pDeco - Windows CE decompression software

This software is currently undergoing testing prior to the first release.

Watch this space.

Warning: Decompression diving is a dangerous sport and decompression theory is still evolving. This software implements current decompression algorithms - these algorithms may be incorrect, or may be incorrectly implemented within this software. You should not use this software for dive planning, and you should ensure you are suitably trained in decompression diving and mixed gas diving before undertaking these activities.

pDeco is a decompression planning tool for the PocketPC. It implements the Bhulman ZHL-16B or ZHL-16C decompression algorithm with any mix of oxygen, helium and nitrogen, and supports gradient factor conservatism.

pDeco also includes tools to calculate gas blending. Two calculations are available - calculate the desired fill based on empty tanks, or whatever may exist in your cylinders following a previous dive, and the mix calculation from a partially filled cylinder with an air top.

pDeco supports multi-level dives, with up to 5 weypoints possible per dive, and up to 5 decompression mixes able to be used.

By pressing on the dive plan (upper) part of the main screen, the weypoint dialog will be presented. This allows you to enter the details for the particluar portion of the dive, such as depth, time, and gas mix. After you've entered the depth and time, you can press the 'Auto Mix' button, and pDeco will calculate the correct mix to provide the desired END and PPO2.

By pressing on the deco gas part of the main screen, the deco gas editor will be presented. This dialog allows you to enter the decompression gas information, such as gas mix, and switch depth.

Once either a weypoint, or decompression gas has been entered, it can be edited or deleted by clicking on the required line. This will present the edit dialog, and the 'Delete' button will also be available.

Dive Options

The following options are available in the dive options dialog -:

Stop at gas change	Allows you to force a minimum stop when you change deompression gas mixes. For example, if you want to for a minimum of 5 minutes when you change to 50% O2 at 21m, then specify 5 minutes here.
Gradient factor (Lo)	Specifies the gradient actor for deep stops. A lower number here will generate deeper stops.
Gradient factor (Hi)	Specifies the gradient actor for shallow stops. A lower number here will increase the time spent at the shallow stops.
Last stop depth	You can specify your last stop to be either 6m or 3m. Making your last stop at 6m generally makes boyancy easier, however it will increase the decompression time slightly.
Descent rate	Specifies the descent rate (meters per minute).
Ascent rate	Specifies the ascent rate (meters per minute).
Descent immediate	If this box is checked, pDeco will ignore the descent rate setting and start your dive immediately at the bottom depth. This will increase the decompression very slightly as more time is effectively spent on the bottom.

Gas Blending Tools

Two tools are included to perform gas blending calculations. The first tool will calculate the mix instructions for obtaining a particular gas mix, either from an empty cylinder, or a partially full cylinder.

The second tool will calculate the mix that you would get if you topped off your partially empty cylinder with air.

Input data	Allows you to specify the initial gas mix in the cylinder. If you're mixing an empty cylinder, set the pressure to 0.
Output data	Allows you to specify the required gas mix in the cylinder.
Mixing information	Once you press the Mix button, the blending instructions will be displayed. Should the tank need to be bled down, this will be displayed in the 'Air' data.

Input data	Allows you to specify the initial gas mix in the cylinder.
Output data	Allows you to specify the required fill pressure in the cylinder. The percentage gas mix settings will be calculated when you press the 'Mix' button.

Software and Installation

Currently only the ARM version is available. This version will work on most new Palm computers (e.g. iPaq).

PocketPC (Palm PC 3.00)
ARM	pDeco-PPC300-ARM

Installation Instructions

Unfortunately there is currently no installation program for the software. This is something I want to address in future, however for the moment the installation needs to be done manually by following these steps -:

Download the correct file for your computer from the table.
Unzip the EXE file from the installation ZIP file.
Bring up the Microsoft ActiveSync window. This can normally be done by double clicking on the icon in the task bar.
Click the Exlore button.
Change directory to the \Windows\Start Menu\Programs directory.
Copy the EXE file to the Palm device.
Copy your LOG file into the \My Documents folder.

Note that some directory names may be different for different languages.

visitors since May 2002.