I have a Turnigy 9x transmitter and I needed a 6-position switch for the flight MODE. The radio had only a 3-position switch and I didn't want to deal with how to program transmitter to combine two switches. The transmitter did, however have a potentiometer labeled "AUX_2" connected to channel 5. So I made my own 6 position switch with a rotary switch. It works great.
If you want to duplicate my setup-
GRAYHILL rotary switch (P/N 50DP45-01-AJN)
Knob of your choice for above.
4 X 1K 1% resistors
1 X 1.1K 1% resistor.
All of the above are available from Digi-Key. If you want to use a different (or cheaper) switch, make certain that you get one that is rated for LOGIC LEVEL (not power) use. Switches that are designed to switch power have different contact materials, and will often fail when used to switch the microamp currents used in this circuit. The GRAYHILL switch is around $12, but worth it. It fits perfectly in the space formerly occupied by the potentiometer.
Open the case and remove the connector that attaches the harness from the back case to the circuit board.
Unsolder the brown, black and red wires from the potentiometer.
Pry off the knob on the potentiometer and remove the nut that holds it into place. Remove the potentiometer.
Follow the directions that come with the rotary switch to reduce the maximum number of positions from 8 to 6.
Solder the 1.1K resistor between positions #1 and #2 on the switch. Make certain that the wires do not
touch the metal body of the switch. The resistor bodies can stick straight "back" behind the switch if you cut one lead very short and attach it to the switch pin and fold the other lead along the resistor body to the next switch pin.
Solder the other resistors (all are 1K) between positions #2 and #3, #3 and #4, #4 and #5 and #5 and #6.
Now connect the RED wire to switch position #1, the BROWN wire to the center pin of the switch, and the BLACK wire to switch position #6
Open up MISSION PLANNER and set your modes!