Building a dive computer for a school assessment

[KeithG]

...
Regarding a school project: I think a dive computer is a bit to ambitions (since it also involves a lot of questions beyond programming like: How are you planning to make a box that is try and pressure resistant while having sensors exposed to the outside and also a way to recharge it).....

for me, this is actually the most interesting part of the project.
i would skip the "dive computer" portion as trying to evaluate the algorithm would be problematic. an automatic electronic bottom timer / depth guage would be sufficient to demonstrate / evaluate as a class project.

a physical design based upon the uwatec aladin (oil filled) should be fairly easy to achieve.

 

[atdotde]

In that case, I would suggest another project: There are already so many dive computers/electronic depth gauges. But what would I would like to see would be a data logger for cylinder pressure: Small enough it attaches to the first stage of your cylinder (like the radio pressure sensors) but without the need of a hose or radio connection. Just for logging your air consumption. You would later read it out together with your dive computer (for the depth profile), the synchronization of the two devices would be time based. The user interface could be minimal, you don't need contact to the water.

Some time ago, I seriously thought about building this myself but dropped the idea upon finding out that the high pressure sensor that would be needed by itself has a price tag of about 120-150$ and my estimate was that this would be an interesting device for about that price (but then with electronics --- sufficiently cheap usb data loggers are available --- and housing).