MultiWii Flight Controllers are capable of many flight modes such as Acrobatic, Auto-level, Altitude Hold and Head Free. By default only Acrobatic mode is activated so unless you are an advanced flyer you will want to start off with a flight mode that is easier to fly such as Auto-level mode with Heading Hold activated. The goal in this tutorial is to assign different flight modes to switches on your transmitter.
Most transmitters have many extra switches for such things as Landing Gear, Flaps and F.Mode. What we need is to get one or more of the switches on the transmitter to affect the state of one or more of the receiver (RX) output channels, such as AUX1 and AUX2. Transmitter's don't usually use the term AUX1/2 but simply have channels 5-9 dedicated to these functions. However, transmitters don't usually come already configured with the switches affecting these extra receiver channels. It's like the switches are there, and the receiver channels are there, but no connection between the switches and the channels exist. Go figure.
Since each transmitter is different the configuration of switches to Rx channels is beyond the scope of this tutorial. You will need to do some Googling (or Bing, or Yahoo) to find the appropriate tutorial for your transmitter. In all honestly, this process can be the most difficult. Hopefully you don't have the Turnigy 9X radio (like me) which makes AUX configuration worse than rocket science. If you do, I highly recommend the ER9X upgrade using the Smarty Pants board which has made my life so much easier!
When my 3-way toggle (F.MODE) switch is in the top position, then the AUX1 channel in MultiWii GUI shows LOW (1000us), see the Receiver Channels box in the diagram below. I want this to enable Auto-Level (ANGLE mode). Thus in the Flight Mode Matrix below AUX1 has 1 white box in the first column (titled LOW) at the row labeled ANGLE. When my 3-way is in the middle position AUX1 shows MID (1500us). I want this to enable HORIZON mode so I have a white box in the AUX1 second column (MID) at the row labeled HORIZON. With my 3-way at the bottom, AUX1 shows HIGH. I want this to not enable any modes and thus be Acrobat mode. So I clear out any white boxes in the 3rd column (HIGH) of AUX1. Because I currently have my switch in the top/LOW position, ANGLE mode is activated and thus lit green.
I don't have another 3-way toggle switch for AUX2 so I got fancy and configured two normal switches into a channel mix. This can be complicated to setup on your transmitter since there are only 3 possible channel states (LOW/MID/HIGH), so one switch (A) affects the channel only if the other (B) is in the OFF position. If B is in the ON position then A affects nothing. This is ok because one switch I can assign a feature like Heading Hold (MAG) and the other Altitude Hold (BARO). If altitude hold is active I want the MAG & ANGLE modes to be enabled anyway so the fact it overrides the MAG switch is of no consequence.
So in my case above, if switch B (BARO) is in the OFF position then switch A (MAG) becomes LOW or MID on channel AUX2. So in the AUX2-LOW column I want nothing (no MAG and no BARO) and in AUX2-MID column I want MAG to be active. Finally, when switch B is ON then AUX2 is forced HIGH no matter what the state of switch A. In this case, I want ANGLE, MAG and BARO to be forced active. You may notice I already have ANGLE activated using the 3-way toggle (AUX1-LOW) but if altitude hold is activated I want to ensure auto-level is activated no matter what the state of the 3-way toggle.