INAV Configurator 1.6: Presets

Upcoming INAV 1.6, and INAV Configurator 1.6 will bring many important changes. I will try to cover most of them in a next few days, beginning with Presets.

Because INAV can run very wide spectrum of aircrafts, it suffers a penalty of very general default values. Different frame sizes, propellers, multirotors, airplanes, flying wings. It is impossible to have one set of default values that will make all those different UAVs fly good right after flashing. And it’s not only about PIDs. Also rates, filters and other settings differs between them. Good default tune for 5″ racer will not work on 1.2m flying wing or 1.6kg quadcopter on 12″ propellers.

To solve this problem, INAV Configurator 1.6 introduces new tab: Presets.

Continue reading “INAV Configurator 1.6: Presets” »

Read More

3D Printed 433MHz Moxon Antenna With Arm And Snap Mount

It’s still middle of winter here in northern hemisphere, but I’m slowly preparing for next flying season. One of my goals is to push my DIY HC-12 Telelemetry System to a next level. In both range and quality. For quality I’m planning small hardware LTM decoder with LCD. For range, I want to reach at least 1.5km with 9600bps FU3 mode and 2.5km with 1200bps FU4 mode.

Continue reading “3D Printed 433MHz Moxon Antenna With Arm And Snap Mount” »

Read More

JavaScript PID controller

I suppose this is the first time programing topic came up on this blog. Probably not the last time, since this is what I do most of the time.

While working on serial port usage balancing for INAV Configurator I’ve quite accidentally created a PID controller in JavaScript. Maybe it’s not the most advanced PID controller ever, but has all the things required:

  • computes P-term
  • computes I-term
  • computes D-term
  • has output limiting
  • has I-term accumulator limiting

Continue reading “JavaScript PID controller” »

Read More

Cleanflight, what is up with you?

Those are my personal thought on the topic. If you do not aggree, it is fine, I will not argue or discuss. You have a right you your oppinion, I have a right to mine…

When I entered multirotor hobby about 2 years ago, Cleanflight was The Flight Controller software to get. OpenPilot was about to die, just like BaseFlight. Or maybe even BaseFlight was already dead… never mind.

Bottom line was that Cleanflight was it: fast realease cycle, great support, great community. Everything was just better there.

Then, somewhere in second half of 2015 it started to change. You do not remember what happened in the second part of 2015? It is more less the time when both Betaflight and INAV (both are forks of Cleanflight just like Cleanflight was the fork of BaseFlight) started to appear. I remember narration behind both of those projects: we will rewrite some code, make it fly better with racers (Betaflight) and handle GPS better (INAV) and when this is done, it will be merged back to Cleanflight. Continue reading “Cleanflight, what is up with you?” »

Read More

Programming ESP8266 with Arduino IDE

One of the best things about ESP8266 ESP-01 WiFi modules is that they can be programmed
using popular and well known Arduino IDE and act as stand alone board with WiFi
capabilities. Thanks to ESP8266 group process of integrating ESP8266 and Arduino IDE
is pretty simple.

First step is to add http://arduino.esp8266.com/stable/package_esp8266com_index.json to Additional Boards Manager URLs in Configuration in Arduino IDE.

Continue reading “Programming ESP8266 with Arduino IDE” »

Read More

Using PCA9685 with INAV

One of the hardware limitations of flight controllers that usually multirotor users ignores is a number of PWM outputs. To fly a quadcopter you need “only” 4 PWM outputs. Since most FCs have 6 outputs and 90% of multirotors are quadcopters, there is no problem.

In case of airplanes, this is not that simple. 6 PWM outputs is an absolute minimum to fly a classic airplane using MultiWii and derivatives (Baseflight, Cleanflight, INAV): 2 outputs reserved for motors, 2 ailerons, elevator, rudded. Suddenly, 6 outputs barely meets the requirements. If you want flaps, gas engine, pan & tilt or anything else, you are missing some outputs.

For some time INAV tries to address this issue by supporting external PWM driver: PCA9685.

Continue reading “Using PCA9685 with INAV” »

Read More

SmartPort inverter for F4 flight controllers

While STM32F4 family processors installed in newest flight controllers are superior to STM32F3 (and F1 of course) in terms of raw speed, they are inferior to F3 family in terms of IO handling capabilities. For example, F4 family is not equipped with UART port inverters. And that creates a series of problems when it comes to connecting various serial RX receivers and telemetry systems.

The most popular FrSky (Futaba) S.Bus serial RX protocol and FrSky SmartPort telemetry require inverted UART signal. If there is no hardware inverter on hardware UART port, they will not work. While S.Bus requires only one data line, external inverter is not a big issue. Some time ago I’ve published The Simplest Harware Inverter. One MOSFET transistor, one resistor and that’s all.

In case of SmartPort, it’s slightly more complicated. Not only signal is inverted, SmartPort also combines TX and RX UART line into single wire. That means the following:

  1. More complicated inverter is required
  2. Software has to support this case and fallback to unidirectional UART mode

Hardware

Continue reading “SmartPort inverter for F4 flight controllers” »

Read More

INAV: Launch mode video tutorial

One of the best new features of INAV 1.4 was Launch assistant mode (NAV LAUNCH). It greatly simplified the process of hand launching a fixed wing. All you had to do was to throw it into the air. INAV detected the throw, engaged motor(s) and stabilized flight and kept constant climb rate in the initial flight phase. INAV 1.5 will make it even better: it will also allow swing launch!

Since INAV 1.5 should be release in next 2 days, and there is very little info on INAV Launch mode, I’ve decided to create a short video showing how to do it.

Read More

INAV: how to setup asynchronous gyro

Together with version 1.4, INAV introduced asynchronous gyroscope processing. What is async gyro and why it is useful to have it, you can read here. In short worlds: data from gyroscope is read and filtered faster than PID controller updates motor and servo output.

When it is worth to enable asynchronous processing

In general, async gyro can be enabled when:

  • Flight controller does not ave enough processing power to run control loop faster than 2000us (500Hz mode). This is the case for all SMT32F1 boards like Naze32, Flip32 or CC3D
  • Flight controller is powerful enough to process PID control loop faster than ESC protocol (PWM, Oneshot125, Multishot) transfer commands to ESC and servos. This is usually true in case of all STM32F4 boards
  • INAV is setup on a “racer” machine that requires the best gyro signal possible

Async gyro should not be enabled when gyro and control loop frequency are the same. For example, 1kHz gyro and 1kHz control loop would give worse results than 1kHz synchronous processing. Continue reading “INAV: how to setup asynchronous gyro” »

Read More