PINNED - Plug & Play PGDT for Radio Control

[Burgerman]

Arrived! Delivered by an old Nissan micra by a mother and daughter!

[woodygb]

Excellent!

[Burgerman]

Unopened as yet. Will test soon. If it works I will throw away my 12 year old "analog" version!

[Burgerman]

OK calibrated my TX and RX to your device, which works easily. Once I figured out that 3.2 watts RF screws up the calibration...

So a note to calibrate further than 3 feet away may be helpful. But not many have high power transmitters.

Then test, worked but not quite correct. As it requires 3 clicks of trim to go right, and 22 to go left. And equal amounts but more, to go back and forwards.

So I calibrated the OMNI to the new joystick. Now all is equal and works, but there's a bit much dead band for my liking Not so much on left/right but on forwards/reverse. Its about double. You start to drive and you get nothing, then jerk and away you go. Same with turns but not enough to matter. The first 4mm of transmitter stick do nothing, then it seems to go but super slow speeds are not possible.

Having said all that its fine if you drive it around like I normally do... Its just that I hate the dead bit in the middle...

So I don't know if its the Omni doing this or your device. Its only slight. feels as if the first 10 percent of the stick not working. It didn't do it with my old nasty analog setup.

Either way it works!

[woodygb]

OK ... Bit more info from you would perhaps help me to improve it.

Do's the chair start to move as the LED's light? ...or is there a delay.

Can you see how many clicks of trim it takes before the chair moves?

[Burgerman]

My transmitter has adjustable trim sensitivity.
And is very accurate. Trims are about 60 steps left and 60 right for eg but I choose the level of "step" size..

It takes (once the device, and Omni is calibrated) about 10 "beeps" or 1/3rd trim left, same right.
It takes about 16 beeps forwards/backwards. Or almost half trim. It moves when the lights say it should. Hard to be sure. I already find the deadband on all powerchairs too big as it is so it may be just the Omni.

Its not like its bad, I am just used to RC helis etc. No deadband at all. Jumps at 1mm stick. Perfectly usable and I am happy to use it as is. Its just that I thought you may remove a little back/forwards deadband if you artificially added it.

[woodygb]

I have 40 steps each way on my trim ..which equals 100 of the signal range 1900 - 1500 - 1100 ..so from 1400 - 1600 ...and the LED's were lighting up after 4 -5 clicks.

The digipot has 128 steps in each direction and your presently losing ...due to the way I'm presently programming my deadband ..the first 6 steps = 0.06v.

I need some sort of deadband ..but it's an easy fix to make the deadband = 1 step ..

The LED's may however blink on/off @ neutral as the signal ...( at least on mine ) ..drifts a little.

[Burgerman]

Yes I think the deadband of the elev channel is double that of the aileron channel.
Its adding to the Omni deadband. Its not at all bad, perfectly usable, just noticeable.

The Aileron one is just noticeable. But the elev one is definitely about 60 to 80 percent bigger. Since I usually have it zero or nailed at 100 anyway it wont matter much!

Why would one be bigger than the other? Actually its a little bigger on my pilot plus joystick that I am using as I type this too. But its very close.

[woodygb]

Both channels should be the same.. I didn't detect any difference on my test bench or see anything different between the 2 in the programming .. ..I will however recheck.

[Burgerman]

Well it would be great if they both had the amount of deadband. But it may be in the Omni/pg controller.

My chair seems to do the same thing with the stock joystick too to a lesser degree. As in you need to move it further before the brake clicks forwards than side to side. Just ignore it, most people would never know the difference. I am just a bit sensitive to these things from flying fast planes, helis etc.

I cant fault it other than that. I just took the dog for a walk around the park, and drove the empty chair in front of me all the way around. Added a bit of exponential, and moved control all to left stick and I can drive my chair at the same time as the other one. Across roads, etc. All problem free.

[woodygb]

Here's the actual voltage readings that I'm getting with my multimeter.

Supply = 12.22v

Neutral = 6.07v ... the swing either side of this ( on both channels ) = 1.24 v so 7.31v and 4.83v

[woodygb]

I'm happy to supply the ( just finished modifying and the one I'm currently getting my readings from ) smaller version with an updated deadband if you wish.

[Burgerman]

So you could safely sell these to others as almost plug and ply, for Omni plus and r-net Omni.

You would need a list of suitable receivers though. And a comprehensive set up explanation. Regarding binding with preset fail safe, and keeping safe distance on calibrating your device, and then to calibrate the Omni. And safe testing info.

