simple HUD

Nick uk.

I've been looking at some of the HUD's available and was wondering if it would be possible to get one made with these carrateristics;

L H

It would have three codes, the L' on the left would light red when po2 reached 1.1, a green fixed light from 1.1 to 1.35, and the H' on the right would light up at 1.35+

It's geared towards use on a kiss, or other manual ccr, in that it's early warnig system, 1.1 - 1,35 would i think help in keeping your pp02 as constant as possible, but isn't to say it's not suited to other units. It struck me that some other HUD's solutions with different flashing sequences seems a bit hectic, and might be difficult to remember a given sequence when thing start to go wrong.

What do you think about this sequence, a think it's simple and to the point, who might be able to make such a thing, (i,m a cheff and so the only eletrics i'm any good with are microwaves)

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paulraymaekers

hello, mine works nearly this way

solid green between 1.1 and 1.40

left orange middle green right red

there is more sequence: as long as you're in a safe zone (0.5 - 1.6) you get green with orange or red: this is instinctive: you see green only if you're in the optimal zone, you see green with orange (low) or red (high) if you're in a safe zone, but not optimal, and you see only orange or red if you're in an unsafe zone
the more deviation from optimal or safe zone, the more 'flickkering' (= distracting) of orange or red you get

for more than a year we tried diff colours, sequences, solid or flickkering..

at the end we got that solid=quiet=feeling ok
flickkering=distracting=not ok

regards
paul

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divetheworld

The flashing code is known as the Smithers code, it allows you complete redundancy to fly the unit on the HUD alone. Your after a go-nogo indicator.
There are a number of variants available, see posts by Darlene, Genesis and the Puffer website http://insane.bug-e.net/Puffer/PPO2/hud.htm for ideas.

Brent.

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Scuba_Vixen

This was a pretty good thread for implimenting a simple HUD to monitor 1 cell:

http://www.rebreatherworld.com/techn...ud+radio+shack



Darlene

dave t

My opinion, solid green is good your mind just blocks it out but the minute it starts to flash your brain recognizes it and alerts you to the problem. I have tried the "smitthers" style of flashing and I dont like it my (simple) brain just tunes it out and I dont notice when the pattern changes (are you listening Kev?))

happy new year to all

Dave

Genesis

The problem with solid is that if its microprocessor controlled there's no way to know if the controller is running or hung.

The first rule of displays is to make sure they don't display trash, especially in an application like this.

So if I was inclined to do something that was solid on I'd have it pulse "once in a while" (say, a short off for 1/4 second every 5 seconds) as a "health" indicator.

This way you have a crack at noticing if it stops running!

decoweenie

Dave,

IMHO, there is a basic principle difference between the "normal" HUD and the Smithers Code HUD.

The "normal" HUD (like the Vision, for example) is very close to the passive idiot-light concept in cars. When everything is fine, no flashes no alarms etc.

The Smithers Code HUD is a more active type system which communicates constantly to the diver. There is really no alarm, only information to relay to the diver the entire time. I think of the Smithers Code HUD is like a "numeric" gauge sending me a value instead of an alarm gauge.

So once you have change the mindset from what you expect from the HUD, I think you will like it better.

When I was diving the KISS-HH, the annoying thing was buddy kept coming to ask me if I am OK since they kept seeing the flashing LED infront of my face...

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Scuba_Vixen

I think you've hit on the key point here.

It's all about what you want your HUD to be for you.

Do you want it to be your primary sensory "full range" input device, or a more secondary device that's easier to monitor continuously while in the "all is going pretty well" range.

Depending on what the implementation details are, therein lies whether you could loose digital readout, but still maintain HUD function, or if it's HUD function that could fail, but still leave digital readouts functional.

Personally, I'd rather have the digital readout be the more protected, (electronically and physically) so that if I snag the wire to the HUD or something, I have the digital still working.

To borrow your car idiot light analogy, I see the HUD as more than just an alarm light, Mine is a "numeric gage", as you describe, it's just limited to a more specific range, and don't forget that unlike the car anology, you also have the gages with the lights.


Darlene

Decodiver

Phi is right here IMHO. I like the HUD on the Meg because it gives me my real time PPO2 for each cell and like he says it is constantly communicating.

I personally think the Vision HUD is not all that good at all, I remember when we were diving the units at Culdrose and I pointed out to Martin that I had a problem seeing the HUD and his answer was that I needed to change my mask, which was quite frankly utter rubbish.

I also like the Boris HUD, but as a pure PPO2 indicator the HUD on the Meg cannot be beaten.

Cheers,

Dave Cooper.

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divetheworld

I have to say that I see both sides of the discussion here. The HUD as another form of PPO2 monitoring is admirable and has a definite use.
Personally, I like the simple green-OK flashy-Bad type indicator.
Perhaps a meeting of philosophy would be in order. Such as solid green when in the good band and progressivly faster flashing of two other colours for high and low. This would allow you to control the PPO2 within an acceptable band but you would not know th eexact figure you were working on. For that, I like to look at my displays!

Happy new year to one and all.


Brent

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