There are several tuner projects based on Arduino.  Here is one.

https://hamprojects.wordpress.com/2016/12/31/hf-automatic-tuner/

You can find schematics for almost all the major vendors out there.  The setup / hardware is basically all the same.

The hardware does not seem difficult.  The L match seems to be the most common.  I would use latching relays, so it could use very low power when not tuning, like the Elecraft T1 tuner.  The magic would be in the programming of the tuning subroutines.

Marco - KG5PRT 

On Dec 31, 2017 8:42 AM, "Rod Self" <km6sn@...> wrote:

Hi All,

some time ago I built a single-ended version of Farhan's tuner shown here:

http://hfsignals.blogspot.com/2015/06/a-balanced-tuner.html

It is a basic L network with binary-weighted C and L values, switchable to either Hi or Low Z.

My operational impressions:

1. It is amazingly simple to tune up to an unknown load, and

2. even when the impedance mismatch is severe, switching in another tap of L or C shows easily-readable improvement in reflected voltage, which

3. gives a useful clue as to what to switch next, and

4. it is probably not necessary to use reflected voltage and phase readings- reflected voltage is probably sufficient, and

5. it would be simple to relay drive it and use a Nano to tune it.

So, I decided that when I got around-to-it, I would  automate it with a Nano. It just has not happened yet.

Just some operational feedback.

Regards,

Rod KM6SN