of battery + powerboost + softpower-circuit

the breakoutboard is a cheapish chinese import, with a slightly different wiring for the backlight - the important part: the display is the same as in adafruits 2.2" pitft hat (and their 2.2" spi display breakout).

hence it is easy to get it up and running following these instructions:

https://learn.adafruit.com/adafruit-2-2-pitft-hat-320-240-primary-display-for-raspberry-pi/easy-install