Adding GPS to Flip32+ and Cleanflight

Flip32 and Flip32+ (10 DOF version of Flip32 with built-in barometer and magnetometer) are nice little flight controllers. And cheap. Some call them clones of Naze32, but this is not completely true. Yes, they are very similar, share the same hardware, but they are not identical. I would say they are better than Naze32 since have more features and are easier to extend. But that is not the topic.

One of coolest features of every drone is GPS support. This allows for both Position Hold and even navigation support. I will not explain how to configure Position Hold and navigation on Flip32+ and Cleanfligh today. The reason is simple: I’m still trying to fully understand PID controllers used in those modes: Pos, PosR and NavR. And it is not going very well I must say. Position Hold in low wind is OK, but navigation and PH in wind conditions is unreliable and I’m still unable to configure it to work well. But GPS even without Position Hold has some use. For example, Home marker on OSD when flying FPV.

 

Ublox Neo-6M GPS moduleIn this tutorial I will use Ublox Neo-6M GPS module, Flip32+ 10DOF and Cleanflight 1.9.0.

Continue reading Adding GPS to Flip32+ and Cleanflight

Let’s build class 250 quadcopter: frame

Many say that small 250 class quadcopter are super fun. Small, fast, agile, tough and crash resistant. I’ve decided to check it out and build 250 quadcopter drone by myself. And next few posts will be tightly connected with this topic. Let’s call it a build log.

The most important part of every multirotor is a frame. It decides about everything. For my quad I’ve decided to use ZMR250 clone frame made from carbon fiber.

ZMR250 quadcopter frameThere is also glass-fiber version of this frame, and it’s half a price (below $20 while carbon is around $35). So, what do we get for additional $15? We get 2 good things, and one bad. But let’s begin with good things:

  1. carbon fiber is lighter than glass fiber. My frame weights 145g while glass-fiber equivalent weights 181g. 36g might not seem much, but it is a difference after all. In my oppinion a difference worth $15,
  2. carbon fiber is more durable than glass fiber. At least in theory. So, in theory carbon fiber quadcopter frame should be harder to break during crashes. We will see.

An the bad thing? Well, carbon conducts electricity and can block radio waves. This means, that you have to be extra careful with all the cables and antenna placement. Insulate everything, never leave any cables touching the frame and antennas has to be placed as far from frame as possible. Some kind of mast would be recommended.

 

I have build a Depron plane…

How hard it is to build a RC plane without plans and starter kits? To do it in “Trust me, I’m an engineer” style. In mid June I’ve decided to give it a try and right now I can tell: it’s hard, but not that hard as one might imagine. All the problems I’ve faced were faced previously by someone else. I only had to ask right questions, read a lot, and use engineering sens to make plane work.

And well, it works. Way better than I expected it might work. Look for yourself.

Depron RC Plane

It even flies. See the maiden flight video.

Continue reading I have build a Depron plane…

Adding Bluetooth telemetry to Flip32+ and Cleanflight

When few weeks I wrote how to solve a problem of broken USB port in Flip32+ flight controller, I suggested that one of the solutions is adding a serial Bluetooth module to provide wireless connection with a bord. And telemetry. Excellent news is: this is pretty simple and cheap.

HC-06 Bluetooth Flip32

What we will need:

Flips: rule number one

Rule number one when doing flips with multirotor (quadcopter) drone is to watch your altitude. Specially with bigger machines without big thrust to weight ratio. If you will not control altitude, it might end like that:

Quadcopter (built on Raptile 500 frame and Flip32+ FC) survived without a scratch. Camera (RunCam HD) survived as well. It “only” detached for quadcopter and traveled few meters by itself until landed in grass.

Simple servo tester with Arduino

Servo tester is a useful little device that is needed specially when you do not have one. I’ve been placed in a situation like that few days ago what I was trying to connect ailerons with servos on my Depron plane and setup correct control throw. Luckily, I own a few Arduinos,  so 15 minutes later I owned a divice like that:

Servo tester with Arduino

It is an extremely simple servo tester based on Arduino Pro Micoro that can send 3 different PWM pulse lengths: 1000us, 1500us and 2000us. That gives min, neutral and max stick position on RC radios. Perfect to setup control throws and neutral positions.

