Observations on OP at sea

[Littlechay]

Here are some notes that I have made whilst experiences on my latest trip are still fresh in my mind. 

Openplotter - Version 0.14.3

Sensors - 
IMU - MPU9150
Temp pressure humidity - BME280
Temperature - 1W
GPS Hat with external antenna

AIS and wind data were shared from my boat PC via UDP over Wifi. AIS I used but never used wind data on the plotter as the screen real-estate is too limited. I have a wind instrument, a windex, and wet finger anyway! 

OCPN - impossible to perform some actions on the small RPi touch screen. Edit a waypoint for example as its impossible to get to the OK button. This is an OCPN scree realestate management issue. 

Compass stops working after 8 hours or so. Restarting sensors sometimes works but on many occasions restarting sensors, signal K and NMEA has no effect and the only way to get it running again is to perform a power off reboot (Normal soft reboot doesn't work). No error messages when running OP from the command line. Processor usage usually runs at about 30% but rises to 50% when this occurs. There may or maynot be some interaction with a bug that I reported in OCPN where if auto-follow is active the heading indicator on screen becomes inactive (COG continues to work).

Maybe connected with the above is that sometimes OCPN slows to a crawl or locks up completely and will not shutdown. Unfortunately in versions of OCPN since 3.something the track is not recorded to the drive in realtime resulting in lost tracks in the event of a crash or forced shutdown (for this reason I know of a few people who are still using ancient versions of OCPN). Hence the track recorded on the Pi plotter for this voyage has huge gaps in it. 

Could the above two issues be related to memory allocated to the track etc. filling up? 

Anybody got the official RPi touch screen to actually work as a touch screen.. i.e. at least get right click to work?

Anybody used something like a game controller as a mouse/button pad? I have never found a touch screen that is really usable at sea on any equipment so for me touch screens on boat nav equipment are only for in port use and planning (quite a few 10 of ks of miles at sea testing new stuff for one of the major manufacturers - they understand but touchscreens sell plotters at the boatshows). When things get tough something else is required, preferably a one handed thing. Maybe one of those presentation handsets? Most people that I know that sail in bouncy stuff regularly use a trackball as their pointer input and that is what I use at the nav desk (Logitech M570 being the usual preferred device). However for the cockpit and watchkeeping station under the hard dodger something else is needed. Ideas please?

Has anybody scripted screen brightness controls to buttons yet? As actions perhaps? I'm thinking of adding two buttons with actions to increment/decrement the brightness setting by 10 at each push? I've been using this from a terminal to adjust screen brightness "echo 255 > /sys/class/backlight/rpi_backlight/brightness"; replacing 255 with anything from 25 to 255 as required. 

Anybody got a better way of doing this or perhaps has done something with Node Red (I haven't got my head around this yet any tutorials out there?). The problem with software brightness is that say you have the brightness turned right down at night and are doing a sail change at sunrise. You come back the plotter and can't see anything on screen therefore it is impossible to navigate to software controls. Hardware wins in this case I think.

Has anybody made any graphic devices in NodeRed or similar for a barograph and a TWS/TWD ribbon similar to those in OCPN? They are crippled in real life use by the fact that the history is limited to the last 20 minutes in the case of the wind graph and that the it is impossible to set the y axis in the case of the OCPN barograph. 

So in summary. The combination of my hardware and OP worked fairly well. Some ergonomics need to be addressed; touchscreen and other I/O issue. But Openplotter and OCPN were a great combination.

Stability and lost data when OCPN fails is a major issue. For the whole trip I also ran OCPN and Nobeltec TZ on W10 on my downstairs boat computer neither of which missed a beat so the issues reported are Openplotter/Pi/Linux specific. 

Cheers
Chris

On the subject of the compass sensor hanging and OCPN slowing to a crawl. - I've updated to the latest version as of yesterday evening and have had it running for 24 hours now with no issues so far. Processor load is much lower in this version running at about 7 - 8 %.

I'm currently moored in a creek and therefore the track file is not building up in memory, but that is the only difference. 

Cheers
Chris