Re: Gadget Poll

Good, but I don't think a flashing LED, particularly in a high light environment would be as good as an audible alarm.

Red S.

I agree with your thoughts Red, but in suggesting the LED I was thinking of something an owner could add to their xmitter themselves - while the audio alarm would be good/better/as well as, some guys/girls might find it a bit daunting to build and install, compared to simply drilling a hole and wiring a flashing LED with series resistor.

The advantage of the flashing LED is that it can be on all the time, whereas an audio signal needs detection circuitry to check the condition of the sticks etc.

David

Red Scholefield wrote:

Airtronics RD series radios beep when power has been on for 15 minuets.

| > This post is an inquiry to see what kinds of gadgets the rc modeling | > community might find interesting or beneficial. | ... | > Suggestions? ... | IMHO, the RC control system has evolved the wrong way; all the clever bits | are in the transmitter, they belong in the aircraft.

Except that adding smarts to your plane will add weight to your okabe

-- exactly what you don't want in your plane.

Granted, this was probably a much bigger issue 20 or more years ago, when receivers were big and didn't do much -- now, they can pack all sorts of functionality into a tiny little package.

| The gadget would look like this. On one side of the gadget there is | a set of sockets that plug directly into the servo pins of the | receiver. The opposite side of the gadget has a set of pins into | which the servos are connected. In effect it intercepts the | channels, adds value to the control system.

And adds weight, and another point of failure.

Really, things like this ought to be integrated into the receiver, rather than having 8 extensions between it and the receiver. So if you do do it, I'd suggest building in a receiver as well.

| OK, the user can now do mixing in the aircraft, so what? Here's the business | case: | | With current technology, the RC buying public are accustomed to paying top | dollar for fancy transmitters. Its accepted that if you want to do fancy | mixing, have lots of model memories, or just impress ones buddies, you get | a top end radio. The flight computer can change all that.

How can it impress my buddies if the can't see it, because it's buried in my plane?

| You can buy a cheap gadget (compared to the premium of a top radio) | and use it with a low to mid range radio.

`Cheap' being $50-$100.

| Don't worry about how many memories it has, get one for each plane.

So if you have 5 planes, you're saving $150 on your radio (computer radios are relatively cheap now) but spending 5 * $75 or $375 more for your planes. Makes perfect sense.

| Want a fail safe setting, no need to go PCM, the flight computer on | a PPM Rx can be programmed to take care of signal loss situations.

Many of the new PPM RXs have failsafe settings now, and they don't even cost much more.

| Its time to adjust the mixer settings: no cryptic 2 line LCD display | to navigate, the flight computer is USBed to a commodity PC for a | full screen GUI novice friendly mixer program.

So, you can't adjust mixes in the field without a laptop? That's not going to go over well. (Having to shut the plane down, bring it over and open it up to find the USB port is another problem that people won't like.)

| Need to drive 14 servos and the up-link is limited to six channels: | the flight computer can compute additional controls from the | available primary channels.

Now, that might be useful.

| How about data logging, no problem, the USB port on the gadget can | double as a data dump for optional on board inputs. Even without | additional sensors, it could count glitches, monitor battery | voltage, monitor servo current draw.

Ok, this thing isn't going to cost $50-$100 any more. The Eagle Flight Data Recorder does most of these things (but not all) and a few more and it costs $170.

Really, if you want to monitor all this stuff, your monitor ought to have the receiver built in, just to avoid the need for all those extensions. (Actually, if you just want to monitor servo positions, your transmitter ought to be able to do that by itself.)

| More than one mix for different flight modes. Use the non proportional | channels as a binary mode selector (00 = landing and take off, 01 = tame | settings, 11 = high rates, 10 = inverted). Program the flight computer | with different control responses in each mode.

Of course, computer radios have this now ...

| Put the flight computer into the control loop. Hook up a gyro and get the | computer to maintain height, direction, speed, etc in a nominated mode. | Hook up GPS, and get the computer to fly way points.

| There's a potential market out there for folks who are adverse to | expensive transmitters and/or would like to dabble with computer | control of their models.

If you add all this functionality, it's going to be so expensive that only a very few people will even want it.

| Except that adding smarts to your plane will add weight to your okabe | -- exactly what you don't want in your plane.

okabe = fingers were off a bit. I meant to type `plane' :)

| So if you have 5 planes, you're saving $150 on your radio (computer | radios are relatively cheap now) but spending 5 * $75 or $375 more for | your planes. Makes perfect sense.

Case in point:

You can buy mixers that mix two channels -- they work quite well for things like elevons, flaperons, V-tails, differential thrust, etc. It's a simple device, but it can handle a lot of the mixes one would need a computer radio for.

But from what I can see, they're very rare. Almost nobody wants to spend $20/plane for these, when they can save the weight and spend a little extra on a transmitter that can do it for them, for all their planes.

I just don't think any sort of uber-smart mixer that you put in your plane would sell very well.

Not bad. A microcontroller chip that could do the entire job can be had for less than $5, and will weigh, well, less than the wire to connect it. Piggyback a tiny card on the receiver. You could even remotely add to its program in the field, given a smarter transmitter, allowing for lots of possibilites.

Having a backchannel for status information would also be very cool, allowing one to build sensors into the aircraft for things like rate of climb, airspeed, altitude, and even possibly attitude (or maybe rate of bank, which would be easier and lighter.) I have a 933MHz transmitter card that is less than an ounce, which would probably do the job. It can transmit at 4kbps...

The real thing would be a wifi channel between the plane and your transmitter. Real time video, backchannel status, fast uplink for control and programming information. I have a $15 wifi card for my PC that is extremely light (almost nothing to it) and I'm guessing that most of that weight is the PCI interface. I know a guy who uses wifi over 2 mile links, using a parabolic dish. He uses those tiny pcmcia radios with a laptop. Seems like a wifi system could be made to do 800m...

Or how about a cell phone interface? Most carriers have a data option. It wouldn't be enough for real time video, but it would definitely be enough for sensors and the occasional picture.

Bob Monsen wrote in news: snipped-for-privacy@comcast.com:

Okay, just for my curiousity - do the people he's sharing the wifi connection with *know* that they're sharing a wifi connection with him?

It's a point-to-point connection for a remote village in the Dominican Republic:

Hugh: Do you think you could email me a copy of the schematic and article for that engine synchronizer? This is exactly the problem that bothers me about twin engine projects. Now if we could develop one that automatically kicks in the appropriate rudder to compensate for the engine out condition, we'd have ourselves the idea goodie- Thanks- Paul please remove the "dontSPAMme." from my address to reply

Hugh Prescott wrote:

Paul, The first part of that should be easy. Measure the output of a digital tach and when it goes to zero swing the rudder to the correct side. The real question is how much rudder?

This is where having feedback to the ground would be really helpful, as you could get an alarm signal from the transmitter. I'd go for a scheme that measures differential rpm's and applies the appropriate rudder. This would allow for an engine that sags or doesn't wind up when you hit the throttle.

Another alternative, or use in conjunction with rudder coupling, would be to retard the fast engine to match the slow engine. The pilot could cycle the throttle stick to return power, knowing what he's getting into, much like arming an ESC.

As for how to calibrate all this, I'd use a separate channel for the second engine and slave it to the throttle. Pushing the throttle advances both, while turning down the other proportional channel would retard the second engine. You can then figure out how much rudder you need from 12 mistakes high, give or take a mistake.

On Wed, 27 Jul 2005 21:13:42 GMT, Paul Ryan wrote in :

I'd like the e-mail information, too.

Thanks.

Marty