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seandepagnier · 28-11-2015, 08:25

I think we should make preserve chart scale when switching charts enabled by default from a clean install.

rabbi · 29-11-2015, 05:04

I have a feature request to improve MOB handling:

We do only shorthanded cruises and the dangers of MOB while the off-watch partner is sleeping somewhat bothers me. Imagine a situation like the one pete Hill faced.

I think something like a Raymarine Lifetag would at least help in these situations as even if it still goes unnoticed for some time one could see where the MOB happened.

My idea is the following:
Many / most current computers have bluetooth capabilities. Why not connect the PC to a BT device and check periodically if the connection is alive. If its dead for longer than xy seconds we assume a MOB situation, place a marker and sound an alarm. Maybe also change the AP heading into the wind or run in circles around the MOB position if under engine but this needs to be configurable as this could be dangerous for the boat and the crew.

The device could be any device, like a smartphone or maybe just a cheap BT headset (these start around 5 USD on ebay so I don't care if they are not waterproof).

I know one has to live with sporadic false alarms due to lost connections, dead headset batteries, interference, etc. Of course this can only work for smaller fibreglass or wooden boats as BT range is limited. But I guess this is a good portion of the OpenCPN installations out there. I tried it on our Mahe 36 catamaran and there is full BT coverage everywhere with the PC installed at the nav station.

what do you think?

CarCode · 29-11-2015, 05:15

Quote:

Originally Posted by rabbi

what do you think?

Why make it so complicated? Simply use the dead-man alarm of the watchdog_pi plugin.

Gerhard

rabbi · 29-11-2015, 06:51

Quote:

Originally Posted by CarCode

Why make it so complicated? Simply use the dead-man alarm of the watchdog_pi plugin.

Gerhard

Deadman is a manual workaround but not an automated solution.

seandepagnier · 29-11-2015, 12:47

rabbi,

I like your idea, but I don't know if the bluetooth headset can work for this or is the best device to use. Maybe it is possible however with any bluetooth device, but even then it would take a while to notice it is missing. I can experiment with this and make it working under linux with the watchdog plugin but I don't think it will work on any other OS.

bluetooth is cheap but not ideal for this. Instead we would like to have something which just transmits a gps location and works over a longer range than bluetooth. This allows you to find the person in the dark or difficult conditions.

For myself I don't need to worry about it as I am alone.

RaymondR · 29-11-2015, 15:05

rabi,

I like it, loop back on the loss of Bluetooth or wifi signal. Drop a mark on the chart display or for single handers have something connected to an engine kill solenoid or full on rudder via the autopilot. Bluetooth and wifi are both cheap and multiple units on ones belt for redundancy could provide a reliable signal. Good project for the electronic DIYers amongst us.

rgleason · 29-11-2015, 15:51

Rabbi and RaymondR,
Please make an Opencpn Feature Request in Tracker.
First register here OpenCPN::Tracker Register new user
Then login and add a feature request, with sufficient detail to understand.
Thanks

rabbi · 29-11-2015, 16:19

Quote:

Originally Posted by boat_alexandra

rabbi,

I like your idea, but I don't know if the bluetooth headset can work for this or is the best device to use. Maybe it is possible however with any bluetooth device, but even then it would take a while to notice it is missing. I can experiment with this and make it working under linux with the watchdog plugin but I don't think it will work on any other OS.

bluetooth is cheap but not ideal for this. Instead we would like to have something which just transmits a gps location and works over a longer range than bluetooth. This allows you to find the person in the dark or difficult conditions.

For myself I don't need to worry about it as I am alone.

This BT idea is just to automatically record a MOB position and ring an alarm. It's not for homing in on the person lost.

Headset should be OK just as any other device. The good about headsets is they are dead cheap, easily available and have a good battery life.
If we can get an alarm within a minute or so it should be good enough. Quicker is better of course.

Something with GPS and longer range will be much more expensive . We have a handheld vhf with dsc for this but its not an automatic alarm and has a battery life of just a few hours. Also I have no idea what OpenCPN will do if it receives a dsc distress call. Will it record the distress VHF position or also the ship's position?

hoolie · 03-12-2015, 06:48

I bought some of these devices that do pretty well what you're looking for (that's why I bought them!)

The BT master device records the position it was at when contact is lost with a slave and sounds an alarm. My phone handles five devices without problem apart from occasional false alarms when BT contact is dodgy. I have yet to try them with my on-board PC as it needs an Android emulator to run the app.

Of course it's still a standalone system and doesn't integrate with OpenCPN yet.

rabbi · 03-12-2015, 07:05

Yes! These items are even better then headsets.
Now just integrate it into opencpn

bcn · 03-12-2015, 07:33

These devices are known as BT beacons.
There are a lot for iOS and Android from the shelf.

There does exist at least one generic library for Windows and there should be as well something for Linux. Remember that you will need a BT device/chip set which supports the low power beacon mode.

Happy tinkering!