Question: I want to have the Pi create its own Access Point for other devices to connect to,
but only when the Pi is out of range from a decent connection to a 'base / home' router? 

I want to be able to have the Pi at home, and connect,
but when I'm out and about, and have the Pi on a mobile connection, I want it to create the Access Point, or Wifi Hotspot.

Answer: 
This is a very common need. There are lots of solutions out there, and lots of tutorials (that I find to be dated and inaccurate the older they are).

The solution I have been using with success is one of the Auto Hotspot scripts from [Raspberry Connect](https://www.raspberryconnect.com/projects/157-raspberry-pi-auto-wifi-hotspot-switch-internet). Look at the different hotspot articles on that page.

Alternative options that I have not tried but came across in my search include those below; the -turnkey one seems to be well documented.

* [raspberry-wifi-conf](https://github.com/sabhiram/raspberry-wifi-conf)
* [raspberry-pi-turnkey](https://github.com/schollz/raspberry-pi-turnkey)
* [kupiki-hotspot-script](https://github.com/pihomeserver/Kupiki-Hotspot-Script)
I tried the solutions above with some success but nothing as good as I wanted. I found ComitUp as being another method of doing this. It was a lot easier.

<https://davesteele.github.io/comitup/> (Thanks to Dave!)

> 
> Comitup is a software package that provides a service to establish Wifi networking on a headless computer (that is, one with no video, keyboard, or mouse).
> 
> 
> The Comitup Image is a microSD disk image for the Raspberry Pi 3, providing an operating system with the comitup service included. The Comitup Image is an extension of standard Raspbian OS...
> 
> 
>