Turning my GPS logger shield off and on
Yes, it is as simple as that.

However, since the pin is pulled up already you could also do this:

pinMode(pin, INPUT);
digitalWrite(pin, LOW);

// Turn off
pinMode(pin, OUTPUT);

// Turn on
pinMode(PIN, INPUT);


That then emulates an Open Drain pin which means you're not actively driving the pin when turned on, only when turned off.

Personally I prefer system that are active low not active high, and are pulled down by default (normally off) so that you don't waste power driving the pin in order to save power (it's kind of silly really) - you drive the pin to turn on and let the pin float to turn off (especially good with deep deep comatose sleep on some MCUs where the IO pins all switch off).

However the designers of this module decided otherwise, so you're stuck with driving the pin LOW to make it sleep.