Hi… you could use a micropower comparator as a set-reset flip-flop. You’d need a SPDT center off momentary contact switch to provide the set (for on) and reset (for off) signals. By adding another 100K resistor to the reset input, you could drive that with the Propeller output to provide a processor controlled off switch. The reason for using a comparator instead of a logic gate is that the comparator can run off a much higher unregulated input supply voltage (up to 15V in this case).
How does the device need to be turned off whether after a fixed time since it is power ON or idle or if the battery drained to a voltage limit?
Refer: https://mechatrofice.com/circuits/555/automatic-power-off-circuit
Hi… you could use a micropower comparator as a set-reset flip-flop. You’d need a SPDT center off momentary contact switch to provide the set (for on) and reset (for off) signals. By adding another 100K resistor to the reset input, you could drive that with the Propeller output to provide a processor controlled off switch. The reason for using a comparator instead of a logic gate is that the comparator can run off a much higher unregulated input supply voltage (up to 15V in this case).