mobile. I reckon most of us could assemble a collection of obsolete phones to use as MOB tags without too much difficulty. I know I have two in a drawer which wouldn't fetch enough at Mazuma to be worth sending in.

Pete
 
I know these cost a little and the potential App looks bloated but the actual remote devices look small enough for you to even put into each lifejacket on board....
http://www.indiegogo.com/projects/sticknfind-bluetooth-powered-ultra-small-location-stickers

Thanks - that looks like an ideal companion to Elton's app, for those who don't mind spending a little (about $25 each) for something a bit slicker than an obsolete Nokia.

Still not really for me as I don't like using phones and tablets for core functions on board (it's not an entirely rational position so don't try to persuade me otherwise :) ), but could be useful for some.

Does Elton's app need to be running in the foreground to work, or can it be running behind a chart or tide app and then jump to the foreground if a tag is lost?

Pete
 
Does Elton's app need to be running in the foreground to work, or can it be running behind a chart or tide app and then jump to the foreground if a tag is lost?
It can run quite happily in the background, so notifications and alarms occur as normal, but at present it's 'relegated' to a low priority task by the OS when it goes to the background, so it may be stopped without warning according to the needs of the system. It's an issue I'll address in due course.
 
Wonder if those little bluetooth gps devices would work, cheap enough to give one to each crew and stick in a small waterproof wallet and would give holders location info to the central unit, I have one and could test with a galaxy tab running jellybean, Very interesting ap.
 
Wonder if those little bluetooth gps devices would work, cheap enough to give one to each crew and stick in a small waterproof wallet and would give holders location info to the central unit

Well, it will give that info for as long as you don't need it (because the crew's location is the same as the boat's). Then, when they fall overboard and you do need it, you will stop receiving their position because they are out of bluetooth range and the transmitter is underwater.

With short-range systems like bluetooth and Lifetag, the idea is to sound an alarm when the radio link is broken. To maintain a link, and actively track the casualty, you need something more powerful like an AIS SART or a 121.5MHz homer.

Pete
 
Elton... I have only just managed to check out your screenshots... Recording the GPS position from the phone GPS at the point in time connectivity is lost to a remote device... awesome.. Looks good.
 
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