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:

How to connect HC-SR04 to any flight controller (INAV, Betaflight, Pixhawk too)

I’ve been asked to cover this topic multiple times. So, welcome to part one: how to connect HC-SR04 sonar rangefinder to INAV and any flight controller? The answer is simple: don’t. HC-SR04 sonar is absolutely not suited to work on a drone! It picks noise instead of ground echo and above a certain altitude (low altitude by the way) reports rubbish! From time to time it kind of work over concrete but immediately loose measurement capabilities over grass.

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.

How to use INAV Autotrim function – since you should do it

This is one of the most useful INAV functions for fixed wings! Servo autotrim solves the problem of trimming the airplane for level flight. Yes, flight controller does is “automatically” in stabilized flight modes, but for good Manual flight performance, you just have to have trimmed control surfaces. A long time ago you had to use some tricks and “adjustments” but for quite some time, INAV can do trimming for you.

Fear not, INAV 2.0 is here

We have finally done it! The first release candidate for INAV 2.0 is open for download. You can get it together with INAV Configurator 2.0 from GitHub.

What changed? The list is very very long and to be honest it is probably the biggest INAV release ever. There are over 200 tickets connected with INAV 2.0 release. The full list is just too long to publish over here. The shortcut of most important things is for you in a form of a video:

INAV Braking Mode for multirotors

Flying with a multirotor drone with INAV always had a problem: braking. When you were flying fast and then release the stick, a drone was not braking very fast, then it was going back to the place where you released the sticks. Rubberbanding. Irritating.

Over the time there were at least 2 attempts to fix it. Mine is at least the 3rd one and is called "Braking Mode". How it works:

  • when you release the sticks and speed is high enough, the drone is allowed to boost braking angle and speed
  • when braking is done, speed is low or close to zero, the current position is stored and new target position. Rubberbanding is gone

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

qUark Vision F4: flight controllers designed for INAV

Things are changing in INAV world. Different manufacturers start to realize that world does not end on racing miniquads and people might be interested in other types of flight controllers. Flight controllers that were not designed with racing in mind. And today I can finally show you prototype of such flight controller: qUark F4 Vision

qUark F4 Vision Flight Controller for INAV

qUark F4 Vision Flight Controller for INAV

What is so special about qUark F4 Vision. To be honest, not that much. Setup looks pretty standard:

  • STM32F4 CPU
  • MPU6000 IMU (gyroscope and accelerometer)
  • built-in OSD
  • built-in barometer
  • 8 PWM outputs
  • S.Bus inverter
  • Buzzer port
  • pins for WS2812b RGB LEDs

qUark F4 Vision Flight Controller for INAV

Until now, nothing fancy, right? Good stuff begins when we take a look at details:

  • PMW outputs power rail is separated from the onboard 5V line. That means you can use high voltage servos, as well as do not worry about frying onboard 5V voltage regulator
  • There is no onboard 5V voltage stabilizer. 5V has to provided from external source of your choice
  • It is not 36x36mm with 30.5mm hole spacing. It's still 30.5mm hole spacing, but one side is longer to fit all PWM outputs
  • Bottom side of PCB is flat. There are no electronic components over there. And that means FC can be attached with double-sided adhesive tape. Great for foamies
  • There are 3 fully operational UARTs (1,2 with S.Bus inverter and 4), separate I2C port (not shared with any UART like on all Revo derivatives) and possibility to use Software Serial
  • Special work in progress UIB port that is specific to INAV. It does not do much now, but it might change in the future
  • dedicated pads for HC-SR04/US-100 sonar rangefinder (I have not seen that for a while)

Something different, right? I'm putting mine on my experimental flying wing where it will feel like at home.

qUark F4 Vision Flight Controller for INAV

Like I wrote at the beginning, this is a prototype. It can not be bought yet. But if you are interested, you might email Malcolm at [email protected]

Troubleshooting INAV: why INAV is not arming

Few weeks ago I've decided to shoot more tutorial videos about INAV and this is the first effect of that decission: INAV Troubleshooting: why INAV is not arming