## AD conversion

This library is really minimal : I wrote it for my own needs, so the source code must be edited to be adapted to yours.

1. `void AD_init()`

   Initialize AD conversion system for 16MHz processor. AN0,AN1,AN2 and AN4 are used as analog inputs. AN3 is used as voltage reference input.

2. `unsigned long AD_get(unsigned int ch)`

   Starts AD acquisition and conversion on channel `ch`. Channel number can be `0` (`AN0`), `1` (`AN1`), `2` (`AN2`) or `3` (`AN4`).