YAPP ideas

AngusMcDoon said:
Well the volatile storage is in RAM and goes when powered down. Did you mean the persistent storage? If so, one of these solutions...

1) No file system - nothing to corrupt. All code is in flash and settings are in a bit of eeprom which are protected by a checksum and maybe a backup copy. If the checksum check fails settings are reinitialised to default or the backup copy is used. YAPPs are like this.

2) Read only file system. It's probably running linux. This can be loaded from a read only file system at boot.

3) Transactional or journaling file system. Big heavy solution. Unlikely to be used in a small device like this.
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Yes of course I meant persistent duh!

What i don't quite understand is how any config is then possible? Or maybe it isn't!
 
roblpm said:
What i don't quite understand is how any config is then possible? Or maybe it isn't!
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Routers often have a web server running on them. You connect by ethernet and fill in fields on forms. Maybe it's like that for the ethernet enabled ones. My NMEA183/Seatalk bridge YAPP that is forthcoming is configured by a simple command line interface over a serial connection.
 
I would be interested in a wireless autopilot control.
Re the failed large screen display, how about a wireless two line LCD nmea to keep in your pocket? I would find that very useful.

M
 
AngusMcDoon said:
Well the volatile storage is in RAM and goes when powered down. Did you mean the persistent storage? If so, one of these solutions...

1) No file system - nothing to corrupt. All code is in flash and settings are in a bit of eeprom which are protected by a checksum and maybe a backup copy. If the checksum check fails settings are reinitialised to default or the backup copy is used. YAPPs are like this.

2) Read only file system. It's probably running linux. This can be loaded from a read only file system at boot.

3) Transactional or journaling file system. Big heavy solution. Unlikely to be used in a small device like this.
Click to expand...
Its got a web browse to configure it, I got it working on the boat today, RO4800 producing the AIS it runs linux, he provides a command line thingy to get in if you want to play with the linux, it has an RJ45 connector if you want to connect by wire, it has two inputs which are configurable to set the speeds bgoing in so tomoz I get the B nd G nmea to go in on the other input and hopefully it will give me remote instruments and AISS
 
Forty_Two said:
Apart from power, the other RPi issue is shutting down. If you use it as a PC then you expect a shutdown process but if it's doing some miscellaneous task you can't just switch it off because you will corrupt the SD card.
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In practice I've never had a problem with just pulling the power from my pi (filesystem settings all default raspbian) but your point is valid. The obvious solution is to mount everything read only: use a small memory based filesystem for tmp and symlink anything which something needs to write to to that. Obviously the pi doesn't have stuff loads of memory so there's the hybrid solution of combing a memory-based /tmp with a /var with journaling cranked to maximum. To make changes obviously a quick mount -o remount,rw. Doing and documenting that has been on my to do list for the past year. Might get round to it soon....
 
Hi Angus. Re the AP remote (wired). You may recall that I have altered your original to add a third button Auto/Standby (it needed a wire connection on the PCB and simple code changes). One might be able to add a 4th button (eg MoB) but I haven't tested it.

I'm still keen on:
a) a windlass rode counter (including counting free-fall)
b) an NMEA0183 box that can input (probably only) VDM at 38,400 and other sentences at 4,800 and output it all at 4,800 - and I don't mind if some VDM sentences get lost but it would be nice if they could be buffered

Cheers, Andrew
 
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