PastoDeco 4.4 new functions

[TheSnake]

How does it determine max bottom time?

I ran a plan using a single deco gas. Back gas in double HP120s. Deco in a single AL40. I told it to determine max bottom time. It said 27'. So, I changed my bottom time to 27 and re-ran the plan.

It gave me a gas usage of 182 cu-ft of back gas and 23 cu-ft of deco gas. What I expected was for either the back gas to be somewhere near maxed out (i.e. close to 238 cu-ft, which is what PD says is the max for those cylinders), OR the deco gas to either be close to 40 cu-ft OR be close to, but less than 20 cu-ft.

My training is to plan for using half or less of my deco gas, so I would want the "Max Bottom Time" calculation to optimize (in this case) for deco gas usage of 20 cu-ft or less. A plan that calls for 23 cu-ft is unacceptable.

Thanks in advance for any light you can shed on this.


Also, a bug report. This has been like this since before v4.4, I just never bothered to report it.

I'm running PD on an Android tablet (Samsung Galaxy Tab S2 9.7). I use it in Portrait mode.

The problem:

- I run a plan.
- I tap View Text Plan.
- The text version of the plan displays, but it only uses roughly the top half of the screen. So, I have to do a lot of scrolling to see the whole plan.
- I tap the white/red X in the upper right corner to close the text plan.
- I tap View Text Plan again - going right back into the screen I just left.
- On the second entry into this screen, the text version of the plan displays as I would expect it to - using the whole screen (except, of course, for that little Contact dialog or whatever it is that is always at the bottom).

Hi,
max bottom time is calculated in order to leave in each tank ( bottom gas or deco gases ) at least the reserve level as defined in Settings menu.
By default, it is on 50 bars/725psi.
Note that you can set reserve level as fixed pressure or as a percentage of total gas.
If I understood your need, you must set reserve level as percentage and set it to 50%.

For the second "problem", effectively the text plan window is small, to fit also on small devices and leave space to mail send function fields and buttons.

I will try to add an "expand" button, or something similar, that allows text plan zone to take all available space on the screen ... and will publish an update this week-end.

 

[TheSnake]

Let me know if it works for you ( max bottom time with half tank reserve )

 

[stuartv]

For the second "problem", effectively the text plan window is small, to fit also on small devices and leave space to mail send function fields and buttons.

I figured it might be that. But, that doesn't explain why I go into the screen the first time and the text window is small, then I just hit X to close it, then tap View Text Plan again immediately, to come right back in and the second time the text window is bigger.

I had a feeling there was something in the settings that I needed to look for regarding calculating max bottom time. I will have a look.

 

[stuartv]

I just looked at the settings and Max BT calc again.

The problem is Gas Reserve is applied to all cylinders. I think it needs to be per cylinder. I want my deco bottles to have a 50% reserve and my back gas to have a (for example) 500 psi reserve. Or maybe a 1200 psi reserve (i.e. 33%). Or whatever. The point being it will often be different than what I want for deco gas reserves.

If I set reserve to 50%, then it does plan to use no more than half my deco gas, but it makes it plan for only using 1/2 my back gas.

The only way to really have it do what I want (as it is currently implemented) would be to set it for a 500 psi reserve and then manually calculate what 1/2 my deco gas is + plus 500 psi, then fudge the deco cylinder spec to match this fudged number. So, set my AL40 deco cylinder to a working pressure of 2000 (i.e. 1/2 is 1500 psi, plus 500 psi). With the reserve set to 500 psi, that would let it calculate to use no more back gas than would leave me 500 psi, and use no more than 20 cu-ft from an AL40.

But, that seems like kind of a kludge. I shouldn't have to fudge my deco cylinder spec every time I want to change the Reserve setting for my back gas. It seems like it would be better to just have the Gas Reserve setting be a separate setting for each cylinder configured. Either that or have 3 Reserve settings - one for bottom gases, one for deco gases, and one for travel gases. You have separate ppO2 settings for bottom and deco (and I'm not sure which limit would be applied to travel gases, but I assume bottom). Why not at least have separate bottom and deco limits for Gas Reserves, too?

