what about RF remote controls for servos an data transmission?

Im afraid i can be of no help... other thant to say

there is not much wrong with your english, infact it is very good., better than some of what i see in other groups anyway

You're unlikely to find an off-the-shelf gadget that does all of the above, cheaply.

What skills do you have - can you write software? If so, you could get a small embedded micro (or even a mini-ITX motherboard PC running your favourite OS) and rig everything up to it (control servos from the parallel port, and have a serial port) inside the boat, then attach a wireless ethernet card (I *think* that can do that kind of distance) or an ISM band serial transceiver and talk to it from your laptop?

I gather from your tone that you don't fancy the idea of designing your own control systems that use an ISM band transceiver module hooked up to logic that handle your servos and seperate serial channel?

ABS

Hello Alanic thanks for taking time to answer. my skills are mainly structural. electrical skills are very little. i would like to make something on my own, but i dont know where to start from.

i was thinking about using a wifi solution, but the range of most cards is limited, i would need a card that has some kind of high gain antenna, and then i would need to upgrade also somehow the recieving card to boost up range. it would be indeed the best solution, to put a small mb with everything on it on the boat and send it over wifi. but how do i get a range of

300-500meters?(at least it would be in open air :-) ) where could i find information on programming servo passing tru serial or paralel port?

thank u for the info!

mat

Making it yourself is fun, and cheaper ;-)

Hmmm... What range do normal commercial remote-control-model controllers have? You could use one of those to control the servos, and I'm wondering if you could figure something out to do low-baud-rate serial over it, too. I've heard of controllers with on/off channels for controlling lights etc. With a little bit of electronics (or maybe none; RS232 is quite forgiving) you could drill a hole in your controller to pass in the TXD line from the laptop's serial port and use it to drive a switch, and then embed a controller in the boat itself likewise modified to send the RXD line back (on another frequency) to a received hooked up to the laptop...

Yeah! You could play with making it autonomous, too. Radio reception down? Then navigate back to the launching point by GPS ;-)

I'm not sure what the maximum range of wifi is, but I know you can make the famous "pringle-can antenna" to make it directional; from the laptop end, you could use a directional antenna to track the boat, and a normal one in the boat.

Ahah! That depends on your OS. But the parallel printer port on a PC is basically about ten digital output lines, which can (via commercially available relay, opto-isolated-transistor, or dedicated servo-controller boards) drive the inputs of servos.

;-)

ABS

Matthias,

Maybe the people here can help you:

(English and Dutch forum)

I'm a bit lost here: a Dutch name, Italian e-mail address, English newsgroup ;-) ???

Met vriendelijke groet ;-) Ron van Sommeren near Nijmegen, the Netherlands

Sounds likes a water borne cruise missile to me!

I did some work on a full size hydro, logging engine rpm and air speed etc. Biggest problem was engine ignition interference (six cyl Chevy tuned to

750BHP). I did start to think about live data link back to shore, but the cost of an off the shelf data link didn't warrant the benefit, so we just stored the data on board and dumped to a laptop at the jetty after each run.

A long winded way of saying avoid on board things that generate electric noise, catamarn sounds sedate so would assume that you are still in the glo motor sort of engine size, say 10cc or so? It might even be a good srategy to start with glo motors and get the system robust before using some nasty 2 strokes.

Steve

and bigger faster and with more options... i like the biggerpart...it makes it available for nice toys like gps, cameras and, with twinengine it should be capable of pulling a nice weight.

yes indeed, that would be a very nice feature, and let it navigato to waypoints... i have some ultrasonic sensors laying around...with an onboard pc i could play a lot, must learn some computerlanguage ... any suggestions on what would be easiest to start with? visualbasic? others? i found a few mb with onboard cpu for less then 100euro. some ram is always laying around, just would need a small hard disk and wifisolution...

wifi can have various ranges, heard about 6km...but i cannot spend 1000euro on just the wifi part...on the mb of the boat i could place a wifi pci card with changable antenna and put a good one... ho can i put a directiona antena on an integrated wifi laptop....i would need somethin like usb with again changable antena...ill look for that. what is a pringlecan antenna?

yes i have seen them around. i will have to look into it...i saw some serial boards that can control 4 servos...i will look for paralel stuff..

wifi and microatx would be the best solution maybe, cause it would be easy to control it with a remote desktop program, and i would have to setup a stupid streaming server to get the images back on my laptop,but with most progs i would be delayed (the video stream) so i must look around for that.

keep on bringing in the ideas! i like this newsgroup stuf.... first timer for me.

have a nice day.matthias

the plan is to build it large scale. 3 meters length i dont know yet what kind of engins i would like to use, but i was pointing on two engines each of 35cc 4 stroke . i have made a lot of models with electric engines...but since i have a house on a greek island i would like to jump the "middle class" and start with big project. the data link would be necessary to have control on at least 4 servos at a range of 300-500meters...Mr. Alanic here suggested it would be easier to put a motherboard with all on the boat an use a wifi connection to send it to my laptop...boh... u think interference would be to much?

mat

its what u get with the f**cking eurean union! ehehe

ik zal een kijken op de forum ... thankS!

met vriendelijke groet (with friendly greetings)

Matthias, actually in brussels, erasmus for thesis in eindhoven, student of La Sapienza (roma), with project for Zante (greece).

