I want to speed up the ADC, because it takes me about a milisecond to sample my entire sensor array.
So, you have an array of eight or nine sensors?
You're still sampling every two millimetres.
The analogRead (you have the source) splits neatly into four sections:
- Setup input mux
- start conversion
- busy-wait for conversion to complete
- read result.
Eliminate 3), and you're probably a good way to doing what you want.
Or think about using the end-of-conversion interrupt.