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KSN770 - opinions?

Oh and it’s “Full VGA” – no less!!!

My KMD550 is 1/4 VGA (320×240) and it works fine

But if you want to improve the functionality (put in more features) you need more pixels.

FWIW, I don’t think more than 640×480 has any point at the typical panel distance. This image is exactly 640px

Also I think there are real issues with finding an LCD which is modern hi-res and can have the availability assured for say 10-15 years. One could solve that by buying a lot of them but you could have $millions tied up in stock.

Administrator
Shoreham EGKA, United Kingdom

FWIW, I don’t think more than 640×480 has any point at the typical panel distance. This image is exactly 640px

My mobile phone has 2560×1440 and I love every pixel of it. My desktop monitor has 5120×2880 and I would never want to switch back. So no, I completely disagree…

My mobile phone has 2560×1440 and I love every pixel of it. My desktop monitor has 5120×2880 and I would never want to switch back. So no, I completely disagree…

Yes, but the mass market uses these devices to watch a rather “different kind of data”, usually

(photos and movies)

Avionics is mostly predefined symbols, fixed size pixel groups.

What I am getting at is that I would not up the screen res from 640 to say 1280 if it makes it 4x slower to zoom and pan (which it will do). Even the GTN750 is pretty irritating on the redraw speed.

Administrator
Shoreham EGKA, United Kingdom

Graphics hardware that can zoom and pan instantly on 2560×1440 is very cheap. No excuse if a device is slow, it’s 90% due to poor engineering.

On an EFIS, the graphics get tilted which produces very visible artefacts, down to Moiré patterns. More resolution could do wonders. Same for navigators, a lot more detail could be provided on the map. Fonts would be a lot crisper and easier to read.

“Also I think there are real issues with finding an LCD which is modern hi-res and can have the availability assured for say 10-15 years”

If I may be excused for stating the obvious – how many makers of VGA screens still around that offer assured availability fifteen years from now for a low-volume product?! I am amazed that someone is still making them now, let alone fifteen years from now.

Aside from that, I was pointing out at the brochure for singling out “Full VGA” as if it were somehow a top-notch feature for a modern consumer electronics product.

it’s 90% due to poor engineering.

Of course…

how many makers of VGA screens still around that offer assured availability fifteen years from now for a low-volume product?!

Nobody will assure supply for that long, but you need to use one cheap enough that you can stockpile enough of them to give you time to re-engineer it when it becomes necessary.

You get the same issues with the processor stuff.

I am amazed that someone is still making them now

There are lots of people making industrial LCDs.

Aside from that, I was pointing out at the brochure for singling out “Full VGA” as if it were somehow a top-notch feature for a modern consumer electronics product.

Yes – that is just stupid.

Administrator
Shoreham EGKA, United Kingdom

What’s the price differential between a proper modern LCD and a “modern” VGA LCD? Can’t be that huge in order to prevent stockpiling… and shouldn’t be a problem to pass it onwards. Especially when you have the b@lls to put a 15k price tag on a product which is already 20 years old when you get it out of the box.

It is many years since I designed a product with an LCD but one challenge might be the temperature range of certified avionics – especially the -40C bit.

One can put a controlled heater on the back of it (and I believe some avionics LCDs have that) but it won’t help with the startup. A display which is invisible for say 1 minute is not acceptable.

It may be that LCDs with a decent temp range don’t come in consumer-grade resolutions.

Especially when you have the b@lls to put a 15k price tag on a product which is already 20 years old when you get it out of the box.

I would give these firms a bit more credit. They have to achieve various objectives e.g.

  • the temp range has to be “industrial” i.e. -40 to +85 on everything
  • probably using 80×86, to enable rapid development on a PC and to get a fast cheap processor
  • very hard to get good engineers to stay in the job for long (slow pace of product development is bad for the CV) so software will have loads of bugs, so you need lots of QA to sort out all the crappy C++
  • analog expertise gets scarcer every year
  • have to test with every piece of avionics shown connected in the FAA approved IM (yeah I know some don’t actually do that)
  • most interfaces have to be reverse engineered… you may have the data protocol but not the data timing
  • many installers have very little expertise beyond simple wiring
  • repairable for say 10 years, with the ~$1000 flat rate repair covering e.g. a whole new PCB because the 80×86 processor is not made anymore
  • create some kind of upgrade path where for a few k you can change the main board for new functionality

Whereas e.g. an Ipad needs to work for a few years and then it goes in the dustbin.

At work we stockpile some parts. And one can dispose of them to the surplus stock cowboys afterwards, usually. Currently I am sitting on a 5 digit value of a Hitachi H8 processor stock!

It will be more than funny if Honeywell/BK did all this and the KSN770 flops totally in the marketplace, like the KFD840 did before it…

Administrator
Shoreham EGKA, United Kingdom

A display which is invisible for say 1 minute is not acceptable.

The GNS430/530 barely react at 0°C and I do not want to know what they are like when at -40°C. So it is acceptable in fact…

•the temp range has to be “industrial” i.e. -40 to +85 on everything

Why? I’m pretty sure humans aren’t designed to operate a cockpit in a -40 to +85 range….

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