The RCI-SE board includes 2 ADC IC’s:

IC2 for Azimuth
IC4 for Elevation

When a Voltage between 0V and 5V is applied on pin #2 on those IC’s,  around 17µsecs later it’s converted into a digital value. The ARSWIN reads the digital value, and calculate the antenna position. This process is done based on some parameters that the user must provide first:

1 Total rotation angle (normally 360 or 450)

2 Left/CCW Rotor position (180 or 0)

3 Left or CCW ADC value

4 Right or CW ADC Value

Aditionally the RCI-SE has 4 POT’s (2 peer input), that will be used for adjust the voltage limits at each input pin (pin #2). Those POT’s are:

  • POT1: Amplifier or Gain Pot. (Azimuth)
  • POT2: Amplifier or Gain Pot. (Elevation)
  • POT3: Zero Offset (Azimuth)
  • POT4: Zero Offset (Elevation)

POT1 and POT2 adapt the GAIN of each input, and will be ajusted when the rotator is at the CW or UP limits. POT3 and POT4 adapt the ADC value when the rotator is at the CCW or DWN limits.  
How must be done?
Check that POT3 and POT4 are at their CCW limits.
You must turn the rotor manually to the CW limit. This point should be 360º, or 180º. Some rotors as Yaesu, Kenpro or ProsSisTel allow a rotatation greater than 360º, however this overlapping is not useful for the ARS. So, remember to use this CW limit as 360º.
When this CW point is displayed at the rotor displayer (Control Unit), check the “Current A/D Value”. Adjust POT1 (Azimuth) or POT2 (Elevation) untill the Current A/D Value is as close as possible to the Max ADC Limit.

This limit will be 1023 for 10 bits ADC or 255 for 8 bits ADC. And PRESS the RIGHT Button when it’s done.

This limit will provide around 5V at point X2 (Azimuth) or X3 (Elevation)

Later, turn the rotor to the CCW or Left Limit. It will be 0º or 180º. The actual A/D Value will be a value close to Zero.

If this value is not near to 0, ajust POT3 (or POT4 for elevation) till you read that the A/D Value is 0 or some value close to 0.

And Press LEFT Button.

Now the ARSWIN has the 2 limits and will calculate the antenna position.

On above screens, the 2 limits selected are: 1021 and 9

RCI-SE Board with the 4 Pots


Remember that you must indicate the total rotation angle that use to be 360º or 450º in most cases. You can also limit the rotation to a lower value as 180º or 90º in those cases where the rotation is limited by some object.

Also you must indicate the left/CCW Limit of your motor. This parameter will indicate the position of the motor when it’s located at the left/CCW limit.

Some examples are:

        • Yaesu, Kenpro –> 0º
        • HAMIV, T2X —–> 180º


Offset must be set to Zero.