Thank you for your comments.
Even if the boat is working good now I still want to make it better so I ordered a FEZ Domino from Sparkfun http://www.sparkfun.com/commerce/product_info.php?products_id=9797
I’m accustom to the Microsoft visual studio and the .NET framework so this can be exiting.
Arduino is fine for things not involving string manipulation or file IO, so I’m looking forward to write real managed code in C# and a proper file system.
Hi Geir, what kind of motor
Hi Geir, what kind of motor and propsize do you use? 1.5A seems little to me, is it running at top speed with 3km/u? And the batteries 12ah in such a small package?
The motor I’m using is a
The motor I’m using is a cheap eBay motor 12V and 1000RPM.
http://cgi.ebay.com/2-x-12V-DC-1000RPM-Mini-Torque-Gear-Box-Motor-Hobby-/320569452420?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item4aa36da784
These are not brushless racing RC motors but geared high torque motors.
It actually draws less then 1A but the other equipment also draws some current.
The propeller is a 70mm. Can’t remember the pitch or the maker, but it’s a standard RC boat propeller.
And these are the batteries http://www.biltema.no/no/Bil—MC/Elektrisk/Batteri/Blybatterier/ number 80412.
So it all adds up 
I took it out for a run this evening and it had an average speed of 3,3km/h with a top speed of 3,64km/h
Don’t worry I trust you, I
Don’t worry I trust you, I just went over this topic a few times and it makes me think about things. I ordered some solarcells from parallax to play with. With a 50 watt solar panel (2,5 kilos, waterproof) and a pile of lifepo4’s you possibly have unlimited reach at no weight gain. Well, at sunny days that is.
Did you test with different props or just this one?
The propeller I’ve got is
The propeller I’ve got is a 2 blade. I tested a 3 blade with the same size but it made no difference. According to the hull/speed calculator the maximum speed for this boat as a displacement boat is about 3km/h http://www.psychosnail.com/BoatSpeedCalculator.aspx
As we are going for distance and not speed, the current speed is perfect for this job.
The original plan was a catamaran with solar panels but as long as this boat performs as good as it does, -that’s somewhere in the future. I would like some other batteries as the boat sits a bit deep in the water, but for now, its ok.
Are your happy with your DST800 echo sounder ?
Geir, I’m working on a similar project as yours. In some words I want to survey surf spot reefs to understand better the mechanics that make the waves break (and bottom is very important for the shape of the waves). All this using a robot, of course!
You are using the airmar sounder DST 800. Does it give good result, and in particular is it accurate? For the same price Airmar proposes also P79. In the datasheet P79 is more accurate (less wide beam) but does not send temperature and speed. So the choice is not easy more me.
Do you think, after use, that DST800 is accurate enough to clearly detect and map isolated rocks, for example?
Thanks for your thoughts!
I must admit that I have
I must admit that I have never manually tested the accuracy of the transducer. For our project we don’t need accuracy down to the cm as the goal is to get a contour map off the seafloor and calculate the volume of the lake. I think the target marked for DTS800 is small boats that need information on the keel dept and not for detail mapping. If you need accurate information on large rocks on the seafloor you probably need a side-scanner, but that is in a complete different price range altogether.
When it comes to temperature and speed you could probably just add a temperature probe and the speed is available from GPS information.
Multibeam sounder are very
Multibeam sounder are very expensive as you say, and completly out of my budget, even if of course it would create incredible results in a ridiculous short time!
> “the speed is available from GPS information”.
GPS gives ground speed. I thought DST800 was providing surface speed, but after all I don’t know, you make me think I was maybe wrong. Anyway, surface speed is important to compute drift. You are working in lakes I think, so you don’t care about drift, but I have to care of it since I’ll work in the ocean where tide currents can be important.
Did you have some bad surprises to connect DST800 to your arduino? Did you find a way to use the Airmar plug (I think it is a special 5 pins plug), or did you cut the cable and solder directly to your system?
You’re probably right in
You’re probably right in that the transducer gives you surface speed as it has a small impeller that gives you the speed in normal NMEA sentences. And as you say the speed is of no importance to us. It’s fun to know when regarding mission calculations but for the logging part it’s of no value.
When it comes to the cable plug, there is no plug with the system. It’s only bare wires so I cut the cable and added a 3-pin polarized plug of my own. I do believe it’s a regular TTL UART (that make sense as the supplied voltage is 5-24V), -but check the signal before you fire your microcontroller.
The way I did it was to hang the transducer in a bucket of water and checked the signal on a scope. You hear a faint clicking as the transducer fires. If the signal is within the TTL UART range, hook it up and decode the NMEA.
