The next thing that we’ll be looking at while setting up iNav 3.0, is setting up the GPS. We should have done all the work for this by setting up the ports. This is really about some settings that can help out, and making sure that the GPS is working.
The first place to look is at the top of the page. There is a GPS status indicator. First remember to plug in the battery. Some flight controllers need this to provide power to the GPS. If this is blue, everything should be good. You can validate this on the GPS page. Check the Total Messages. If the number is increasing, the GPS is communicating with iNav correctly.
If it’s red, there is a communications problem. The first thing to check is that the UART is wired correctly: Rx to Tx and Tx to Rx. If that is good, then the problem could be with the port speed or GPS Protocol. So check with the GPS manufacturer for the correct protocol.
Optimising your settings
Once the GPS is working, there are a couple of settings that can potentially improve the GPS performance. The first, is if you use the UBLOX Protocol, you can try using UBLOX7. Another thing to set it to enable Galileo Satellites. If these satellites are not available, this will not have a negative effect on anything. But, if the satellites are visible, you will benefit.
One final improvement change is to the Ground Assistance Type. Unless you are travelling with the model all the time. It is beneficial to set this to your local area, as it will improve the altitude accuracy. The last, optional, settings are at the bottom. They are the settings for Timezone Offset and Automatic Daylight Savings Time. If you set these, the clock in iNav will be set correctly via GPS. Notice that the timezone offset it in minutes. So if you are in California, you will need to enter -480.
Failsafe and RTH
The failsafe settings
One of the most useful features is the RTH on failsafe. So it would be silly setting up iNav 3.0 and not covering this. What this will do is: if you lose control signal with the plane, it will fly back to you and loiter at home or “land”. There are a few different options which we can look at soon.
The first thing that you want to do is head to the Failsafe page. There’s only one thing we need to do here, and that it set the Failsafe Procedure to RTH. Then click that Save and Reboot button. Next, go to the Advanced Tuning page.
Testing the failsafe
Seeing as we are here, now is as good a time as any to test the failsafe. An essential part of setting up iNav 3.0 is making sure failsafe will work. Make sure that your transmitter is turned on and on the correct model, and that your receiver has power. At the top, centre of the screen the parachute icon should be grey. This shows that the Rx connection is working. Next, power off your transmitter. The parachute icon should now turn red, indicating Rx loss and entry in to failsafe mode. Switch your transmitter back on, and the parachute should once again be grey. If this has worked as described, all is good. However, if this is not the case. You will need to look at the failsafe setup on your receiver. For FrSky you should set the failsafe mode to Hold or No Pulses. With Crossfire, it should be set to Cut. Other systems will need setting up differently.
Configuring the RTH
As mentioned earlier, the RTH settings are set up on the Advanced Tuning page. This page has changes a fair amount in iNav 3.0. Once loaded, scroll down to the Generic Settings section. There you will find RTH Settings. At this point, I’m going to direct you to the iNav Wiki. I have separated out the Return To Home settings to a separate page. This covers how all the different RTH modes work, and now how the different Climb First settings work. So it would be well worth having a read of this before continuing. It will open in a new tab, so you will not lose where you are here.
Here are my basic RTH settings. I’m not recommending people copy these. You need to set the RTH settings need for your flying area. Most of this is covered in iNav Wiki document above. But, I’ll mention a few things here.
RTH altitude mode will be set based on the area you are flying in. AT_LEAST_LINEAR_DESCENT will work well in most standard situations. But if you’re flying around hills or mountains, MAX would be a better option.
RTH Home altitude is a useful setting, as if your RTH altitude mode has the potential to have your model quite high when it reaches home. This setting will loiter the model down to the altitude set here. I set mine so that it is above obstacles, such as trees, at my home location.
Climb before RTH is something that is very specific to your flying environment.
- Turning first (Climb before OFF) would be the most efficient RTH climb mode, as you are climbing on the way home. However, some times turning first could result in you ending up in a tree.
- If you like flying low, there is more chance of obstacles to the side of you, as you are more likely flying towards a gap or open space. This is why mine is set with climb first on. This does mean that it is a less efficient method, as there is 50% chance you could be flying away from you; so are using energy to climb while still heading away.
- The last option, and new to iNav 3.0, is a spiral climb first. This sees you loiter up to altitude. It is useful in hilly areas, where yo could potentially have terrain obstacles in any direction, so need to get up to altitude before returning.
The last thing that I’m going to mention is Land after RTH. iNav does have a “land” feature for fixed wing. Though in essence it is really a controlled crash. I used to have this set to NEVER. But, with the new Safehomes feature (2.6), I have set a safehome to be used with only failsafes. I have also set Land after RTH to FS_ONLY. Regardless, I would only use the land feature in an emergency, and on an area of open, flat ground.