As with all wearable technology projects I’ve worked on, power is one of the big challenges. There are all sorts of really cool things you can make, but as soon as your system requires 12V to run, it becomes unwieldy and not really wearable unless it’s a backpack to start with.
here is a fairly compact 12V battery pack, I found on Amazon, but it still weighs almost a pound. Doable for some applications, but wouldn’t work to wear on the forearm and at $34 each, makes it difficult to have a couple extra on hand
In the past, I have been very pleased with Sparkfun’s 5V rechargeable power bank for both function and affordability. It is compact and light weight, comes with a cord to power your project and recharge the battery. Additionally, the power button on the battery can double as an on/off switch for the entire project.
The big problem with the initial prototype is that the solenoid valves needed 12V to open and close. With a bit of digging and research, I was able to find some 5V solenoids as well as a mini air pump, and ordered some for the next iteration of this project.
For my initial prototype and testing, I was using an Arduino Uno and a Sparkfun RedBoard for the micro controller, however, I’m going to switch to a much smaller ProMicro board now that the code has been tested.