There is no compass module
There is no compass module onboard and we rely on the GPS courses. I can see that a compass would probably optimize the waypoint turn but for now I’m very satisfied with the way it handles.
It isn’t critical that the line between the waypoints is not completely straight as long as we get enough depth and GPS readings for the mapping.
As this is a job
As this is a job commissioned by the University of Oslo, and the boat and software is their property, I can’t really release it as open-source. I’ll check and get back to you on that.
The depth sounder
Is any information available on the depth sounder? TIA.
The sensor is an Airmar
The sensor is an Airmar DST800 http://www.gpsmart.ca/item7002.htm
That gives you standard NMEA 0183 sentences over a serial line.
I’m inspired
So nice to see all the work that goes in there. Would be nice to have a better sonar under there that can actually show shapes of the bottom (like the fancy fishfinders do). Or add some undewatervideo device to do some serious treasure hunting. With such clear water it should be possible to get proper images up to 30 meters deep (on sunny days). Just publish the images and scans on a website and let inet-volunteers look for treasures or scandinavian sea monsters :) I’m longing back to my boat days… Was it very hard to setup the GPS system with the ardupilot?
ps Don’t add the location or the treasures might be gone swiftly 
Actually we didn’t follow
Actually we didn’t follow the Ardupilot route but instead wrote our own navigational software. The Ardupilot was a bit over kill for our needs. I even had to write my own NMEA decode functions as the NMEA library I used stole the entire RAM and I couldn’t get it to work with the SDfat lib.
Arduino sketch
I have added the Arduino sketch now if you want to have a look.
Amazing stuff. Great
Amazing stuff. Great craftmanship ;D
What happened to the solar powering idea? Maybe you could add a Li-po and some panels to replace that heavy leadacid batt.
The solar panel idea is put on hold for the time being
Thanks for your kind comments ArvotroN
When the first hull was completed it was more stable then I had foreseen and then it struck me that instead of having a single catamaran, two boats working independent of each other would complete the job faster.
We could still use some more efficient batteries like LiFePO4 http://www.batteryspace.com/lifepo4battery128v20ah256wh60aratewopcm-replaceslawith10timeslongerlife.aspx or something similar but for the time being we are stuck with the lead acid ones.
Wow, just amazing work!And
Wow, just amazing work!
And thanks for all the details, and nice covering!!
(and thanks to rik for chillin it!)
M Hull
Hi Geir,
have you ever looked at the M-Hulls? They use the bow wave to generate lift (pretty much as the hydroplanes do) but where the hydroplanes use a single tunnel they actually use 4. Really interesting stuff, us navy has the M80 stilleto, it’s fast, can carry big loads and has low drag. You might be able to find a better balance between powerconsumption, speed (and with that range) as you do with the sailingboat hull (which has to go slow to prevent it from getting draggy). Building one will take longer however. Take a look at the helicopter deck, nice place for a solar panel
There are more pics arround on the net, if you look at the hull from the bottom side it would basically be a cat with sideskirts to catch the bowwaves (the tunnels are a lot smaller towards the back of the boat increasing pressure towards the middle i guess, that's probably the tricky part if you build one yourself, the cg has to be right but also the presure rangew). As the cat's are some of the lowest drag hull designs this will even be a bit better as it returns some of the energy transfered to the waves.
My hands are itching and I smell wood the whole day...... ;)
i like this one
I like this hull.
Is there any 3d model ,or something to guide us in order to construct it?
Google
Google on “M80 Stiletto” there are some you can buy.
I think that hull design is
I think that hull design is beyond my building skills and not exactly what we are looking for. What we need is a boat that can be broken down and easily carried (by backpacks) to lakes that has no nearby roads.
As SEA RENDERING is more or less a working prototype it might be redesigned later to accommodate the solar panel and thereby give it unlimited range for the larger lakes. As for now we will keep this design and run some more tests to further optimize the system.
This is an amazing project.
This is an amazing project. I am also quite interested in how you created the plug for your mould?
The plug was constructed the following way
I designed the shape of the hull using the free version of Delftship http://www.delftship.net/ (I also added my design as an attachment if you would have a look (zip file)).
Then I printed out the linespan drawing 1:1 (several copies) and glued them onto 6mm building board. Cut out the shape and had a rough shape of the hull. (attached a PDF of the linespan drawing)
After mounting the bulkheads I filled the void with building foam and cut it back.
Then several layers of plaster and sanding before I added two coats of gelcoat. More sanding and polishing before the plug was ready to be cast into a mould.
Sins the shape of the plug had steep angles I decided to go for a split mould. That is extra work but it was worth it. With this mould I can reproduce as many boats I like, and by the likes of it I might have to build a couple more.
Simple and effective design,
Simple and effective design, cool work man… I love it. By the way my ABE its under redisign…
One question- How long last the battery:_?
The batteries are rated at
The batteries are rated at 12Ah and with the two in parallel I should have 24Ah on board. With the motor and all systems running it pulls about 1.5A, and that should give us about 16 hours of running time. As these are not deep cycle batteries I would not run them for more then 10 hours.
this is outragious stuff!,
this is outragious stuff!, im supprised the military aint contacted you for this kind of GPS locomotion 
Very good build, awsome design im pretty sure you have got allot more insperation where that came from to make the next node even more exciting :D, cant wait to see it
Awesome
This is badass, great job! 
In reference to the VDIP1 Module… that’s a fun one to play with. lol I had alot of problems myself, had to use someone elses code to be able to use it reliably. I know it’s all good and long done by now but for future reference
http://openenergymonitor.org/emon/node/44
http://openenergymonitor.org/emon/sites/default/files/SAusbmemory.tar.gz
Bottom link is the .pde files. This is just a “demo” so the data being copied is the “supposed sensors” you should have hooked up. Bit late but hey… better late than never, some how?
