PINNED - Plug & Play PGDT for Radio Control

[Burgerman]

DX6 and DX6i are different. DX6i is "full range" and not just for park flyers.

Also The latest DX6i is DSMX capable, earlier ones are DSM2 only.

The diffence is that DSM2 uses fixed frequency on 2 channels, and DSMX channel hops and is better in noisy areas where there are other 2.4ghz equipment such as Bluetooth on phones, alarms, wifi routers, microwaves, IP cameras, etc.

So try and get a DSMX one if possible.

And... http://www.rcuniverse.com/forum/rc-radi ... sions.html

To find out: http://www.youtube.com/watch?v=4_Tbes9f1_c

[rustyjames]

Thanks for clarifying!

[SMA Dad]

Could you throw me some data on the Omni as it seems that interfacing with it should be a piece of cake.

Hello Alan,

Very interesting work you have going here. I've uploaded the Omni+ manual that contains electrical specs. I'm looking forward to anything you can share on the Arduino / Omni+ interface circuit. I have two Omni+ units and would be happy to test ideas. I have been working on an Omni+ /Arduino / Wii Nunchuk interface to replace the standard Pilot+ attendant control which I despise. I have the Nunchuk /Arduino side working and looking for a solution to the Omni interface.

Best of Luck

PS: The file was renamed to omni.txt. It is actually a PDF so rename to omni.pdf to open. For some reason I couldn't upload a PDF?

[SMA Dad]

Sorry, I can't seem to upload a file regardless of extension but the following is a link to the document right here on Wheelchairdriver.com...talking about a recursive round-a-bout...jeeez

http://www.wheelchairdriver.com/pdf-files/omni.pdf

[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.

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

Thanks BM for the RC TX difference.

RustyJames As far as E-Bay to late now, no big deal, I saw the name on ebay as R*******S and figured it was RustyJames

[ex-Gooserider]

FWIW, my recollection from the announcement that eBay made when they switched from showing bidder names to the current format is that the "names" shown are random, and don't match up in anyway to the actual usernames of the bidders.

I think that for a given auction, if a given bidder makes multiple bids (including automatic bid increments) their name will stay the same, but that the same person may get different names in different auctions...

Bottom line, there isn't a way to easily tell if you are bidding against someone you know...

ex-Gooserider

[rustyjames]

RC, I'm not buying anything until I know what I'm going to need, and at this point I'm lost!

[woodygb]

I have the Nunchuk /Arduino side working and looking for a solution to the Omni interface.

My TEST output to the Omni will be via a 2 Channel Non Volatile Digital Potentiometer using SPI control which my VSI test rig seems happy with.... I did try injecting the PWM from pins 5&6 on the Arduino into my VSI ...but it didn't like it.

The Digipot has 257 steps so voltage will be approx. 0.01v per step.

Here's a snippet of code for the Digi Pot. ..... Email me for more info.

void digitalPotWrite (int address, int value){
// take the SS pin low to select the chip:
digitalWrite (slaveSelectPin,LOW);
// send in the address and value via SPI:
SPI.transfer (address);
SPI.transfer (value);
// take the SS pin high to de-select the chip:
digitalWrite (slaveSelectPin,HIGH);

[woodygb]

Here is my first trial Omni interface.

omni interface 2.jpg (232.36 KiB) Viewed 17575 times

DB9 Plug to the Omni ...also supplying 12v power to the Arduino... The Arduino has a small voltage reg and this is dropped to 5v... enough mA should be available for the Arduino and the led's BUT NOT THE RADIO RECIEVER...which will require it's own supply.

R/C Reciever leads.

Blue = GND / Common/ Reciever Negative
Yellow = Ele / Throttle signal
Orange = Aile / Steering signal
Green = Rud / Omni ON/OFF signal

2 Led's that give an indication of Throttle and Steering ... they simply get brighter as the Fwd/Reverse or Left/Right signal increases ...Neutral being Led's OFF.

The Blue wire to the Jack plug will supply an ON/OFF signal to the Omni by taking the relevant pin to GND... it is held @ 5v until the Rudder signal exceeds 1700.

The twisted Red and Black wires ( 5v supply ) are only present for bench testing ...

Next to the 2 Red Led's is a push button to initiate calibration of the R/C Transmitter signal .

With the Transmitter and Receiver turned on and the Transmitter sticks in NEUTRAL ...Press the button ... a Red led on the reverse side of the box comes on indicating that calibration mode has been entered .. then simply move the sticks Ele,Aile & Rud to their extremes in the vertical and horizontal planes .... you have 15 seconds to do this.

Questions?

[Burgerman]

Are you sure it wont run a rx too? Mine runs from the Omni output, via the 5v out, from a voltage reg chip. Not efficient but it works. Maybe double the efficiency with a tiny DC to DC inverter from ebay, they are cheap?

Having a separate supply kind of makes it difficult in comparison.

Question1...
What happens with no RX supply?
Question2...
What happens if we turn off or external supply removed in operation etc?

And q3...

