Control An Autotuner With Arduino Code
The Autotuner is the kitset from the EB104.com website.
Any tuner of the LC type with 8 shunt capacitors and
8 series inductors plus facility to switch capacitors to
either end of inductors will do the job.
The relays should be 12V / 24V types.
The output of a Stockton or Breune style bridge are connected to the forward and reverse power inputs (A6, A7) of the Arduino for VSWR detection.
The 8 capacitor relays are driven from D2 ... D9 via a ULN2003 driver chip
The 8 inductor relays are driven from D12 ... D19 pins. (D14 ... D19 are mapped onto A0 ... A5) which are set up as digital outputs. Again the relays are interfaced via a ULN2003 driver chip.
D10 is connected to a pushbutton to initiate a tuning sequence. RF should be applied to the tuner then the button pressed. A course tune sequence is initiated where the capacitors are stepped first looking for best SWR and holding on best capacitor. The inductors are similarly stepped and held on the inductor prodicing the lowest SWR.
D11 is an output to change the capacitor relay set from end to end of the series inductors.
A fine tune sequence is established to set exact capacitor value followed by best inductor. A reiteration is done to get the final values and the tuner waits for another button press.
Bit out of date now. Will sort out readme soon.