I tried fitting one RX that didn't have a failsafe (pre set fail safe) and it locks controls at the last known position. When I turn off my TX it just continues as it was at about 6mph. Almost straight into a wall. So I turned it back on fast. Same would happen with a signal loss. Or in a car or house with a lot of noise.

So you need either a rx that puts out no signal to the servos, or goes to PRE SET fail safe positions (stopped) on signal loss.

That rules out a lot of the smaller cheaper receivers. And allows
yours. But that means just one antenna and no auxiliary diversity antenna or rx. And I think they are needed on a metal powerchair.

[Burgerman]

How updated deadband?

[Burgerman]

Well you could. If its not too much trouble.

How much do I owe you?

[woodygb]

Same would happen with a signal loss

Your certainly right that any receiver that outputs a valid signal that ISN'T a preset neutral value or null is no good at all.
The Arduino will however failsafe on total signal loss ..try pulling out a channel wire from the receiver.

Deadband = Just less than 1 step thus you still get the first step ...so essentially ZERO.

[woodygb]

Arduino Pro Mini ATmega328P 5V £5

Project Box £10

MCP4261-502E/P Thru hole. £1

TRACO 5W Switching Regulator, 6.5 to 36V dc Input, 5V Output, 1A TSR 1-2450 £5

Bits & Bobs .... Led's , Resistors ..sticky tape Ummmm


Make it £25

[Burgerman]

Sounds good, to your paypal? Which email address? Thanks! The hard work comes free!

Sticky tape?

[woodygb]

Just being silly with the sticky tape.

PayPal

alanwood @ teamonslaught dot fsnet dot co dot uk

[Burgerman]

Done.

[woodygb]

I've finally managed to find a box that I like to house the ensemble ...a 9v battery holder seems to fit the bill nicely.

[woodygb]

Payment received...had me puzzled for a moment as to the senders I.D.

[Burgerman]

Among many other things I used to sell batteries online.

[woodygb]

I did remember.

We have previously ...in the long distant past... had a short discourse and during the intervening years ( before turning up here on the forum ) I had occasion to browse your various pages including the Optima page .

The 2nd link down on my ancient website directs people to your nitrous valve mod.
http://www.teamonslaught.fsnet.co.uk/tech.htm

[Burgerman]

Ah yes. Making stock 140psi air solenoid valves work with a 1000psi of Nitrous or CO2...

[rustyjames]

Woody, I'd like to purchase one from you, if you decide to sell them. Just PM me the price and payment details.

[woodygb]

What R/C kit do you have?

[rustyjames]

I didn't buy anything yet, I was holding off until you were ready to start mass producing them.

[woodygb]

LOL .. Mass producing!

I'm fairly confident that a Spektrum DX5 and AR500 that I've previously mentioned would be fine ..not that expensive and by a known maker.

However ... I'd really like to try out the interface on a DX5 / AR500 combo before being totally able to recommending it .
I'll see if I can persuade a member of the RobotWars community to allow me a quick test with one at the next event ... mid March.

[Burgerman]

Well having had a few lockups and runaways with powerchairs and helis (carbon fibre and big batteries etc I really do recommend something with at least 2 remote EXTRA receivers.

Because 2.4ghz can be blocked by the chairs metalwork, rear canes, or even reflections from walls indoors etc. Move 1 degree, or 1 inch to the left, all works again.

This is a bit worrying with a heavy powerful chair. Or a helicopter. The receivers antenna MUST have line of sight (no carbon or metal tube etc) for reliable 100 percent solid control.

As such my Roboteq chair has 4 receivers. Including 1 high up in the backrest. Easy to do with a permanent installation. And one each side, as well as the main rx.

Now I have a "flight log" device. Plugs into the RC RX. I can drive a chair about the house and then look at how many frame losses, holds, etc each remote rx shows. The result of this shows me that 1 single RX isn't very safe! Even in line of sight. Slowly rotating the chair shows different remote rx getting frame losses etc as the chairs metalwork blocks the signal.

So even on my remote Omni plus device, that has to be compact I have:

1 main 10 channel RX.
3X remote receivers.

That's 4 total, located in different places, and in different "planes". In this way I can drive behind cars, anywhere in and around my street, and there's always at least ONE receiver that is showing 100 percent solid connection.

Some pics...
This picture shows the Omni sat on a black box.
The black box contains Woodys interface board, and a 10 channel (AR10000 RX) on DSMX channel hopping 2.4ghz. Its antenna is horizontal.
On the rear corner, nearest you is an extra receiver, 6 inches away from the internal one, with its antenna in a different plane (vertical)