INAV Airmode and Motor Stop on Multirotors and Fixed Wings

What are Motor Stop and Airmode features in INAV and how they differ from each other when used on multirotors and fixed-wing airplnes? Should you use Motor Stop on multirotor? Should you use Airmode on a fixed wing? Long story short:

  • On multirotors, Motor Stop not recommended to use while Airmode is recommended to use. More than that, you can not use them both at the same time, since they exclude each other!
  • On fixed wing aircrafts Motor Stop and Airmode are highly advised to use together.

Matek F722-STD not booting without battery and how to fix it

What to do when Matek F722-STD flight controller is not booting without connected battery and connection from Configurator is not working? Simple, power GPS and magnetometer from a different pad.

All 5V pads are powered only when external power is supplied to the flight controller. Not when power is applied via USB cable. If you connected GPS and magnetometer to 5V pad, it will not work and screw I2C bus up. To solve this problem, connect GPS to 4V5 pad instead!

How to flash FrSky R9 Mini, R9 Slim and others with your radio

FrSky is not making things simple with R9 long range system. New firmware appears quite often and there is no way to flash receivers over the air. You can use some PC software, passthrough from FC and things like that, but from my perspective, as long as you can get to the receiver itself, the simplest way to flash R9 Slim and R9 Mini is to actually connect them to Taranis or Horus and do it from the radio itself. How? Like this!

Fix an old powerbank with 18650 Li-Ion batteries

Let's get our hand dirty and fix an old power bank. I got this thing a few years ago but recently it died. Li-Ion 18650 cells inside just died and now it even can not do a full charge of a smartphone.
What we will do over here:

  • get this thing apart
  • solder together 3 18650 batteries I got for cheap from disassembled power tools battery packs
  • I will be coughing after inhaling too much of soldering acid fumes
  • have a nice talk about a zombie apocalypse, nuclear holocaust, communism and Kapton tape
  • get things done!

How to use INAV Autotune

Autotune (or Auto Tune) that is present in INAV for quite a long time is a working solution for tuning PID (or rather PIFF) controller used by INAV on fixed wings (all airplanes, flying wings). Not like all the attempts designed for multirotors, this one actually works.

INAV Autotune can be used on any airplane and is fairly simple to use as long as you follow a few simple steps:

Soldering, rosin, flux and a Stannol x32-10i flux pen

If you really really want, you can solder without flux. But it is a painful experience. Almost all modern solders have flux integrated into its core. And as long as you do not try to solder anything big, it's enough. Of course, sometimes it is not enough and you have to help yourself with additional flux.

My favorite solution lately is a flux pen. Like Stannol x32-10i

INAV Configurator starts minimized and how to fix it

This is one of the most frequently reported things about every new version of INAV Configurator: from time to time, it starts minimized and it can not be made visible. It is a bugger connected with a fact that INAV Configurator does not have an installer. It's just "download and run" and after releasing a new version, we can not delete stored data during install. Since there is no install process.

Troubleshoothing INAV: magnetometer/compass is not working

Your magnetometer/compass is not working with INAV? Is the sensor red in Configurator? You are not the only one… Not only most popular compass HMC5883l is discontinued and what you get are Chinese clones, chip labeled 5883 might not be HMC5883l but something completely different. And I2C bus is very very picky and likes to give up on you….

This is how you might fix your problems: add pullup resistors for I2C SCL and SDA lines and/or lower i2c_speed