I have a design that runs from a lithium coin cell battery with a nominal voltage of 3V but running down to ~2.2V. I'd like to be able to momentarily (~250-500ms) pulse a small Blue LED with a Vf of 3.3V
I am aware of conventional options like voltage converters, the joule thief, etc. but I am looking for a very simple, low cost, and power efficient method to drive this LED with the battery I have. A microcontroller with various peripherals is available on the board.
Any clever suggestions? Is a voltage doubler via microcontroller PWM a reasonable method to drive a few mA?