UHF radio control for submarines (openLRS, LoRa, FSK etc. on 458Mhz and 433Mhz )

No John it is not only you, three of the four vidoes also ask for Google when I also tried unsuccessfully to view?

With the 433mhz system will you be able to stop interaction between two seperate users?

Dave J

Previous I have done also a little researched from my side:

In Belgium the 433MHz is used for all kinds of remotes (cars locks, alarm systems, Garage doors,....).
A continuous broadcast of the signal is not allowed...... only data "burst" technology is allowed, so that all these systems do not interfere with each other.

Also the frequency is part of the frequencies used by the Belgian Amateur Radio Society, if you want to transmit within there allocated range you have to possess a license issued by the Belgian authorities. Everybody can obtain it after passing an exam about 25 Eur, and a practicum with a recognized Radio Society.

The more I read about I become convinced that the interference will be huge en it will be illegal in Belgium to use it.
So for the moment I will keep way clear from the 433 MHz stuff.

Please note that the a.m. is only valid for Belgium other EU members may have other regulations......still some work ahead for Europe I guess.

Another option for me is to migrate to the US or UK when the 40Mhz will extinct.

grtz,
Bart

Sorry guys, Youtube was "waiting for improvements" for some reason!

I hope that has fixed it.

Yes, Dave it should be able to enable a number of simultaneous users. It uses random frequency hopping like 2.4 Ghz systems.

Yes, Bart , 433 seems less than ideal but 459 IS a legitimate r/c channel in the UK. (Increasingly used by quadcopters etc. for flying ranges of several miles - hence the availabilty of the hardware.) And yes, a bit of European "harmonisation" would help manufacturers (and modellers!)

Hope the videos prove something (and they are now working!)

David

If you look at the 4 links. One says "watch" in the URL and the others say "edit".

Thanks Tom. I have re-posted the links in the original post and I hope that has fixed it.

I would like to say that you have missed a lot, but strange to say, videos of technology working very well is slightly boring! (Disasters make for more exciting viewing!)

David

Well a further update on UHF (400Mhz).

You can perhaps say that my inability to post a Youtube video correctly means that I am the perfect candidate to test this technology i.e if I can do it, you certainly can!

After a couple of hours work I have successfully "burned" the openLRS software in the TX module and the receiver and set it to the more legal 458/459Mhz frequency for the UK. The Charlie class is now working again "on the bench". (It  will have to wait for another 2 weeks for a pond test.)

So I can't see any reason why those interested don't think about ordering some gear and having a go - the stuff is relatively cheap so low risk. I bought the gear too and my second receiver is now on order so that you can see I'm also sharing the risk, with no "freebies"!

My shopping list was: (I've added more detail in the latest edit following an enquiry by Davidf J)

1x #9171000147/27096 OrangeRx Open LRS 433MHz 9Ch Receiver = $19.95
1x #9171000270-0/40032 OrangeRX Open LRS 433MHz Transmitter 100mW (compatible with Futaba radio) = $19.99

http://www.hobbyking.co.uk/hobbyking/store/__40032__OrangeRX_Open_LRS_433MHz_Transmitter_100mW_compatible_with_Futaba_radio_.html

1 x FTDI Basic Breakout Board 3.3v (DEV-09873) (From Sparkfun)         $14.95

The last item is the RS232 "Dongle" which plugs into the 6 pins on both the TX and RX. The other end goes into the USB port on a PC. I believe this is a standard board used with Arduino devices but do get the 3.3 volt version. The 5v version can burn out the RF (radio frequency) chip in the modules.

I am now just going to give my own experiences based on the video on Tim's excellent thread on SubCommittee. Look at the whole video first.

A couple of health warnings first:

- Always leave the aerials/antennae in place on both TX and RX. They BOTH transmit and you can damage the RF chip if you don't.

- Probably best to get the 3.3 v board as above. The video covers using a 5v version but it makes the process more complicated (and risky).

