So, delivery #1 of many arrived today; 3 ESP07-based serial boards.
With only Tx, Rx, power and ground pins broken out, this board is controlled via AT and over a serial connection.
This is perfect for this project - added to the Serial1 port of the Mega it will make wifi comms easy!
I am going to adapt the Arduino sketch of the project I previously shared to process an 'ESP_' command, and forward the following string (which will be the AT command) straight to Serial1.
In addition I am going to write a python based GUI, along the lines of the previous link's C# application. This is to practice writing python GUI apps, and also to write something that works cross platform.
Will post my results Tommorrow, all being well!