I am trying to design a circuit that will completely turn off the Adafruit Powerboost 500 (by connecting the ground and EN pins) automatically. As part of this, I have come up with the attached circuit. I have very little experience with electronics, but my reasoning is as follows:
When the battery is first connected, the EN pin will be grounded and the powerboost will be off. Upon pressing the button, current will begin to flow and the transistor will be inhibited, so the device will continue to operate.
If this circuit works as I expect, I will add a microcontroller between the transistor and 5V pins, allowing me to cut power automatically when a certain event is triggered. This will require pressing the button again to turn on the circuit.
Powerboost manual: https://learn.adafruit.com/downloads/pdf/adafruit-powerboost.pdf