My phone's got some neat gimmicky features like being thick as a brick, and having a FLIR thermal camera built-in. It does get the job done, but it is working with a pretty well out of date circa 2016ish middle of the road generic Android chassis and software. Beyond the predator vision it's pretty light in the bells and whistles department.
One absence is any ability to stop charging itself once full. An annoying notification to the user asking to unplug is plan (A) right now.
This project has two main components:
1. "Smart" charger based on Itsy Bitsy nrf52840 and a TPS22917 load switcher breakout. Frankensteined together with one of those power only USB cables that are so often a source of frustration. Was I just looking for an excuse to cut one up to exact some revenge? No comment.
2. An Android app that communicates via BLE to the Itsy Bitsy nrf52840 to tell it when the battery is full and thus request that it shut off the power coming in to the phones USB charging port.