Your RX has a null (no) output on failsafe.
Most cheap spektrum default to neutral, or low throttle. Better spektrum allow programmable fail safe positions (so can choose say full rudder for turn off?)
Most other manufacturers also have programmable fail safe.

What happens in each case? Neutral signal, no output etc?

And can I have one! Your PayPal address? I could do with another. Cant face building another one it hurt my brain cell the first time around!

PS... It wont let my chairs run off and wreck my house/van/college/etc will it? Code is safe? Obviously no guarantees... But what do you think?
I will fit a vid link camera, use my video goggles, and my long range boosted RC transmitter and do a very long range 4 mile away along the beach test! That's a lot further than you are visualising

[woodygb]

I assumed that the Omni's 12v 100 mA wouldn't be sufficient to supply the Arduino and the R/C Receiver.

The Arduino's onboard regulator is only small and it MAY be man enough to supply the Arduino and a R/C Receiver.

The voltage regulator on the mini has a maximum output current of 100 mA. The Atmega usually drains 30-50 mA so you have 50-70 mA to power

..external devices.

So ...I was simply erring on the side of caution.

Question1...
What happens with no RX supply?

Should the signal to the Arduino fail completely then an "out of range signal" should be present and the output becomes 2.5v = Neutral.

I think that the above also answers Question 2.

My Receiver outputs a programmable failsafe signal ... it's set as Neutral = 2.5v
The programming also contains the NULL failsafe possibility and again the Arduino's output becomes 2.5v or Neutral.

I'll let you have this one for testing next week .

[woodygb]

I did buy two of these ...

http://www.ebay.co.uk/itm/281218773432? ... 1439.l2649

but thought that it might be easier to use the Arduino's on board regulator ... very little problem to use a bigger project box and incorporate it into the Omni interface.

In fact I already have a setup that uses one.

002c.jpg (250.6 KiB) Viewed 17397 times

[LROBBINS]

Woody,

Do be cautious about how much current you draw from the Arduino's regulator, especially if you are feeding it at 12V. It has no heat sink and with 12V input there will be a lot of calories to get rid of.

Ciao,
Lenny

[woodygb]

I agree ...hence my wish to only run the Arduino and a pair of Led's from the on board reg.

It's no problem to just use a separate 5v supply and not use the Arduino regulator at all...I just need B.M. to be precise about exactly where on the Omni he is wanting to get his supply voltage.

[Burgerman]

Anywhere you wish! From your D connector. 12v, plus a 1 amp reg chop? Common ground and 5v for rx?

[woodygb]

The Omni D connector say's 12V 100 mA ...is this sufficient?

EDIT:- Note that I have little clue what your receiver and 3 or 4 Satellite receivers might draw in the way of mA's

D omni.png (19.49 KiB) Viewed 17374 times

On my larger test box I'm getting the supply for the regulator via the Charging socket.

[Burgerman]

each satellite is 15 to 20ma and I have 3.

The main rx - don't know, but likely about 30ma to 50ma...

Works from 4v to 9v. So an inverter would reduce current draw (12v to 5v so about half?)

[woodygb]

OK... If your sure ...as it's plugging into your Omni.

I'll just add on an external 5v regulator powered from the Omni's 12v.

[LROBBINS]

3 x 20 + 50 = 110 mA and if you are just using a linear regulator to go from 12V to 5V you will be drawing all of that (actually a bit more) at 12V and exceed the Omni's spec. There are single chip DC-DC converters that need few or no external components, essentially pin-for-pin substitutes for a 740x, that would reduce that drain to say 10-20% more than 5/12 of the 110, hence safely within the Omni's ability to source it. There are also single chip converters that would go directly from 24V to 5V (Recom, for example, makes more than one, and there are others). Those Chinese converters will not be very efficient at such a low current draw - the parasitic loss is almost constant so becomes a big percentage as current use goes down. I also wouldn't trust their electrolytics to be very durable at 24V.
Ciao,
Lenny

[woodygb]

Care to recommend a specific chip?

I have a couple of LM7805CT's kicking around.

[LROBBINS]

I'll dig up some this afternoon. The LM7805CT is a linear regulator so the drop from 12 to 5 will just be lost as heat and the current drawn from the omni at 12 V would be the same (+ a bit) as that drawn at the 5V side. Right now I have to take the dog out. Ciao, Lenny

[LROBBINS]

I am using several Recom 5V DC-DC converters Recom R-78AAxx-0.5_SMD.pdf. They are not 3 pin substitutes for the 7805, but need few external components, in many uses none, and they have a control pin so that the Arduino Nanos can turn it on and off in response to CANbus messages - power on all modules is controlled without any extra wires.
http://uk.rs-online.com/web/p/switching-regulators/7063932/?searchTerm=R-78AA5.0-0.5SMD&relevancy-data=636F3D3226696E3D4931384E4B6E6F776E41734D504E266C753D656E266D6D3D6D61746368616C6C7061727469616C26706D3D5E5B5C772D5C2E2F252C5D2B2426706F3D313326736E3D592673743D4D414E5F504152545F4E554D424552267573743D522D37384141352E302D302E35534D442677633D424F544826
It is SMD but the footprint is the same as a DIP so you can also solder it to DIP pads or bend the leads to fit an IC socket. Input, for 5V out, is anything from 6.5-32 V and it has a 0.5 A output with high efficiency even at low current.