The outline of the whole process is:

- On your PC install the Chrome Browser and the openLRS app. (This was a new method of installing software to me but it worked faultlessly and I am using Vista on my PC (Don't laugh!)

- You will only get the basic menu screen up at this point. (You need to plug in the devices to get the detailed menus.)

- You need to have access to the 6 pins for the Dongle and you need to identify the dtr pin of these 6. You will find dtr printed on the printed circuit boards. On the RX board you need to peel back the plastic sheathing a little to see it. On the TX module you need to take it out of its plastic box. I cut a small slot in the plastic case so I could plug the Dongle in with the module in the case. By the way dtr stands for Data Terminal Ready which perhaps gives you a clue to how long the rs232 standard has been with us!

- Flash the RX first  (as per the video). Plug the Dongle in with the dtr pins coinciding. Select the button on the menu. The loading only take  a few seconds and the menu tells you what is happening.

- Again as per the video, Flash the TX module. (You will find it simpler with the 3.3 volt Dongle than the video - just plug it in (dtr to dtr)

- Now you get onto the more interesting part. Setting up the devices. I got into a slight wrangle with the instructions for binding the TX and RX but just remember that you are not doing any damage and that it will all work out in the end.

- You are then presented with quite a detailed menu screen for TX setup. On the left column, type in a new frequency between 458.5 and 459.5 (UK surface users are recommended to use frequencies below 459.1) This link has useful info on UK frequencies:  

http://www.ukrcc.org/  

-Turn Telemetry off (more on this in a moment).

On the right column you can select the number of frequency hops and how they are selected. (I chose 6 and random.)

- I didn't change anything on the RX menu.

- As a hint of how clever this system is you will see that there is a button which carries out a frequency scan. Another button displays your frequency hops.

- A bit more binding and unplugging and you should have the system working.

However, I was faced with a whole lot of jittering servos and limited response to controls. Half an hour of anguish followed before I realised that Telemetry was ON and this was creating interference. I later re-checked the video advice and I had missed that point!

My thanks again to Tim S and the SubCommittee for spotting and developing this technology.

This COULD be the answer to the equipment problems facing the r/c subs fraternity. The more openLRS equipment you all buy the more likely they are to continue manufacturing it. Continuity of supply is probaby the key issue in the ultimate success of this technology.

It would seem to have significant advantages over 40 Mhz technology and so maybe more second hand 40Mhz gear will also re-enter the market.

All good news for folks wanting to enter the r/c subs hobby!

If you use and like the software (and I do) please consider making a donation to the open source enthusiasts who created it. (You will see a PayPal button on the menu.)

David

P.S The next thing I need to look at is improving the aerials for use in subs at this frequency. I have just put an order for a better TX aerial into one UK based supplier of openLRS equipment:

http://www.flytron.com/

I will let you know how I get on.

Well the first photo tells the story. A sub in the far distance just beyond the mooring buoy.That is the Charlie sub using the Orange receiver on the legal, in the UK, band of 458/459Mhz band using openLRS.

So very good control even at long range.

I then moved onto doing some dives. All was fine until I tried some rapid dives (all out on the piston tank!) I overpressured the hull and the two hull halves parted company at the O ring seal!

Oh well, s*** happens with model subs!

We have a good set of waders at Barrow but the expression on my face seems to indicate that the pond level is good and high (cold water and above my waders!) My thanks to Dave J for the photo.



But the important thing is that there were no problems with the openLRS equipment and so we have seem to have a new, legal band for r/c subs in the UK. (We have also been in touch with the radio regulatory bodies in the UK, to confirm this, and we will report that separately.)

So I can't see any reason for people not to have a go with this technology.

Some more information, I ordered some better aerials from Flytron and the order worked very well. So if you want a UK based supplier of this equipment (I think that they have developed a lot of it.) then order away. (They seem to have an order backlog just at the moment.)