BTW, it is GREAT that you have added this feature! Hopefully, it won't be too hard for you to make it just a little more useable.

Another question: if I put in 2 legs for my bottom time, how does it calculate max bottom time? Does it just treat one of them as variable and solve for the maximum value for that one leg? If so, which leg does it solve for? The first leg? The last leg? The deepest leg? Or does it solve for both legs to be equal time?

A dive I'm trying to plan would involve a wreck where I want to dive to one depth, swim along the wreck at that depth, then ascend to a higher point on the wreck and swim back. So, in that case, it would be two legs where I would like the time for each leg to be the same - and, of course, the maximum possible.

 

[TheSnake]

I just looked at the settings and Max BT calc again.

The problem is Gas Reserve is applied to all cylinders. I think it needs to be per cylinder. I want my deco bottles to have a 50% reserve and my back gas to have a (for example) 500 psi reserve. Or maybe a 1200 psi reserve (i.e. 33%). Or whatever. The point being it will often be different than what I want for deco gas reserves.

If I set reserve to 50%, then it does plan to use no more than half my deco gas, but it makes it plan for only using 1/2 my back gas.

Hi stuartv,
I made some changes as per your request:

separate setting for bottom/travel gases and deco gases.
Here for Bottom gas I want 60 bars/870psi reserve and for Decos 50% of carried gas.

then I launch max bottom time calculation and it says 14 minutes.

launching runtime calculation with 14 minutes I have bottom tank with 64 bars/928 psi residual gas ( > 60 bars ) and
deco tank with 101bars/1465psi residual gas ( >=50% of total gas ).

 

[TheSnake]

The text version of the plan displays, but it only uses roughly the top half of the screen. So, I have to do a lot of scrolling to see the whole plan.

Now I changed Text Runtime display.
Send by email options are hidden and shown if expand button is pressed, so RunTime zone take near all available screen space ( except for buttons at the bottom ).

 

[stuartv]

Awesome, Antonio! The updates look great! I am looking forward to being able to update my copy from the Play store. No update is showing as available to me yet.

I'm still wondering about this question: How does the app determine which leg, in a multi-leg dive, to treat as the variable for time, when it solves for the maximum? First leg? Deepest leg? All legs equal time? Something else?

Thank you for the great work and such quick turnaround!

 

[TheSnake]

Awesome, Antonio! The updates look great! I am looking forward to being able to update my copy from the Play store. No update is showing as available to me yet.

It's normal. It's not already posted on Stores.
I will post you how multilegs works then I will validate the release.

I thinked that in case of multilegs, I maintain the same timings ratios. E.g.: you plan a dive on a wreck 8 min. at 95 f + 8 min. at 125f, it can tell you that you can stay 20 min. ( 10 at 95f and 10 at 125f ).

Otherwise if you plan the same dive but 10 min at 95f and 6 min at 125f, it tells you that you can stay 20' ( 12 min at 95f and 8 at 125f ). It increases each leg equally.

 

[stuartv]

It's normal. It's not already posted on Stores.
I will post you how multilegs works then I will validate the release.

I thinked that in case of multilegs, I maintain the same timings ratios. E.g.: you plan a dive on a wreck 8 min. at 95 f + 8 min. at 125f, it can tell you that you can stay 20 min. ( 10 at 95f and 10 at 125f ).

Otherwise if you plan the same dive but 10 min at 95f and 6 min at 125f, it tells you that you can stay 20' ( 12 min at 95f and 8 at 125f ). It increases each leg equally.

That sounds great! Thank you again!

 

[TheSnake]

Ok. It's done.

It looks like this:

I will create packages and publish Win/Mac/Android/iOS versions this week-end.