I worked on the inductive charger, first making my own coil, then trying on some coils I acquired for more testing. I first calculated that the resonant frequency would be around 24 kHz, with the inductance of 43 microhenries in series with a capacitor of 1 microfarads. However, experimentally, I found that the real resonant frequency was very difficult to measure accurately as simply switching the direction of the probes would change the frequency at which I measured the highest output voltage for a given 5v input. Eventually, I settled on a ~41kHz resonant frequency for the inductor, which gave me an output voltage of ~3.4v (with a 5v input), which is close to the charging voltage for our planned small LIPO batteries, but I believe more investigation is required for the strange resonant measurement behavior.
We are mostly on schedule, having ordered/acquired the experimental parts needed, but the strange resonant behavior did put us a little behind schedule for proof of concept, which I will work on more with Korene next week to resolve. Asking staff may be an option as well.
In the next week, we will finish the proof of concept and create the circuit that integrates and stabilizes the magnetic charging for integration with the boards *when* they get here. (To be clear, the boards will likely not get here next week).