• Cleanflight is dead...

    Only 5 weeks ago I've written that Cleanflight has a problem. Looks like, the problem was much bigger than I expected. Today in the morning, Dominic Clifton aka. Hydra essentially killed the project by resetting GitHub repository to Betaflight 3.1.

    It was announced on Facebook:

    Cleanflight v2.0.0-RC1 is out now, with all the new features from Betaflight v3.1 - please share this post!

    Thanks to the hard-working betaflight developers especially Boris B, Jason Blackman and Martin Budden who have been doing fantastic work for us all!

    Also, all GitHub Issues and Pull Requests were deleted.

    What does that means? More less the following:

    1. Cleanflight lost all it's uniqueness and is Betaflight under different name
    2. Pilots that were using Cleanflight on airplanes or big multirotors are left alone. Betaflight aims on mini-quads, not airplanes!
    3. Why anyone would want to use CF when BF is there and this moment it offers better community support?

    The way I see it, it was a nice ride, but now it is over and Cleanflight is dead. Too bad, since it had a huge impact on multirotor community over last few year...

    Read more...
  • Fixed Wing 101 - Lift, Angle Of Attack and Stall

    With this short article I would like to initiate new series: Fixed Wing 101 where I will describe some basic concepts connected with fixed wing airplanes that should help beginners to enter the hobby. Today: why airplanes fly and why, from time to time, they fall down from the sky...

    Lift

    Airplanes fly thanks to the lift. It is a force generated by wings (by the way, propeller thrust and wing lift are the same force. After all, propeller is a rotating wing) thanks to pressure difference. When air pressure below the wing is higher than above it, lift appears. To archive level flight, lift has to be big enough to counteract mass and gravity.

    The most important condition for a wing to generate lift is: wing has to move though the air (or air has to move around the wing). If there is no movement, there is no lift.

    When there is air movement, there are two factors responsible for lift:

    Bernoulli's principle

    Bernoulli's principle states:

    when gas or liquid is moving faster, it has lower pressure.

    Simple. To obtain lower pressure above the wing, we have to make air move faster over there. This is why wing has a shape (airfoil) it has: top side (above chord) of a wing is longer than the lower side. Wing splits air into 2 stream. Upper one has longer way to travel than lower one, so it has to move faster. If it moves faster, it has lower pressure. If it has lower pressure, lift appears.

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  • Review: BuildTak Printing Surface

    For last few months I've been happily 3D printing PLA on glass. Prints were repeatable, initial adhesion was just fine, ready print was easy to remove after glass cooled down. But I wouldn't be me if I did not wanted to try something new. So I tried "the ideal 3D printing surface" BuiltTak.

    My initial impressions were very positive. Nice mate surface a little similar to fine grain sanding paper. I was a little afraid that adhesion will be even too good and it will be hard to remove the print. But hey, they had to think of it, right? After all, BuildTak is quite expensive after all. Read more...

  • How to print with elastic filament

    Elastic filaments opened brand new areas for 3D printing. We are finally able to print something that bends, compresses and stretches. While TPE (ThermoPlastic Elastomer) filaments like NinjaFlex or FlexiSmart are still about 4 times more expensive than plain old PLA, they are not so expensive not to give them a try.

    Unfortunately, due to the fact that they are elastic even before melted and extruded, they require special printing conditions. During my experiments with FlexiSmart I've came down to following conclusions:

    1. Because TPE is elastic, flow through the nozzle has to be as smooth as possible. If not, it will coil inside extruder
    2. Bowden extruder system greatly increases chance of failure. Friction of bowden, while small enough for ABS or PLA, is too big for TPE. Filament will coil. Direct extruder gives less chance of failure
    3. One has to pay big attention to the distance between extruder nozzle and bed. Usually it has to be a litter bigger that for PLA or ABS. In all the cases when I was switching from PLA to TPE, I had to raise nozzle a little. If not, TPE coiled. TPE has better initial adhesion than PLA, so rising a nozzle does not have side effects
    4. Filament retraction is a huge NO NO. Disable retraction since it will increase the chance of coiling significantly
    5. With no retraction it is a good idea to enable Combing. Nozzle, instead of taking the shortest route to travel, dripping TPE everywhere, will move above already printed layer. This greatly improves print quality
    6. Top printing speed is 30mm/s, but I recommend slower speeds. I have best results when printing at 15mm/s. On 25mm/s quality is still acceptable, but degradation starts to be visible
    7. I had best results of TPE printing on glass with 220deg nozzle temperature and 60deg bed temperature
    8. Not everything can be printed with elastic filament. Any thin vertical structure will come deformed. After all, it will move during printing due to a friction with extruder nozzle

    While I was printing with FlexiSmart, almost all points from the above list will be true for other TPE (NinjaFlex). Temperatures might be slightly different, but general rules applies.

