PINNED - Plug & Play PGDT for Radio Control

[woodygb]

Woody, Thanks for sharing, never knew those could do that kind of action, or of the different weight classes. That's fun!

As well as weight classes the FRA ( Fighting Robots Assoc ) have defined different classes of Arena construction.. a Class 1 Arena is required for Heavy Weight Spinners...however Class 2 Arenas are the top rating that we currently have ..this is due to construction cost and transportation logistics that the Event Organiser has to contend with .... so we don't / can't run spinners due to safety concerns.
http://www.fightingrobots.co.uk/content ... d-safety_1

India caught the Robot Wars bug ..maybe 6 years ago ......safety however doesn't appear to be high on the agenda... despite our warnings.

The first video is a close up of a pair of "Spinners" ... one drum and one bar ...fighting in a small Acrylic box.
https://www.youtube.com/watch?v=mKBqT-B2gM0

The second video shows the same fight but from the audience view point ..

WARNING!! ... Some people may find this second video distressing!
https://www.youtube.com/watch?v=qjxCX83Cr1Y

[Burgerman]

Well some steel mesh may be in order... That was too predictable.

https://www.google.com/search?q=steel+m ... =629&dpr=1

[Blade Runner]

Dr. Golu wins! And some poor kid loses.

Bob

[rustyjames]

Well some steel mesh may be in order... That was too predictable.

https://www.google.com/search?q=steel+m ... =629&dpr=1

Yes, that or some very thick Lexan.

[woodygb]

B.M.

Some questions about the Omni.

Can you remember if the Omni 9 pin plug wants a Joystick reference voltage of V/2 = 2.5v on pin 2 ...OR ...is it supplying a voltage of 2.5v ?

Also the 12v supply pins 7 & 9..is it 12v EXACTLY? ...and would you... or others want/need the ON/OFF that is available via the 3.5mm Jack plug ?

omni.png (20.72 KiB) Viewed 17673 times

[Burgerman]

This is from 2009 memory...

I didn't measure the 12v as I just used a voltage reg chip and a tiny cap to stop any ringing. To give me 5v. for rx and for tiny speed controllers. These were used for a low current signal. No smoothing. They work anyway.

I don't think I used the ref pin at all, and just used 2x forwards only 2amp speed controllers. These give a 5v swing so 2.5 in the centre. Swing reduced with resistor network, and tiny 20 turn trim pots to get accurate end points and an exact centre. Which turns out to be a few tenths of a volt higher than 2.5v...

The on off is used. I can drive the chair into the van, or garage and flick a switch to turn it off. For good. As this removes the rx power too. Add a separate rx battery, or supply, and you could turn it on again too.

[woodygb]

Cheers that means I don't have to worry about producing a voltage reference for the Omni.

I was considering using the 12v as a power supply ..but it maybe marginal @ 100mA... fine for just the Arduino board ( it has a small on board regulator that takes 12v MAX )... and a couple of led's but I'd like to power the R.C. receiver from the same source....so I'll keep with these that I bought from Ebay ...rather than tempt fate.



http://www.ebay.co.uk/itm/LM2596-DC-DC- ... 4179f1f1b8

[Burgerman]

Hope my memory was correct then!

[woodygb]

Hope my memory was correct then!

... Give me a little time and I'll send you an Arduino based thingy-me-bob for the Omni and you can find out.

[Burgerman]

So I plug in a spektrum RX and plug the gadget into the D connector? OK, I live in hope.

Does it basically do the same as my DIY version? Turn two channels into a 1.2v swing?

If so I know someone that wants one already... I cant face building another, too much fiddling about to get it to work safely and accurately.

[rustyjames]

I'd like to buy one too, Woody, if you're into doing and shipping it. And I'll probably buy one of those programming cables as well. I have a Qtronix controller/pod on my Quickie 626 and 646.

[woodygb]

HOPEFULLY ...It should be a case of plugging in the Aile and Ele of the RX and probably another channel for ON/OFF...currently it's Rudder.

If necessary set the transmitter to 100% throw with NO offsets or trims etc ...

Then turn on the Transmitter / Receiver/Arduino ...

Press a button on the Arduino board ...move the transmitter Joystick to it's extremes in vertical and horizontal ...this reads and writes the neutral and end point values to memory ... ( you have 10 seconds to do this and you can repeat the procedure at anytime if needed ).... then plug the 9 pin Din into the Omni and with a bit of luck the Gismo should control the chair.

Here's a pic showing the Serial output from the Arduino .
Programmed end points .... 2.5v centre with a 1.2v swing.. so 1.3v and 3.7v as the end points...
I currently have BOTH a R/C Transmitter and an old PGDT Analog Joystick inputting to the Arduino.

1.2v swingx.gif (227.97 KiB) Viewed 18110 times

[woodygb]

I'd like to buy one too, Woody, if you're into doing and shipping it. And I'll probably buy one of those programming cables as well. I have a Qtronix controller/pod on my Quickie 626 and 646.

The cable you can have straight away ....the Arduino interface may take some time as I'd like it both right and safe.

Have you got an Omni?

[rustyjames]

Not in any hurry, just another project amongst the many already started. Yes, I have an Omni. Thanks Woody.

[RC Hopeful]

I think rustyJames and I are in the same boat. I just purchased a used Omni from ebay, and is due to arrive tomorrow. I got it for $105 US$. I still have yet to find a spectrum for decent price, maybe they are not so common here, as their are alot of other brands for sale. The other cable software I was referring to is the Neutrik RS232 cable SA76525 and the PC programming software for it. It works great, I'll tell ya, you would really hate to be sitting in that thing at full turn speed and acceleration set to max. CRAZY fast.

Woody, and me to the list too!! Cant wait to see it in action.

[Burgerman]

ANY modern half decent 2.4ghz system, is OK. Futaba, Spektrum, JR, etc.

Even UHF systems, and 35, 40, 72mhz systems will also work in they are PCM or otherwise encoded and have a failsafe.

Failsafe is important or the chair can run away. It must stop when interference or loss of signal occurs.

[woodygb]

http://www.ebay.com/sch/i.html?_odkw=sp ... x&_sacat=0


If and when you decide to buy a transmitter ...be aware that there are two ( actually 4 exist ) different stick channel combo's or Modes.

http://www.rc-airplane-world.com/rc-tra ... modes.html

I use Mode2 and the RC Arduino will be fine on any stick combo.

[Burgerman]

Woody, can you configure the system so that you just plug in say 1 to 4 satellites only? As the helicopter flybarless systems do. No rx needed as such.

And also links to futaba http://www.ebay.com/sch/i.html?_odkw=fu ... 4&_sacat=0

JR http://www.ebay.com/sch/i.html?_odkw=fu ... 4&_sacat=0

These 3 are the big ones. Spektrum is a newcomer that took over for a while as they were first with 2.4ghz frequencies. Early spectrum stuff was a bit cheap and basic. Now they all are pretty similar. All will work. But its nice to have some adjustability, mixing, exponential, dead band adjustments, trim adjustments, rates, etc rather than just the basic sticks. So while the cheapest of cheap will work, it may be worth looking at some of the others.

And receiver's vary too... In failsafe capability, and in diversity and satellite rx additions.

A powerchair is not a good place for a 2.4ghz rc receiver. That's why I have 3 extra external receivers. For a VERY reliable 100 percent secure signal path in vans and around house and people. I don't want to watch it destroy my van/kitchen or mow down an old lady while waiting for the failsafe to kick in...

[woodygb]

You will need to educate me on that system ...never used or seen it!

The Arduino will accept a standard RC signal .... ( 3 signals in this case... 2 channel signals from one transmitter stick for driving and another for ON/OFF )....that is output from a receiver ... assuming that the Satellite system uses the same signal protocol ..then it should be 100% compatible.

[Burgerman]

http://www.spektrumrc.com/Products/Defa ... ID=SPM9646

This is a total DSM2 or DSMX receiver. My 10 channel receivers that I use for everything come with a built in receiver, and 2 satellites. It can take 3. So I add a third too.

It allows for signal diversity, covers null areas, and different polarisations. It drastically cuts down on radio connection loss.

The flybarless systems used in helis, use ONLY one to 3 of these. And some roboteq controllers only require these. They are tiny and work at 1024, 2048, support failsafe etc and DSM2 and DSMX.


http://www.spektrumrc.com/Products/Defa ... SPMAR10000 I use these - One at front of chair.
With 3 EXTRA satellite receiver's located one each side, and one high up in the backrest.

http://www.rchelicopterfun.com/flybarless.html FLYBAR LESS! Uses ONLY satellites on mine.

[Burgerman]

I use these.

Main receiver has an antenna.
3 additional equally sensitive recievers, allow you to put them in different planes (polarizations) and away from the structure or metal in a wheelchair.

I put the MAIN receiver at the front under the wheelchairs seat pan. This one gives the worst results. If used alone I get signal losses at various angles even in the next room 20 feet away.

I put the other 3 on long cables.
1 in the rear light (plastic and above the frame) or high up in the seat back fabric pocket where it sees the best signal.
And the remaining 2 go either side of the seat under the seat tray near the edge.

In this way I can rotate the chair 360 degrees and always see a receiver one way or another.

The chairs metal works as a very affective faraday cage at 2.4ghz. So using 1x rx unless you are very close to it you will see signal dropouts and failsafe often at various positions. Even putting a rx close to a metal chair reduces performance markedly.

Also it pays to know which is the ACTIVE antenna, and which is the ground(plane). See picture of quad with arrow. The antenna pointing down is the active one. This gives at least DOUBLE the range than fitting this RX the other way up. There are 3x remote RX's on this quad. I get reliable safe operation with zero complete signal losses at 3 to 4 miles away with this same setup on my power glider. (http://www.wheelchairdriver.com/12x.htm boosted transmitter)

[rustyjames]

I think rustyJames and I are in the same boat. I just purchased a used Omni from ebay, and is due to arrive tomorrow. I got it for $105 US$. I still have yet to find a spectrum for decent price, maybe they are not so common here, as their are alot of other brands for sale. The other cable software I was referring to is the Neutrik RS232 cable SA76525 and the PC programming software for it. It works great, I'll tell ya, you would really hate to be sitting in that thing at full turn speed and acceleration set to max. CRAZY fast.