:-)

I couldn't say - all I know is that the electrical noise from the ignition systems needs carefull consideration. An easy way is to prototype the electronics on the bench, then stick a four stroke motor ignition along side and see if it still works fine. WiFi sounds a great idea.

Steve

Have a look at

for transmitters.

On the boat I would use a embedded PC, somthing like

and run WinCE (insert OS of choice here). If you add a cheap handheld GPS that allows external antennas and a serial link that speaks NMEA you can hook that up via serial to the PC and know where you are. PC-104 form factor is nice as there are a lot of industrial add on modules such as relays and motor controllers As suggested else where, if you lose the link back to the base station, then having the ability to sail home would be very usefull.

As for the base station on the shore, any laptop with a serial port should do, also get your reciving antenna high up of the ground, so it always has a good line of sight to the model.

Your not going to do this without quite a bit of programming know how to get all the bits to work together. I suggested WinCE above as it is free for personal use and allows you to use some higher level languages such as VB/C# if you do not want to get into C/C++

Stephen.

See/ask also: news:alt.engineering.electrical news:nl.hobby.elektronica (only for very intelligent, i.e. Dutch, people ;-)

Met vriendelijke groet ;-) Ron van Sommeren near Nijmegen, the Netherlands

work?links

i printed out ur mail! looks very interesting. i was indeed discovering that i will need to learn some programing stuff... but i found also a lot of examples for scripts to control servo with serial connections.

thanks a lot! matthias

but, i was looking at the options here... thing is, if i take a miniatx motherboard with embeded cpu i can create a relativly very powerfull computer with large storagecapacity and same if not more connection options... the fact that this would be a bigger in size solution would be no problem as the catamaran is in big scale, it would be way cheaper... the only thing would be how much power would such a system use, and can i take the power from battery (anyway needed for a lot of other stuff that will be onboard) ? i dont need an autonomy of 10 days, i would be happy with 1 hour lifetime of battery. but very nice the board you suggested, it is indeed very tempting.

If you go for a standard board like the Mini-ITX you will need supply +-5V

+-12V, where as an embedded board only needs +5V. Also you can boot them from compact flash and thats one less thing to get wet/broken (i.e no hard disk).

Keep us up to date with your progress!

Stephen.

interface....

well i have build allready lightweight containers for my gps loging...i would use that anyway...and i was thinking to use a laptopharddisk for shockproof and lower consumption of power. the 5 and 12 volt need to be very steady dont they for the minatx? and how much power would that drain...what kind of batterys should i be shipping? i yet have to calculate the weight i will be able to load (engines, pc, fuel, batteries) but i assume it will be around 50 kg, that should be enough... later i will try to graduatly lower the weight for parts...but that would be after testing in slow heavyweight conditions.. :-)

have a nice evening.matthias

message

You might be able to reduce the cost a lot by using an embedded board with FORTH on - that will also save you from having to learn VB/C#/C/C++. FORTH is pretty handy for developing embedded software, since you can use it as a command prompt to test stuff out via a serial link as well as writing "stored" programs, and it has very very low system requirements.

If you can wait a few more months, I'm working on building (and selling to folks) a little embedded controller with a FORTH system and a range of plugin modules for serial ports, servos, etc. selling in the UKP50 region! It would measure about 50x10x10mm and consume negligible power...

ABS

Are you in the UK, physically? I'm a freelance software engineer trying to learn hardware engineering by experimenting, so I'd happily write software for you if you showed me how to build things in return ;-)

ABS

For learning - particularly in controlling hardware - it's very useful to go for a language that can run with a command prompt, like traditional BASIC, Python, FORTH, Lisp/Scheme, etc.

The reason? Because with C#/C/C++ and friends, you need to write a program, compile it, download it to the embedded system, and run it. If you're testing stuff like servo control out, you need to keep adjusting the program and running through the cycle to try out different versions, or invest extra effort making your program let you tweak it as it runs.

With an interactive language, however, you can type commands in and have them run right before your eyes, which saves a lot of time and frustration. And it's fun, you can use it as a control interface for your finished system, so you don't need to write a user interface.

Cool! :-)

Ahah:

It's wonderful fun to share one's ideas online and get people's input! I enjoy helping out, too. I'm much better at *planning* projects than

*doing* them myself ;-)

ABS