I've been trying to do an honest update on the progress of the project. It's been slow going, but there has been LOADS of progress. 

At the moment I'm in the trial and error phase of designing a controller board.

What the controller board does:

• Control
• UI
• Power management

I'm about a month away from getting back into the water. Of these three aspects, the user interface has taken most of the time. 

UI

This has been taking most of my time. If you can avoid it. 

How users interact with a device is a massive study on its own. I've been juggling giving the users many control options while keeping it as intuitive as possible. This has taken many iterations and hardware changes. It's hard to draw the line between what's possible and what's practical. I think I've finally struck an acceptable balance in practicality/functionality.  At the moment users can set up the device with a dial and a tiny screen for feedback. 

Control

The PCB design & etching process is quite rewarding, but it has been a bit of a slow slog. I've made many mistakes in the designs and I'm close to creating a 4th iteration of the board which will hopefully be the last version before I start adding some extras. The design also keeps changing as I learn more about more suitable parts.

Power

Power management has been a real eye-opener. There is a lot of control I need to add to reduce the overall power consumption of the project. The power banks I've been so excited about has proven to have some real limitations. This is worth a log in the future, but I've basically decided to scrap them. In short, they are too smart for their own good. 

I've also come to the conclusion that the project is at a cross-roads. I see this splitting off into two branches. One being the quick and easy one, that folks can build on the cheap and get in the water fast (with some limitations).  Hopefully I'll finish a how-to guide for this in the next few weeks.