Platform for every kind of project: independent intercom, remote toy, drone, and even a new Mars rover.
A detailed description will be available soon... DEMO: https://www.youtube.com/playlist?list=PLBDOR9ZqNeNpt7bb4EgzuAOABzgbZ3tNt
The most important assumptions of the project are: low price of components, simplicity (hardware/software), reliability, versatility.
Solar panel and battery may be smaller or larger, but the principle of operation of the system is to be the same)