After I get the idea set for a project like this, I like to scavenge for parts or order some so I can start testing the various parts out before I start designing circuits and programs. I think it's a good way to go, as you get a feel for unfamilliar equipment before you cement it in place and find out you have not made enough allowance for it.
That is normally. This time however I start the concept while stuck on an oil drilling rig for a month. So this time I will start with circuit boards in Fritzing and basic modelling in FreeCAD. Hopefully I can get enough literature to base decisions for pumps on. And all the while I have internet so slow, I can't even load a speedtest. So this may add a major challenge in submitting my video and logs, as well as in getting literature.
Another challenge I face with this project, is camera's are only permitted inside the rooms, and here people are sleeping in shifts, so recording the audio track of the video will be hard. I blame procrastination!
Onto the normal kind of challenges faced in a project. Shops selling robotics or less-than-general electronics are kind of expensive in South Africa, so sourcing the dosing pumps at a decent price will be interesting. I'll keep my eyes open on electronics that may contain these pumps though, but otherwise I will just have to go ahead and order some from China.
Driving the pumps will be down to H-bridges to provide bi-directional drive. Charging the LiPo is basic so I'm not worried about that. Getting the whole concoction to float might be interesting. Might laser cut some pieces to keep everything in place and dry. Oh keeping the dry bits dry.... That might be the biggest challenge. For now I think there is enough physical separation, but as these things go, it changes over time, and before I know it, my laser diode swims with me...
Then the biggest challenge of them all. Sitting still for long enough to get some work done.