The next thing to test out is the "lost model" feature of the openLRS software. (It will transmit a beacon signal on the "walkie talkie " frequency of 446 Mhz.) I have some on order - the idea is that if a 458 Mhz signal can get down to the sub then a 446Mhz signal MAY get back up from the sub.

Particularly when  used in combination with Pinger and hydrophone, a short range system with directionality would be very useful for model location and recovery.

Finally the aftermath of the sinking does not seem to be too serious. Everything except my "waterproof" Mtroniks ESC has been dried and coaxed back to life. (Later edit: The Mtroniks is fine actually!) The Orange receiver is as good as new. Modern receivers like this one, don't have things like inductors and trimmers which are tricky to dry out. It is just chips and other surface mount devices.

Nigel has just been in touch about this technology (he is planning to have a go with it) and he suggested that I make it  clear that you use standard transmitters with plug in modules (I just plug in the Orange TX module in the back of my Futaba transmitter.) So it is really that simple.

Tim Senecal in his original article on the SubCommittee Forum takes you through other transmitter options.

Bring and Buy at Heywood this Sunday.

So what makes of transmitter should I be looking for that take these modules ??

david f wrote:
...I thought that increasing the frequency tenfold from 40Mhz could only mean no water penetration but those "data packets" just get through! It is also frequency hopping so model submariners will also enjoy operating without the dreaded (and argument provoking!) frequency peg board....


David

Hi David,
it is interesting to read about your successful experiments on 433MHz.
Of course there is no doubt that a 433MHz Signal suffers more attenuation in water than a Signal on 40MHz but as the wavelength on 433MHz is only about a tenth (approx. 70cm in air) your antennas are more effective and this can partly compensate the higher attenuation.
So this frequency band may offer an alternative in the UK if the 40MHz should be cancelled sometimes...
In Germany 433MHz had been used in the past but today it is no more legal for RC. I know that some submarine modellers have had 433MHz RC sets used in those days.

Kind regards
Klaus-Dieter

Hi Both,

John - I can only speak for my own Futaba T9CAP transmitter which takes the Orange TX module, I detailed earlier.

Tim S in the SubCommittee thread recommends a TX which represents very good value. (You need to buy an openLRS module also)

http://www.hobbyking.com/hobbyking/store/__31544__Turnigy_9XR_Transmitter_Mode_2_No_Module_.html

That may be the way to go if you don't have any suitable TX's which take a module. (I know from Dave J that he is also trying to find suitable modules.) Let us know how you get on.

Klaus-Dieter - You raise the very interesting point about aerial efficiencies.

In some ways this 400Mhz technology should not work! But it seems to be Data Packet technology combined with the ability to channel hop and (as you say) aerial efficiency.

We seem to be lucky in the UK to have the 458/459 band available for r/c. The openLRS software seems to have a wide tuning range (400-460Mhz??). Do regulations in Germany have a band available somewhere in between? In which case, you can try it.

David

Hi David,
it' s a sad story to tell that the permission for Radio control on 433MHz was cancelled at the end of 2008, and there is no other frequency in this range as Substitute. So 27MHz and 40MHz will remain the only frequency bands for model submariners in Germany. As long as these remain legal it's not a problem for me and those who have already 40MHz RC sets, but for newcomers it will be more and more a problem when less second hand RC-sets will be available on the market.
So you can be lucky in the UK for your new gained alternative.

Kind regards
Klaus-Dieter

Well in some ways that may be an advantage, since if Germany has no alternative then you may continue to sell 40Mhz sets. Germany must be a bigger market than the UK.

So some hope for 40Mhz equipment sourced from you?

On the other hand I have heard that Robbe has filed for bankruptcy, which can't be good news.

David

PS It does seem sad that 433Mhz was taken away in Germany. For car key and the like, I suppose.

Oddly I was testing the frequency scan feature for openLRS with David J. My Skoda key triggered a spike at 433Mhz. His BMW car key registered nothing between 400 and 460Mhz!