Tracor has a cheaper, 1A, 3-pin through-hole mount converter, but without the sense pin. The external components needed are like those needed for a 7805.
http://uk.rs-online.com/web/c/power-supplies-transformers/dc-dc-converters/switching-regulators/?applied-dimensions=4294964745,4294844985&esid=cl_4294967294,cl_4294958417,cl_4294957161,cl_4294957193,cl_4294956957,cl_4294957383&m=1

There are others with exactly the same form factor as the 780x series so they can be directly swapped on an existing board, but you'll have to search a bit to find them - I don't have any links handy. Pololy has one, but it actually costs more from them than the Traco (which can also be ordered from China much cheaper, but with a loooong delivery time.) Recom is German, though I don't know where they're actually assembled, but I never found a really cheap source.

Ciao,
Lenny

[mous3]

I'm interested in this for later on I have 37mh with full fail safes and stonking range of 3miles with telemetry feed back and video (from a drone that I made and flew, Im not using the gear now). Will I be able to use this on my VR2 as I walk off from my chair and often get stuck unable to walk back to it.
as it wil be 3 years before I have a new fully trained service dog who can go and get it for me or help me back to it. yes dogs can drive power chairs just not on or near roads.

[LROBBINS]

Correction. I just looked through the Tracor data sheet. Like the Recom, it does not need any external components unless input voltage goes over 32V (in which case an input capacitor is needed) or you need to meet class A noise requirements (in which case two input capacitors and a choke are needed). In other words, an easy to use efficient device that doesn't cost an arm and a leg.
Ciao,
Lenny

[woodygb]

Cheers for that Lenny,

The Traco seems ideal.

I'd have answered earlier but was replacing the rear brake slave cylinders on my OLD Vauxhall Astra ...I was going to replace the shoes as well... but unfortunately those supplied by the motor factor were not wide enough by 16mm ....

[woodygb]

Arduino based interface finally posted off to you B.M.

It's a revised layout in a different case...see blurry pic

001A.jpg (42.83 KiB) Viewed 17853 times

[woodygb]

The USB interface isn't required ...but I've included it just in case you want to download the Arduino software and watch the data via the Serial Monitor.

I've also included a DB9 Male plug which can be used instead of the OMNI's Port to allow remote bench testing ..it simply has a power IN and two joystick voltage OUT connections to stick your meters probes into .

The four wires on the bottom line of the DB9 plug are RUD ,AILE , ELE & GND ... the Receiver will also require the RED 5v from the 5 pin row.

See drawing

OMNI CONNECTIONS.png

[woodygb]

The DB9's in the picture are wrongly titled they should both be titled MALE.

Additional info on the interface.

Initially the interface could have R/C pulse value that doesn't match exactly with that of the owners R/C transmitter...

Calibration must be carried out and should only be required once. ... but can be done as many times as you want.

CALIBRATION .

Interface ON and R/C Transmitter ON.

Transmitter sticks in NEUTRAL.

Press the calibration button... (The LED's then pulse ON/OFF fairly slowly about once every second until the calibration period of 15 secs is over)...

During this 15 secs move the Transmitter sticks to their extremes in the vertical and horizontal planes and then let them return to Neutral.... LED's will eventually stop blinking and once they go OFF calibration is finished.

Note that there is also an 8 sec pause after the 15 sec calibration period when the LED's stay static ...this is part of the Arduino's program to allow ... iF your monitoring the Serial stream ... a 8 sec static screen shot of the calibration figures before they scroll off the monitor.

FAILSAFE .

A visual indication on the interface box of both LED's flashing fairly fast @ about 3 times per second.
Indicating that you have NO signal on at least one channel.... and the Arduino interface outputs 2.5v or neutral.

NORMAL operation.

LED's on the interface box will brighten and dim as the R/C signal changes ...
Led's OFF = 2.5v or Neutral ... above or below this voltage the LED's light and brighten as the joystick moves towards the two end points .

ON/OFF of the OMNI is via the Rudder Stick ... just a quick flick towards the left hand end of it's travel ... and the OMNI Jack plug.

[Burgerman]

Goody. Testing soon!

Do I get to keep one? This one? If so, how much do I owe you?

I will use a 10 channel RX with 3 extra satellites. And my 3.2w boosted transmitter. If I fit my tiny security cam and its transmitter, and use my FPV goggles, Should be able to send an empty chair around the park from my bedroom!

>>> I've also included a DB9 Male plug which can be used instead of the OMNI's Port to allow remote bench testing ..it simply has a power IN and two joystick voltage OUT connections to stick your meters probes into .

Not sure I get this bit!

[woodygb]

See how testing goes first... but I don't see why we can't come to a financial arrangement if your happy with what I've knocked up.

I would like the additional bits back .