I am trying to connect the STM32 bluepill board to a lithium cell as the main power source, and to the output end of a solar charger. The idea is to have the solar as a backup during the low sun hours, if for any reason the cell was not charged then the STM is not disconnected. I know this is achievable using Arduino, but for reasons beyond my control I must now shift the development to an STM32, is this possible? Can the STM32 be powered from two independent power sources. The datasheet is quite dense, and I'm frankly stuck. I attached a sketch showing what I want the circuit to achieve.
The solar charger permits two outputs, one for load (connected to STM) the other to the cell
The STM will be connected at all times to the cell and solar charger output
The STM will not be disconnected from the lithium cell when the cell is being charged (I assumed the STM is a negligible load-could be wrong) nor will it be disconnected from the solar charger output-Not sure if this would result in some technical conflict.
I have concerns regarding the authenticity of my STM bluepill, considering that I'm outside the US/EU there is a fair chance it's a clone (I bought this under the assumption it is an original) I've read online that the internal voltage regulators fail quickly not sure if my proposed setup of two independent sources could accelerate the damage.