Hi David,
the 433MHz band is a band for so called ISM Equipment (Industrial, Scientific and Medical) and in this scope also radio control with so called low power devices with a maximum transmitting power of 10mW are still legal, so remote car key control may be used and other applications for closer distances. But in former days 500mW transmitting power was permitted for model Radio control and that was cancelled. I think 10mW would be too low in practice for submarine purpose.

Maybe you will find a little more 40MHz equipment on the German ebay platform but I am not so sure.

And as I know obviously most of the German model companies do not have 40MHz RC sets in their program any more.
Even worse - the two biggest companies, Graupner and Robbe, had got severe financial difficulties. Graupner went bankrupt about one or two years ago and was bought eventually by that Korean Company SC that made the RC sets for Graupner. Today Graupner is not the same as it was as the equipment for model production had to be sold. And actually Robbe has also difficulties. Perhaps the withdrawal of the model submarine kits by Robbe was a first indicator for upcoming financial problems. We must see how the story will go on.

The key problem in my opinion is the lack of young people following us "old men" in our Hobby - so one day the market will become too small for several big model companies. In my youth that is more than 40 years ago modelling was of very great interest among my friends at School, our favorite literature in the breaks were the catalogues of Graupner, Robbe, Hegi, Engel, AeroNaut ..... And in every mid sized town you could find a model shop or at least a toy shop with a model department. And today?

Kind regards
Klaus-Dieter

Hi all,

I thought i would introduce myself...   Tim Senecal, from Arvada, Colorado, USA.  :)

I was pointed at this thread via the posting that David F put on model boat mayhem.  I am happy to hear that the 433/459mhz stuff appears to be working well for you.

i simply wanted to add that most of my current posting on this topic is being done at

subpirates.com

specifically in the technology section


it appears i am not able to post links for a few more days, so i will add links later if you would like.


I have been working on two fronts as far as 433 stuff goes...

1) much like David, i feel that the antennas that the devices come with are pretty low-end, and have been buying and building/testing new ones.   All the FPV guys are raving about a $30 antenna called the "Nagoya NA-771".  so i bought one, and i feel making my own is both less expensive, and better performing.   I have made several half-wave and quarter-wave antennas, and find my home made quarter-wave work well. in addition, since you guys in the UK are not actually running at 433mhz, i think you will probably have to make your own antennas if you want them tuned correctly for 458/459mhz... that is a small difference, but it ends up being about 1/2" or 1cm difference in length of a quarter-wave antenna. I have basically been using the online antenna calculators, and using the lengths indicated. I have not been adjusting for water. don't know if that helps you any.

2) telemetry.  i bought a bunch of the FrSky telemetry Hubs (FSH-01), and have wired up harnesses to allow me to connect them to the 433mhz receivers, as well as harnesses that allow me to connect the FrSky display (FLD-02) to the transmitter module.   I am now getting battery voltage, amperage, temperature, and signal strength.   soon i will be adding motor rpms and ultimately depth.   activating the telemetry gives me very simple signal strength readings - "RSSI", which have improved my ability to make my own antennas.

as to what Hermann says, I did some investigation earlier... I believe that Germany has the strictest rules of all euro nations, and 433 specifically resides within 3 different areas of regulation.   LPD433, ISM, and CEPT - "European Conference of Postal and Telecommunications Administrations",  which is basically the European equivalent of the US's  HAM....   but stricter.   IF you have a CEPT license (and not a novice license, but a full license) you will be able to use the full 1watt 433mhz systems.  but only if you have the CEPT license.  

as to the ISM 10mw output limit...   i know the HopeRF module the 433 systems use has power output settings, and the Chrome Configurator allows you to set them.  level 3 on a 100mw system would actually be outputting 6-7mw...  Testing at that level to see what amount of penetration it gives is certainly possible.  interesting enough, the HopeRF module these use was designed for use in ISM equipment.

