I'm looking at making a dive computer. The commercial ones are usually just a wrist-mounted screen that can display your depth and some other statistics, used when underwater diving. I've drafted a list of intended features and parts below. How feasible is it to build one myself?
- Timer for the diver to know how long they've been under (just a basic real-time clock, DS1207?)
- Alarms that can be set to go off at different times or depths (just a piezo i guess?)
- Temperature and depth (found this little gem, also has gyro and compass! pretty steep though...)
- Heart Rate sensor could be helpful; I probably won't add one , but if I did would this work? (Sparkfun & Polar T31 transmitter)
- Display--something high-contrast, low-power, no frills (maybe this?)
- Battery(ies)... how should I power this? rechargable? disposable?
- Of course, a microcontroller to coordinate reading the sensors and displaying them as necessary
For the housing, I'm thinking I'll wire it all up into as compact a brick as possible and put it in a cheap water-proof case, and then fill with mineral oil (so the "seal" is just keeping oil in and water out). Though, the depth sensor would have to be mounted outside, which could be problematic.
If it ends up too bulky for wristtop, I guess I'll have to find a way to mount the display in a waterproof case and run some wires up the arm to the rest of the components, probably mounted on the weight belt somehow.