Dive Computer Technology?

Discussion in 'Computers, Gauges, Watches and Analyzers' started by gcbryan, Aug 30, 2009.

  1. gcbryan

    gcbryan Orca

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    This is an open ended question for anyone with the knowledge to answer...

    1)What are the limiting factors preventing a Liquivision X1 type of display from being used in hockey puck $400 type of computers? I assume cost, battery considerations, and perhaps size of the enclosure but I don't know for sure. Also what is the chance of the component cost coming down dramatically?

    2.What are the memory requirements/limitations for entry level hockey pock computers? How feasible would it be to have display user controllable much like you can control your "desktop" with Windows.

    3.How hard/what cost considerations would there be for entry level computers to have software choices so that you aren't stuck with Buhlmann derived algorithms or having to ignore your computer on occasion because what it's recommending is not what you feel to be best?

    Just in general, need all of these features only be in very expensive computers? Is there anything inherent (other than the display question) in these changes that have to involve great cost?

    With respect to the display question if cost is the main issue I'm wondering what the volume differences are between for instance Liquivision and Oceanic. You would think Oceanic would have some volume advantages (but probably not enough at present to be used in low cost models).
     
    Last edited: Aug 30, 2009
  2. fnfalman

    fnfalman Single Diver

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    I'm not familiar with the Liquidvision. I know what it is but I have yet to see how it works. But how much display do you need? You have bottom time, pressure reading (AI computer), depth reading, nitrogen loading, oxygen loading and ascend rate. What else need to be shown?

    As far as selectable deco algorithm, the Oceanic OC-1 allows you to select either the modified Bulhman (RGBM) or the Haldanian algorithm that most recreational computers use.
     
  3. Kern

    Kern Loggerhead Turtle

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    He's talking about the OLED display


    It uses Buhlmann ZHL-16C, nothing to do with RGBM.
     
  4. TheBigPhillyFish

    TheBigPhillyFish Nassau Grouper

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    The liquidvison are intended for OC technical diving, and CCR's. Unless you intend to get into either one of those, don't even bother. And as far as I am aware of, the Liquidvision does not support air intergration, only offers O2 sensor for CCR.

    It all depends on what your looking for in a DC. By the sounds of it you want a DC thats not so conservative. There is plenty out there to choice from. And another question you need to ask yourself, do you want or need wrist mounted?

    I could list a few to look into:

    Oceanic OC1 is nice it allows the user to switch between two algorithms, and also allows programing of additional safety levels, it also has air integration. It allows 3 mixes, O2 21-100%. Downfall, pricey msrp $1850, $1500 with out transmitter.

    Scubapro / Uwatec Galileo and Galileo Luna IMO one of the better of the recreational DC's. Is wrist mounted and air integrated, offers 3 gas mixes from 21-100% O2, and has an electronic compass, which is considered one of the better on the market. Can also read up to 4 transmitters. This DC also has a very large data logbook. This is a middle of the road DC, the diver can program up to 6 micro-bubble levels for increased safety. MSRP $1350

    Sherwood Wisdom 2 is a console mounted air integrated DC. At this time I personally use this DC. ITs air integrated with quick disconnects. Its a very liberal DC with very large easy to read numbers. The one thing I really like about this DC is the safety stop timer. It is very easy to navigate through the settings. Will do nitrox I believe up to 40%. MSRP $895, you can usually find these pretty cheap around the 400-500 mark.

    Oceanic VT3 is a wrist mounted air integrated DC. This DC offers the ability to monitor 3 transmitters and 3 different nitrox gasses. This DC has a large face for a wrist mounted DC. I have actually tried one of these at an Oceanic event and loved it. This DC also offers a safety stop timer. It has a surprisingly easy to read face. MSRP 999.00

    Aeris Elite T3 is a wrist mounted air integrated DC. This DC also offers the ability to monitor 3 separate transmitters and allows for 3 different gases up to 100% 02. The large face is easily readable. I have also tried one of these, and I put it in the same class as the Oceanic VT3. I believe this and the VT3 actual computer and algorithms are made by the same company just put in different shells and sold under different names. MSRP 999.00

    Other air integrated DC's to consider Oceanic Atom 2.0, Aeris Compumask, Suunto D9 and Vyper, Uwatec Aladin Smart Tech. And also remember there is plenty of non integrated wrist mounted DC's out there.