Welcome Tim!
I call Tim the Mad Scientist (hope you do not mind me sharing that). He has a passion for this hobby and the gifting to be a game changer for our submarine addiction plus he is just a genuinely nice guy.

Look forward to more details on what you are working on.
Peace,
Tom

Very nice of you to look in, Tim!

I hadn't spotted your postings on SubPirates - I will be glued to it for your next installment. Very pleasing  that the telemetry works so well. Also a very interesting idea to use the signal strength feature to optimize the antenna configuration.

Thanks again for identifying and developing the use of this technology. It could have all sorts of benefits for the sub community.

David

Videos in Technorama and "Davevision"!

Well probably not THE most exciting things you will see on Youtube but they the latest trials of openLRS system on 458Mhz with a r/c submarine at Barrow in Furness. Beeping is telemetry signal returning from sub i.e lost return signal.

This is using the simple 328mm long whip antenna suggested by Tim S in the antenna thread.


https://youtu.be/QW8IV-k10Kg

https://youtu.be/OzxR7GbEVuc

https://youtu.be/7ZWRD5Fc37E

https://youtu.be/vujkwBSzwvc

https://youtu.be/hbj_3xSKO18

https://youtu.be/nEHhHNmbTsI

The telemetry return signal introduces a new dimension to the hobby because you can continuously monitor the model. (In one video I am surprised to find that the model has surfaced!)

I was hoping to test the quarter wave aerial but didn't have the time. The half wave  fits quite well into my WTC and presumably is more efficient anyway.

I was hoping to test the lost model beacon signal via a walkie-talkie but, for some reason, the receiver software changed the beacon signal channel from the one I was listening on! (So maybe best to treat the software as a work in progress.)

But overall I am very pleased with the new technology introduced by Tim S. No going back to long aerials on 40 MHz for me!

David

The sailing trials are impressive and I thought the telemetry feedback was an interesting new dimension on performance.
Very good David.

when you say 328mm whip antenna, is that on both the TX and RX?  perhaps a picture or two?

Hi Tim,

Some photos, as requested:




From the top this shows the Orange RX with the shortest antennae I have made (Untested in a sub.)

The next one down is the 328mm whip (Tested in the videos.)

This was used with the bought in TX antennae shown. This was bought from:


http://www.flytron.com/15-antennas-filters

3dBi 433Mhz UHF Antenna (right angle)

This is labelled as 433Mhz and so is probably less than ideal for 458 but it seems the only one easily available. (I wanted to have a short TX aerial for cosmetic, ease of use reasons!)

  I also bought a couple of these adaptors from Flytron because they can be used to make your own aerials by soldering a wire on.
 

  SMA Male to SMA Male Adapter


Finally here are the innards of the aerial which comes with the Orange equipment. It is OK really and you can see that it has a loading coil. I suppose the thing against these antennae is that they are designed to minimize length - which is not THAT important for the RX aerial on a sub.




Nigel suggests that with the telemetry use, it is just a question of trying a long antennae and just snipping bits off until you get the best results! And that is about right.

The only other variable seems to be the aerial orientation. A vertical aerial could be used but the paper by Butler seems to suggest that a horizontal aerial is best because the radio signal is refracted at the surface anyway. Also the use of a ground plane seems to get a lot of discussion with the flying fraternity. I don't know if it is relevant in subs.