Woody, and me to the list too!! Cant wait to see it in action.

Funny, I was bidding against you on that Omni, sorry I made you pay more! I was going to go a lot higher because it came with the cable, which alone goes for around $50.00 on ebay. I stopped because I had bought a new one a few weeks ago, but I paid about $170.00 for it with the shipping. I hope it works.

[woodygb]

Woody, can you configure the system so that you just plug in say 1 to 4 satellites only? As the helicopter flybarless systems do. No rx needed as such.

..I now understand what your asking ...the answer is NO.

The Omni / Arduino interface will/should be the equivalent of your 2 speed controllers.
I can just configure the voltage output in software rather than adding resistors... I can also add in led indicators ..I currently have a pair of 5mm Tri colour led's ... one for each channel...on my desktop test rig to indicate Neutral ( RED ) ..Forward and Left ( BLUE ) Reverse and Right ( GREEN ) .... plus one 3mm to indicate when the configuration button has been pressed.

The BLUE and GREEN come on when the preset deadband is exceeded...this is currently 1560 and 1440 with the R/C signal spread being from 1100 <-1500 ->1900...

They led's could easily be left out ...but I find it convenient to have a visual cue as to what should be being output.

The pod interface setup that I'm trying to perfect is much the same.... the Arduino becomes an Omni type interface ..in that it accepts signals from the R/C and the Pods joystick ..in that case I have the pods joystick deadband set slightly lower than the R/C signal deadband thus input from the pods joystick will ..via software ..always have preference over the R/C transmitter.

[Burgerman]

preset deadband

My existing setup has no deadband, just a linear voltage change (pulsewidth) from 0v to 5v. Lowered by 3 (adjustable) resistors. One each end, one for centre voltage. (works like the transmitter trim - which is subsequently disabled on the transmitter)

No deadband works great as the pilot plus already has one that's bigger than I want!

Does it need this? I do have a small expo set up so that the ends of the stick do about 10 percent more. But this isn't really needed. Just feels nicer.

Is there any benefit to using 2048 resolution transmitter and receiver? I doubt it on a powerchair. It matters on fast planes etc.

[woodygb]

No deadband works great as the pilot plus already has one that's bigger than I want!

...Ah! ..new info.

OK.

For the Omni interface I could remove the deadband from the voltage output so it matches your linear setup and just use deadband cues as a software switch for lighting the led's if they're present.

As for the resolution ..I'm sure that I could do that if required...but you'd need to tell me IF it's beneficial for Wheelchair control.

[Burgerman]

Well using full throw, and normal endpoints theres no detectable difference. Most cheaper RC setups only do 1024 anyway.

But the better ones do 2048 resolution since flying a fast plane with the "rates on" so that you are only using about 20 percent of total servo travel at full stick, means it matters. Also matters with mixing etc where only small movements are involved.

I think for powerchair use and remembering how "soft" and delayed control is anyway that it will have no affect. Where it DID have an affect was when I used just a small throw (10?? percent servo travel) to drive the speed controllers. To get the 1.2v swing - it was not very smooth!

[RC Hopeful]

I think rustyJames and I are in the same boat. I just purchased a used Omni from ebay, and is due to arrive tomorrow. I got it for $105 US$. I still have yet to find a spectrum for decent price, maybe they are not so common here, as their are alot of other brands for sale. The other cable software I was referring to is the Neutrik RS232 cable SA76525 and the PC programming software for it. It works great, I'll tell ya, you would really hate to be sitting in that thing at full turn speed and acceleration set to max. CRAZY fast.

Woody, and me to the list too!! Cant wait to see it in action.

Funny, I was bidding against you on that Omni, sorry I made you pay more! I was going to go a lot higher because it came with the cable, which alone goes for around $50.00 on ebay. I stopped because I had bought a new one a few weeks ago, but I paid about $170.00 for it with the shipping. I hope it works.

Amazingly small world when you get down to it I guess. Lets hope we don't do the same on a transmitter / receiver.

[RC Hopeful]

Thank you both for the links and info, interesting read. I can say I learned something today

[RC Hopeful]

OK Rusty James, I almost did it to you. I was going to up the bid on the Ebay DX6i that you have at $123.56, then I saw the name and figured it was you. I guess I will pass on bidding this time around. I am still on the look out for a controller.

[rustyjames]

OK Rusty James, I almost did it to you. I was going to up the bid on the Ebay DX6i that you have at $123.56, then I saw the name and figured it was you. I guess I will pass on bidding this time around. I am still on the look out for a controller.

RC, I'm not bidding on anything on eBay at the moment, so if you see something you like go for it!