    I can honestly say if I was looking for a recreational DC right now I think I would be looking at the Scubapro/Uwatec Galileo Luno. I like the features this DC offers, and having an electronic compass is really nice. I also prefer the large square screen to the smaller screens of the round DC watch type. But don't take anyone word for it. Find a local dive shop that carries what your choices are and try them out. Make sure the fit is what your looking for, also make sure they offer safety stop timers, and find out if its conservative, middle of the road or liberal algorithms. I hope this was somewhat of a help! Goodluck.
     
  5. ianr33

    ianr33 Orca

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    Whats this "Liquidvision" computer people keep talking about?
     
  6. mkutyna

    mkutyna Divemaster

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  7. ianr33

    ianr33 Orca

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    Oh ! You mean the LIQUIVISION ;)
     
  8. gcbryan

    gcbryan Orca

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    I think you missed my point. I have several dive computers. I'm wondering if cost and any other considerations will soon if not now make it possible for OLED display technology to be made available in less expensive wrist dive computers.

    I'm also wondering why (memory issues) displays aren't more user configurable...depth on top, runtime below, NDL smaller and over to the side, etc.

    And I'm wondering why there aren't more choices in algorithm so that computers can match dive buddies or desktop software. Really knowing and controlling what is in the computer not just settings to make whatever is in their more conservative....Buhlmann ZHL16C and VPM-B etc.

    I thought maybe some EE's out there would have info on cost for OLED and the feasibility of the other issues I've raised.

    It was more about the ideal (for me) computer.
     
  9. ianr33

    ianr33 Orca

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    You could always program your own computer
    HeinrichsWeikamp GbR
     
  10. gcbryan

    gcbryan Orca

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    Thanks for the link. I hadn't seen that one. Peter Rachow in Germany has a site for a DIY project but the computer is very large and not particularly high tech.

    This one is interesting. It still has a high price tag though.;)...actually I'm not sure what the price is. Is the symbol being used the Euro symbol?
     
  11. Kern

    Kern Loggerhead Turtle

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    OLED displays are more expensive than LCD's. They use more power than an LCD. Therefore battery usage goes up, so power supply requirements go up adding to the expense. There are also longevity issues with OLED.

    If you want to run algorithms more complex than a neo Haldnian type you need a CPU with more power so it can crunch enough numbers to do it in real time, therefore more expense. Such a CPU is not only more expensive in itself, but they require more power, so once again the power supply needs to be increased.
     
  12. ianr33

    ianr33 Orca

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    Yes. thats a Euro symbol.

    I recently bought a Shearwater Pursuit. Algorithm is Buhlmann ZHL-16C . It allows pretty much any user definable gradient factor to be used. That means you can match just about any profile you want with it. I much prefer that to a manufacturers "conservatism factor" (even though it does not have a heart rate monitor ;) )


    Could you hazard a guess as to the likely lifetime of the screen on the Liquivision?
     
  13. kanonfodr

    kanonfodr Loggerhead Turtle

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    I don't mean to be a troll, but OLED displays actually use less power than comparable LCDs because they don't require the battery-crushing backlight that LCDs do.

    That is very true. But I don't see how it would be much of a problem to cut, say, a Buhlmann algo that has been modified for less conservatism and upload it to the computer. Granted, one doing so would need to really know his stuff in several areas to be safe.

    But I believe that the Liquivision gives the diver the opportunity to plan his dive on DecoPlanner and then transmit that plan to the DC, thus the computer and the diver would be on the same sheet of music as far as deco planning goes.

    Peace,
    Greg
     
  14. Kern

    Kern Loggerhead Turtle

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    Not really, when I was trying to find such info prior to making a purchase, I found everything from, OLED's are an expensive piece of garbage that won't last 5 minutes to 20,000 hours. That's not the X1 screen in particular, it hadn't been out long enough at the time, but OLED displays in general. At this date, I can say that there have been some problems with some X1 displays, but I can't tell you what the percentage is.

    As my warranty expired recently, let's just say I hope the 10,000 to 20,000 hours will turn out to be the case.
     
  15. tgsmith

    tgsmith Barracuda

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    I might be missing the point, but I don't get it. Why would you want to import a plan from your desktop planning software into the computer? The point of having a computer is that it's on the fly. Do you mean you define your gases on the PC using desktop planning software and then download this into the dive computer? Or are you actually talking about downloading a decompression plan into a dive computer(Which I can't fathom the purpose of such)? That'd be like viewing a dive table in electronic form that you could have saved $1740 on and just written them down on slates.....

    The only decompression computer I knew of that really needed to have stuff imported into it from a PC was the Cochran using it's "Analyst" software. I know with my Shearwater you can set it up on the computer itself......the only thing it does with my PC is upload the dive logs.

    When a computer doesn't have the requisite brainpower it effects it's ability to calculate a decompression schedule or function at all. Witness the VR3 with it's infamous, "SEE TABLES" message.

    I can't tell you why more computers aren't using the OLED's yet. But I can tell you my Shearwater Pursuit is big, ugly, simplistic, but actually works 100% of the time and costs less than most top-end technical computers. Function over form.
     
  16. tgsmith

    tgsmith Barracuda

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    I just read that and realized I was kind of rambling and incoherent, or completely off-topic to the question at hand. I was trying to say something, but I got lost. :lotsalove:

    eh, oh well. safe diving.

     
  17. giles45shop

    giles45shop Barracuda

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    Just to clarify, you don't import your plan from the desktop to the computer. The Liquidvision running VPlanner Live uses the same algorithm as the VPlanner desktop dive planning software. So if you cut tables in VPlanner, and follow the exact profile of your tables, the computer will provide the same result. If your actual dive is different than the tables you cut, the VPlanner Live adjusts on the fly, just like any other dive computer, but it doesn't lock you out like the VR3.
     
  18. DiveNav

    DiveNav ScubaBoard Supporter ScubaBoard Supporter

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    I don't agree with this statement .... these days you can get an arm16 based microcontroller with embedded memory, plenty of power to run any deco algorithms you want - and more to spare.
    They cost nothing and they consume nothing :D

    Prices are high because volumes are low

    Alberto
     
  19. Kern

    Kern Loggerhead Turtle

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    I don't mind discussion, I don't actually consider it trolling.

    Well, I'm no expert on these things, but when I looked into such things, the consensus seemed to be that OLED need more power than an LCD. Do you leave your backlight on during the entire dive, I cant remember ever turning mine on during an OW daytime dive.

    That is in fact my point. You can load any neo Haldanian such as Buhlmann onto any of today's crop of computers. There are however very few presently with the power to run a fully iterative dual phase algorithm in real time. So if VPM-B using V-Planner is my preferred desktop software, & I want a DC that is capable of running that same algorithm, it need's to have a more powerful CPU to do so.

    Stop believing, start knowing. :) Sorry couldn't help myself, but that's not the way an X1 works.
     
  20. ptyx

    ptyx Manta Ray

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    Not import, but define. So the computer can remind you to switch gas, tell you the optimal ascent rate, etc. Also according to some X1 VPM software FAQ, deco computations are bidirectional in some situations (i.e. knowledge about available deco gases will impact the dive plan before reaching deco).

    From the X1 manual: The OLED display is rated to retain more than half its initial brightness after 40,000 hours of use.

    That could be a big issue for using the technology on mainstream computers: X1 doc says 30h underwater battery time, and it requires an AC adapter for charging. It would be an increase in manufacturing costs (adapter, dock and connectors) and a loss of convenience which is hard to justify.
     

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