OSD on the ground?

[jimmaplesong]

Hey Sander,

I've been thinking about how the EzUHF is full duplex... and has the capability to transmit data back down to the ground. It's also connected via i2c to the EzOSD's GPS onboard... which could be handy.

What I'd like to buy someday is a system where the On Screen Display happens on the ground. The GPS part of EzOSD would still be in the air, and EzUHF would transmit all telemetry to the ground more reliably than depending on a audio / video link. All you need then is an artificial horizon, and customers could fly IFR even when the video link fails for longish periods of time.

Later,
-Jim

[Crash]

Or even better, an all in one UHF RC receiver/video transmitter. If it has the capability to send telemetry through the RC link, why not video too? Bandwidth?

[sircana]

Hey Sander,

I've been thinking about how the EzUHF is full duplex... and has the capability to transmit data back down to the ground. It's also connected via i2c to the EzOSD's GPS onboard... which could be handy.

What I'd like to buy someday is a system where the On Screen Display happens on the ground. The GPS part of EzOSD would still be in the air, and EzUHF would transmit all telemetry to the ground more reliably than depending on a audio / video link. All you need then is an artificial horizon, and customers could fly IFR even when the video link fails for longish periods of time.

Later,
-Jim

+1. I would definitely buy one of these. Telemetry should be sent through the strongest link, which is UHF. On the other hand, we will finally free the audio channel on mono video tx (like Lawmate), and get audio from onboard microphone.

[ssassen]

Hey Sander,

I've been thinking about how the EzUHF is full duplex... and has the capability to transmit data back down to the ground. It's also connected via i2c to the EzOSD's GPS onboard... which could be handy.

What I'd like to buy someday is a system where the On Screen Display happens on the ground. The GPS part of EzOSD would still be in the air, and EzUHF would transmit all telemetry to the ground more reliably than depending on a audio / video link. All you need then is an artificial horizon, and customers could fly IFR even when the video link fails for longish periods of time.

Later,
-Jim

Ha! Sounds like a good idea, put it won't work as well in practice.

Currently the telemetry is sent down via the audio channel, it is trivial to do a ground based OSD with that. Actually we already have that, just connect the audio output of your groundstation to your notebook and run our ImmersionRC player, it'll do real time decoding of the telemetry. Using the UHF for sending such data down isn't practical as the maximum supported data rate is pretty low, also, you'll be eating into the latency for the RC control, as you can't send and receive at the same time. For that purpose the audio channel is much better suited, it has higher bandwidth and hence can be used to transmit much more data.

Cheers,

Sander - ImmersionRC

[ssassen]

Or even better, an all in one UHF RC receiver/video transmitter. If it has the capability to send telemetry through the RC link, why not video too? Bandwidth?

Nah, what if that link fails, you lose it all. It is better to have control and RC separated with the control having much further range than the video. The only way this would work is if the entire link was digital, hence digital video and RC, that way around you can do lots of trickery with data packets which you can't do with an analog signal, we're not there yet, maybe in 5 years, but too complex and costly at this point.

Cheers,

Sander - ImmersionRC

[ssassen]

... and get audio from onboard microphone.

For what purpose? Listening to the wind noise?

Cheers,

Sander - ImmersionRC

[Keith]

You gotta fly low and slow to hear people yelling and lawn mower engines on the ground! lol

Honestly though, I do use the audio as an indication of motor RPMs. I've flown without it and felt like something was missing, and wasn't comfortable. That said though, I always either tuck the mic down into the fuse away from wind noise, or in the case of the GoPro, I tape over it and block the wind noise distortion so I can hear the motor running.

[SENTRY]

Not to mention - digital is either on or off - period. I laugh at people when they say "I have 4 bars so I have great signal here for my phone." - LOL. Yes you may have a good signal - but what you DON'T know is what the noise floor is. So digital is GREAT when you do have a signal - but w/out warning it could be 0. Like Sander's says - bye bye plane.

I don't run mics. The plane hearing ME (a PA system) would be more useful that me hearing the plane... this way I could talk to people as I fly over them. Or if I crash w/ video I can tell the people who are investigating that I'm the police and to leave it alone.

[sircana]

For what purpose? Listening to the wind noise?

Cheers,

Sander - ImmersionRC

I know, I know, old discussion...

Real pilots fly with headphones, an so on.

But, I miss the feeling of the speed, motor rpms, servos, etc. I had before using the audio channel for telemetry.

[jimmaplesong]

Using the UHF for sending such data down isn't practical as the maximum supported data rate is pretty low, also, you'll be eating into the latency for the RC control, as you can't send and receive at the same time. For that purpose the audio channel is much better suited, it has higher bandwidth and hence can be used to transmit much more data.

That makes sense. I experiment with some 2.4GHz wireless mesh microcontrollers from time to time, and I have noticed that it tops out at 40kbps throughput (theoretical 56kbps,) and glitches with a noticeable delay when the mesh does its 'ping to discover everyone nearby' routine.

Packet-based communications that would, like WiFi, seem to be bi-directional will never match a dedicated channel when it comes to latency. Maybe we just need two different UHF-range frequencies that are each as reliable as the single UHF link now.... eventually.

<crazy thinking> Either that or we'll figure out how to utilize in to those amateur satellites that HAMs share now, or maybe something by then we'll just be using some directly-on-the-internet control made possible by something like 802.22 (http://www.tekgoblin.com/2011/08/01/...-square-miles/ ) which should cover a huge area at up to 22Mbps With that sort of connectivity in the air, we'll stream HD direct to the web some day! </crazy thinking>

Edit: the 802.22 range and bandwidth would require some extra power of course... total bubble-bursting analysis on slashdot. http://mobile.slashdot.org/story/11/...0-Square-Miles