Garmin Transducer to get depth
Hi, I’m from Brazil and I have the sonar depth: Garmin fishfinder 160c ( http://buy.garmin.com/shop/shop.do?pID=292&ra=true ). I would know if could connect Transducer ( https://buy.garmin.com/shop/shop.do?pID=710 ) directly into the Arduino to get the NMEA signal or have to put all equipment?
What Transducer you recommend I buy?
Thank you for your attention and sorry for the poor english, Celso.
You need to find a digital
You need to find a digital transducer that will give you serial information on TTL or RS232 level. From that you can read the NMEA sentences.
I think both of your links are to analog transducers.
I haven’t been working on this for the last 3 years so I won’t be able to give you a good recommendation. Google for transducer and NMEA and you will probably find what you are looking for.
http://www.blueheronmarine.com/NMEA-0183-DST800-Transducer-Plastic-DST800PV-S-6422
Best of luck
Connect DST800 transducer to Arduino board ?
Hello Geir,
First of all, I must say that it’s a great pleasure to read you with the SEA RENDERING project. I am a very beginner with Arduino and electronic as well so what you explain makes me understand lot of things.
Of course I have a little question to ask : I don’t really understand how do you connect DST800 transducer to Arduino board ? Don’t you need a RS232 / TTL card between both of them ?
Someone say that it could burn the Arduino without RS232 /TTL card. Is it correct that you have tested the transducer before connecting the arduino so you were sure that there was no danger for the Arduino ?
Thank you very much for your answer
CW
HiThe transducer I used had
Hi
The transducer I used had a 12V input voltage but the communication was at TTL level. The RS232 signal is from +12V to -12V and TTL are 0-5V so I did verify that the communication out of the transducer was in the range 0-5V before I connected up to the Arduino.
So if you hold your transducer in a bucket of water and measure the voltage out on the serial line and it’s in the 5V range your good to go.
Dr. DEPTH
I’m a biologist at the University of Bologna in Italy and are interested in implementing a boat with operational capabilities similar to those of your project. In particular, the ship should be able to load my water samples to determine pH, dissolved oxygen and conductivity as well as other chemical and physical parameters. I have difficulty in finding sonar could tell me the model, the manufacturer and retailers of sonar used by you? I also have difficulty in obtaining a copy of the software Dr. Depth is no longer available on the official website. I am also available to purchase a trial copy of the program: you think it’s possible to do so pending the availability and distribution of the new program? If so could you send me a copy of the software? Or could you tell me alternative low-cost software that have features similar to those of Dr. Depth? Thank you in advance for availability and I look forward to your feedback or your email address where you can write directly.
Dr. DEPTH
I’m a biologist at the University of Bologna in Italy and are interested in implementing a boat with operational capabilities similar to those of your project. In particular, the ship should be able to load my water samples to determine pH, dissolved oxygen and conductivity as well as other chemical and physical parameters. I have difficulty in finding sonar could tell me the model, the manufacturer and retailers of sonar used by you? I also have difficulty in obtaining a copy of the software Dr. Depth is no longer available on the official website. I am also available to purchase a trial copy of the program: you think it’s possible to do so pending the availability and distribution of the new program? If so could you send me a copy of the software? Or could you tell me alternative low-cost software that have features similar to those of Dr. Depth? Thank you in advance for availability and I look forward to your feedback or your email address where you can write directly.
HiIt turns out that Dr.
Hi
It turns out that Dr. Depth has sold the software to Lakemaster http://www.johnsonoutdoors.com/uploadedFiles/Media/Press_Releases/LakeMaster/LakeMaster%20AutoChart.pdf
And there is some more information here http://www.lakemap.com/AutoChart/#.UfZXotU4Xct
You can find the transducer online http://www.blueheronmarine.com/Raymarine-DST800-Plastic-Transducer-DST800P-A-6588
But you could probably use any digital transducer that supplies NMEA183 data.
You can send me an email directly via my contact page.
Best of luck.
Waypoint data
hi,
you project is cool. i want to build one. can i get the format you save the data to SD. and a link for the planner software.
I just save the NMEA
I just save the NMEA sentences as they come from the GPS and transducer.
‘planner software’ ? what do you mean?
Waypoint data
what i mean is the waypoint planing and feeding to boat to run it. how do you do it.
OK. The waypoint software is
OK. The waypoint software is my version of the Arduipilot tool. It is written in C#
And if you put a post here on LMR of a working boat, I’ll send you a copy of the software.