(BTW sorry I started a new thread on antennae because the whole topic is perhaps best dealt with in one place. I will put the link in for completeness:
https://www.theassociationofmodelsubmariners.com/t1529-aerials-antennae-for-458-459mhz#9388
)

David

David,

yep,  looks basically like what i am doing.

here are two of my receivers, both with homemade antennas, one solid, one floppy.



i bought the SMA connectors off of ebay, a 10 pack was roughly $10.00, i bought a set of straight, and a set of 90 degree.

here are a few more:



basically two quarter-wave, and two half-wave ( ~160mm and ~320mm )



finally,

here is a photo of my telemetry display.   it was two numbers and bars at the bottom of the display that are the RSSI values.  Just like Nigel says, i start with a long antenna, and chop off 1mm increments until the value on the left stops going up.




i did a little testing using this RSSI display,  i tried the original antennas that came with the OrangeRX stuff, a nagoya 701, a nagoya 771, and the home-made antennas.   the nagoya NA-701 was $10, the nagoya NA-771 was $30, and the home-made cost about $2.00 each.   of the bunch, the NA-701 had the best RSSI value, and the home-made were within 5 points of it.  interestingly, and the reason i decided to make my own, was the $30 NA-771 was no better than the original crap ones from OrangeRX.  after more analysis, I had bought a "cheap" clone, and not a real "nagoya NA-771" as advertised.  it is almost impossible to know if you are buying a real, top of the line antenna, or a knock-off, until you actually have it in your hands.

sadly (or maybe not), the 701 and 771 are not available for 458mhz, only 433.

David,

the FrSky FLD-02 telemetry display is available at www.giantshark.co.uk (£24), and much cheaper at hobbyking ($20). I highly recommend getting it, if for nothing other than the RSSI values.

with the addition of one more $3 part, (FBVS-01) you can get the voltage of your primary battery pack sent back as well. the signal strength indicator, the RX battery value, and the main battery value are really nice to have.

In a couple days (this weekend) i will be soldering up a new cable to go on my new transmitter with my second display, i will be posting that on subpirates.

Thanks for the suggestion about the FrSky display module, Tim, that would help a lot in optimizing antennae. I take it that this module using your simple interface could plug into the Orange module in my Futaba TX? (I need to read more of your write-up on SubPirates too.)

Yesterday's experiments were at a new (very nice, local, and clear) pond courtesy of Windermere model boat club.

The aims were to test a quarter wave antenna and to see if the lost model feature of openLRS works. (The transmission of a tone on 446Mhz PMR band (in the UK) which can be picked up by a ordinary walkie talkie.)

I was only using transmitter beeping to indicate signal strength but it was very noticeable that the half wave aerial (328mm long) gave much better range. I could only just control out to the left hand headland with the people on it, with the quarter wave aerial.












The last photo shows the Charlie class weighted down with lead in about 2 feet of water. (Follow the line out from the reel!)

My Motorola walkie talkie could pick up the lost signal tone (The Close Encounters theme!) from up to 100 yards away.

This came as a very pleasant surprise! It means that another method of locating lost subs becomes available. It would only survive for as long as the sub battery (unlike a self contained Pinger type audio device.) But it may provide more directional information than audio Pingers and it may do this in deep water?

So wow - another potential benefit for subs opens up!

It is also very pleasing that another club member David J is taking the plunge into 458Mhz. The more the merrier!

David,

first, let me say that the pond you were at looks like a great place for model subs.

next, yes, i have cut slots in both my 100mw OrangeRX openlrsng futaba module, and in my 1watt Hawkeye futaba module.  the display works equally well for either module.  the slots were originally cut so that i could program the modules without taking them apart.  the same pins used to program the modules are the pins used to recieve and transmit telemetry data.

because the display is designed for a slightly different protocol, a special cable needs to be made for it to work with the openlrsng modules instead of the FrSky modules.  I had made two of those cables for my Futaba 9cap radios.  I have since sold those two radios, and replaced them with Robbe FC-28s.  one of the cables for the 9c is too short for the Robbe.  i need to make a new one.






i have also made cables that allow me to connect the FrSky telemetry hub to the openlrsng receivers in two of my submarines.  making those cables is documented in the telemetry thread on subpirates. hopefully, the new TX -> display cable will be on that same thread sometime this weekend.


finally,  it is great to hear that the beacon feature works.  I had never even thought of using that feature.  I am curious how deep the submarine can be before the handheld no longer is capable of getting the signal.