This is version 2 of my demo for an arduino antenna tuner. In this version I swapped the coil with a new, somewhat larger one, which has an extra connection about halfway. Using a relay (controlled by the Arduino) the inductance can be switched between half and full. In each position, the capacitor makes a full sweep, while the Arduino monitors the reflection (watch the right meter in the back!). After this, it puts the inductor and capacitor in the position with the lowest SWR. This demo is quite slow, I experimented with different speeds and was able to let it tune within 2 seconds! Details, pictures, schema and code: ernest.utreg.net
I am from China, HAM BH7PVE, by e-mail with a PA3HCM want his help, PA3HCM soon provide the experimental procedure to me, he is very friendly and warm. For which I am very grateful.
After my test program is very good, very accurate tuning, use ardiuno to control the antenna is a great invention, want to promote