How to select a different Thingspeak Server?

[bcraigie]

Needs documentation on how to choose to use a different Thingspeak Server (for example one you have installed yourself on your own Linux Server).

[bcraigie]

The answer is simple:

Instead of
ThingSpeak.begin(client);

Use:
ThingSpeak.begin(client,"ip address", port);

For example:
ThingSpeak.begin(client,"192.168.0.100", 3000);

Replace the IP address and Port values above with your own Thingspeak Server values.