hw OS Tech 3.07 - Running simulator in large font mode

[Dragan]

Hi,

I've stumbled over a problem that I think is related to the simulator in 3.07 Tech, but I'm not fully sure and I haven't been able to test live yet on my OSTC 2.

When running simulator with the large font setting enabled, I get a small green&yellow text on top that say e.g. 21m. This number seem to match the current "set value" for the simulator, i.e. when starting the simulator with default settings a dive targeting 21m is launched. From second zero, the green/yellow text show 21m while the actual depth is slowly increasing from zero to 21m.

When descending/ascending, the green/yellow text is updated to the new depth "set value" and after a while the current depth has been adjusted.

That said, what I fail to get working (at least in simulator mode) is to show both Max depth, Total average and Stopped average on the same display.
I need to choose between Total average and Max depth.

When using the unit with normal font size, depth and max depth is shown on top and total average and stopped average is shown in the middle.

See links to screen shots below...

Is this merely a simulator bug or is the same problem also present in water when using large font mode? I can live with the simulator showing strange values, but I would surely like to be able to use the grumpy-old-diver-mode in the water...

Best regards

/Jonas

Large font in simulator

Standard font in simulator

[Ralph]

Hi,

it's not a bug or a problem - it's as by design!

The screen layouts 'normal' and 'large' are the same in simulator and in real diving. With the small add-on of the target simulated depth shown in tiny digits above the depth when in simulator mode. You can select your prefered layout under Settings -> Display Settings -> more -> Layout.

The 'large' layout is made for a cleaned-up screen showing only the most relevant data. it on purpose does not show max. or total avg. depth. These can be optionally viewed using the 1st custom view. Where you set your default layout, you can also select which 2nd depth shall be shown: max.depth or average depth. Additionally, the stopped avg. depth is visible on the right of the 1st custom view regardless of layout and 2nd depth display selection.

BR
Ralph

[Dragan]

Too bad...

I really enjoyed experiencing the large font view due to reduced eye performance, but I don't really see myself diving without access to both max and total average depth at the moment as I consider them very relevant.

Fingers crossed that the standard layout is big enough for me, at least the characters are bigger than my previous unit and that's a good start.

[Ralph]

Well, you still have the resettable pair of time & avg depth in the middle & right of the 1st custom view. As long as you do not reset the timer and thus the related resettable avg. depth during your dive (menu action), it will serve your purpose!

Ralph

[Dragan]

Repeated re-sets of average depth is a standard solution for keeping track of bailout range when doing advanced CCR cave/mine dives. That's why I preferably have access to both total average and stopped average. Stopped average for bailout range, total average for on-the-fly deco calculations to be able to double/sanity check the deco profile generated by the computer.

To me personally, I could probably remove 15 other items from the "scrollable" views without missing them.
Fully understand that this advanced type of average depth usage is far from what most users do.

I will simply have to settle with standard layout instead and hope that my eye sight does not get worse...

/Jonas

[Ralph]

Hi Jonas,

thanks for these details. I am not familiar with the way you use avg depths for checking deco, anyhow, just to ask: are you aware of the OC bailout gas needs calculation available on the OSTC now? Currently it only calculates an open water emergency ascent, but i am thinking on implementing a cave mode, too.

best regards
Ralph

[Dragan]

Hi!

For deco sanity check, I typically use one of the many guidelines for on the fly deco calculation and compare it with the profile generated by the computer. There are multiple versions available and I've changed models over the years but the one I've been using for the last couple of years is the GUE model.
A simple table that handles NDL-times for different average depths and guidelines of how the deco is effected when spending more time than NDL on a specific average depth. Simplified you have one table for each standard gas mix. Seem complex at a first glance, but really easy once you get used to it.