    Read more...
  • Mechanical Bat: Bat Bot B2

    Nature gave ability to fly to birds, insects and some mammals quite some time ago. We, as a species, learned how to fly only very recently. And let's be honest here. We are not very good at it. We need machines to fly. Any our machines are not very efficient at that task. They require huge amounts of energy to do it, need maintenance and make a lot of noise. Look at birds and bats. They fly for longer using less energy. And they do it with grace.

    This is project that caught my attention only today: mechanical bat from University of Illinois called Bat Bot B2.

    Bat Bot, from Caltech von PopSci

    Take a look at that video. Maybe it's not stable or capable of longer flights yet, but I'm really, really impressed. One day I would really like to have an UAV like that!

    Via Hackaday

    Read more...
  • ESP8266 and DS18B20 - wireless ThingSpeak sensor

    Here is another small project of mine: battery operated ESP8266 ESP-01 WiFi thermometer using DS18B20 and ThingSpeak API to collect data.

    Before we proceed, you should:

    esp8266 ds18b20 thingspeak sensor

    Read more...

  • Hardware SmartPort Inverter using BC547 bipolar transistors

    This post is only a short update for SmartPort inverter for F4 flight controllers. Here is alternative SmartPort inverter circuit using bipolar BC547 instead of unipolar 2N7000. All other aspects of operations are the same like in MOSFET version.

    FrSky SmartPort S.Port hardware inverter for F1/F4 flight controllers

    Read more...
  • ESP8266 ESP-01 Low Power Mode - run it for months

    Amazing ESP8266 ESP-01 WiFi boards have pretty irritating problem: theirs power consumption is pretty high. Minimal power consumption of about 70mA when doing nothing and above 100mA when when transferring data makes it rather impossible to use it on battery power for a longer period of time. Set of 2 AA batteries would be drained in less than a day. Not good.

    There is a way to make ESP-01 work for months using something called deep sleep mode. When in deep sleep, ESP8266 disables almost all of its functions and reboots after specified period of time. There is one catch: ESP-01 is capable to enter deep sleep, but unable to restart and resume operation. XPD_DCDC MCU pin in not connected to RESET pin. To fix it, you would have to solder thin wire between XPD_DCDC and RESET pin just like on a picture below:

    ESP8266 ESP-01 Deep Sleep hack

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  • INAV 1.6: Fixed Wing PIFF Controller

    Another new feature of upcoming INAV 1.6 (BTW, INAV 1.6 ALPHA-1 has just been released) is brand new PID controller for fixed wings. I repeat: this new controller is used only on fixed wings, multirotors are not affected.

    So, what is new about this new PID controller? First of all, it is no longer a PID (Proportional, Integral, Derivative). It is a PIFF (Proportional, Integral, Feed Forward) controller. What is the difference?

    Traditional PID controller computes error between setpoint and measurement and feeds it to 3 modules: P, I and D.

    PID controller

    Read more...

  • How to connect APM Power Meter to Cleanflight and INAV

    This topic was eluding me for some time now. It's time fix the problem and finally present a short tutorial how to connect 90A APM Power Meter for flight controller boards like Naza32, SP Racing F3 or any other running Cleanflight / Betaflight / INAV software and equipped with Current Meter ADC input.

    I will not show where to connect APM Power Meter to flight controller, since this differs from board to board. Some boards have dedicated pins, on some boards PWM input pins are used for Current Meter ADC. You have to refer FC documentation and / or flight controller software documentation.

    Read more...

Paweł Spychalski

I'm Paweł Spychalski and I do things. Mainly software development, FPV drones and amateur cinematography. Here are my YouTube channels: