I hope to use a piezoelectric button to harvest and produce a sufficient energy burst to power ON and bootup a MSP430 for a few ms enough to update a simple data structure (e.g. two integers stored in nonvolatile memory e.g. FRAM) and then power OFF. Note that the MCU will be completely dead before the piezo button press. This updated data structure will be used later on when sufficient energy is available to do more complex tasks (e.g. perform computation/send signal over wifi etc.).
Assume: The FRAM-range MSP430 (e.g. MSP430FR59xx) with lowest clock frequency (32kHz), min. operational voltage 1.8V, lowest power mode that can do the above operation. I'm not sure how much current the above operation (integer updating) would require, but I assume it's under 0.5mA, lasting for under 10ms. Assume there is another solar energy harvesting element that is charging up a secondary energy buffer (e.g. a largish capacitor) to do the complex MCU actions mentioned above.
I guess the objective is to see if there is a way to capture user input in a quick and dirty fashion and react upon the input later, when sufficient energy is available from the secondary energy source.
Can a piezoelectric sensor button or a capacitive touch sensor button produce enough energy to perform the above?
Assuming (1) is possible and there are 2 such buttons (A and B), then can the MCU obtain knowledge of which button was pressed and gave it power?