With regards to OC bailout calculations:
I have actually provided a suggested algorithm for a cave bailout function many years ago. My team even managed to finalize the first part of the implementation on the older versions of OSTC which I've been using for many years before my Mk2 crapped out on me and then during last year before my older generation OSTC 2 died.
Would really appreciate re-introduction of that feature in new generation OSTC

[s]The old forum seem to be offline now, but if you have access to a backup the algorithm was discussed in a thread on http://www.heinrichsweikamp.net/forum/r ... 0#msg-6580[/s]
Edit: found the thread on new server:
https://forum.heinrichsweikamp.com/read.php?2,6472

From the top of my head, the simplified solution that was implemented was to add a configurable SCR (e.g. 30 liters per minute to compensate for CO2 problems) and then continously calculate used gas based on the actual depth (or actually the pressure at that depth of course) in order to be able to present bailout requirements in liters.
We also had a setting that would change color of the calculated value from OK to Warning when used gas was more than the configured number of liters, e.g. 2200 for an 80 cuFt stage.
Calculation was reset every time the stopped average depth was reset.
Based on this value it was easy for a thinking diver to verify that the plan from the surface was still correct and to make sensible decisions during the dive.

The forum thread involve even more complex solutions to be able to support re-calculations during complex navigation dives, but in the end I think the simplified version is more than ok.

If you want more input from cave perspective, I'm more than happy to assist! I could add more items from the past, but it's not in the scope of this thread
Hint: TTS if you invert the dive profile from an arbitrary point in the dive would be awesome! Requires a lot of CPU and memory which was for sure not present in Mk2, but potentially possible now?

This should probably be in a separate thread...

/Jonas

[Ralph]

Hi Jonas,

i wasn't aware of this old thread as i'm with OSTC programming since only about two years. But many of the ideas stated there are actually implemented in the firmware now or are currently in work on my side:

The gas needs calculation is a projection of the gas amounts needed to do an open water (i.e. vertical) ascent after staying at current depth for x minutes longer, with x being the configured fTTS time. This time of x minutes is meant to be a buffer to answer either the question "will it be ok to stay a little bit longer", or to figure in the time it takes to call the dive and send an SMB in an orderd manner without running dry on gas later. As i'm a CCR diver myself, in CCR mode the gas needs calculation switches to OC (bailout) gases, so i made it calculating a true bailout ascent.

The gas needs are converted to bar by the configured tank sizes, to give numbers easy to understand and relate to the SPG readings. Furthermore, attentions and warnings are given as soon as a gas becomes short in supply, so another idea from the old thread has become reality now.

My current brew is on calculating gas needs in a "cave return" mode, that is not doing a straight vertical ascent but a true back-tracking along the depths that have been recorded during the dive. Logically, with doing in-between deco stops whenever following the (inverted) depth profile hits a deco ceiling. This will also work when the recorded profile has multiple descents and ascents, requiring multiple individual deco-stopped ascents on the way out. I belive that's very close to your proposal... May i ask you to email to HW to get in touch by private mail? Then i could give you some more information on the implementation and maybe you like to do some testing...

BR
Ralph

[Dragan]

Ralph,

There's a big smile on my face writing this.

If you actually implement according to my understanding of your description, OSTC will for sure stand out in the crowd. No other dive computer on the market that I'm aware of (and I've really been trying to find alternatives) is even close to having support for "cave TTS" and/or cave bailout.

I've sent an email to HW with my contact information and I'm more than happy to assist with testing!

/Jonas

[Arno]

Ralph Wrote:
-------------------------------------------------------
> .....Then i could give you some more information
> on the implementation and maybe you like to do
> some testing...
>
> BR
> Ralph


I think there may be more cavedivers interested in more information (I for sure am one). So if the information you would like to share is of interest to more cavedivers then please also share it on the forum. The Cave TTS and gas calculations are a really nice feature!

[Ralph]

Hi Arno,

thanks for your interest! Please also establish PM contact with me via email to HW if you like to particiate in the development and testing of the cave mode. The code and the underlaying algorithm is in alpha state right now. Therefore i do want to give it only to known persons at present time, to avoid any possibility that unaware people use it by accident, not knowing what they are doing and then eventually face the dark lord...

thanks for understanding,
Ralph

[Arno]

Ralph Wrote:
-------------------------------------------------------
> Hi Arno,
>
> thanks for your interest! Please also establish PM
> contact with me via email to HW if you like to
> particiate in the development and testing of the
> cave mode. ......

Mail just sent. Thanks in advance. Looking forward to helping you in further extending the possibilities of the computer.