Required parts:

  • Arduino. Any Arduino will do. I used Arduino Pro Micro, but any can be used. Even barebone ATmega328 running internal oscillator on 8MHz,
  • Breadboard,
  • Tact switch,
  • Some golpins to make servo connector,
  • Cables.

Electrical diagram goes as follows:

Arduino servo tester diagram

Program is also not complicated:

And at the end, it works like that:

Source code is available on GitHub.

Flip32 with broken USB port

Low price equals low quality. At least usually. I became clear to me (again) when I’ve broken USB port on my Flip32+ multirotor flight controller. I’ve pulled USB cable and USB socket stayed on a plug. Cheap solder. Or too quick soldering. No idea. Bottom line: unable to connect to flight controller board using USB cable. To make things worse, quadcopter was not tuned yet. It was flying, but not in the way I wanted it to.

What are the options in this case? Well, there are 3:

  1. get new flight controller board. Quite expensive since the only thing that is broken is USB port itself. Everything else works just fine,
  2. resolder USB socket. Might be the best solution, but since it’s surface mounted micro USB, it’s way above my soldering skills. THT? Why no prob. Simple SMD like resistor? Why not. More advanced? No…,
  3. use different way to communicate with flight controller.

I’ve chosen the third way. Flip32 (and Naze32) has build in hardware UART ports (as well as SoftwareSerial) that can be used to establish connection with a PC. Software like Cleanflight already allows you to use any serial port to talk to flight controller. Continue reading Flip32 with broken USB port

Flash BLHeli to Afro ESC

SimonK is most widely recognized ESC firmware in multicopter world. But there is a second option, in many ways much better than SimonK firmware. It is called BLHeli. It supports many different ESC, including both Atmel and SiLabs based. Plus, it has a cool software that allows you to configure you ESC without programming card. Just connect your ESC via serial-to-USB interface and you are ready to go.

AfroESC were supposed to be state of the art controllers, SimonK out of the box, easy to flash thank to special USB interface/programmer. And ready to accept different software, BLHeli included. There is only one huge “but”. You can buy them, you can buy Afro USB Linker (Turnigy USB Linker is exactly the same), but nobody will tell you how to do it. Number of articles is very limited, and the only useful I’ve found is this one. So, here we go, now there will be a second one!

How to flash BLHeli to AfroESC

What you will need:

  • AfroESC (obvious)
  • Afro USB Linker / Programmer
  • Windows machine with drivers (keep reading)
  • BLHeliSuite
  • LiPo battery, the same you use on your drone

Continue reading Flash BLHeli to Afro ESC

x525 V3 Quadcopter Frame Review

There are many cheap quadcopter frames on market. Big, small, X, H, foldable, good and bad. And choosing a correct frame for a purpose is both hard and critical for further drone performance. One of cheap, and on a first glance, versatile frames, is x525 V3. Is it worth the money?

x525 V3 quadcopter frame review

Well, it’s a hard question. Before I will go to any conclussions, short description of x525 frame.

  • Material: glass fiber and aluminium
  • Type: X or +, you can choose, it is symmetrical
  • Weight: around 385g,
  • Size: 525mm
  • Integrated landing gear with sping amortization
  • Foldable
  • Power distribution board

Landing gear is quite clever and should absorb most of impact force in case of hard landing. In theory it is correct, but my experience says that it does not matter. It maybe works in case of normal, controlled landing. But in case of really hard landing, read as crash, it does not matter at all. It is a useless feature that only breaks, adds extra weight and really does very little. After breaking 3 sets of front landing skids, I just replaced them with some steel wire. Does the same, and weights less. Like I said, useless feature. Continue reading x525 V3 Quadcopter Frame Review

Dead Rat, wooden quadcopter, maiden flight

Last week I was, finally, able to perform a maiden flight of my DIY wooden quadcopter (here and here). I will not say it was huge success, but it was a success alright. What went like expected? Well, quite alot. First of all, it flies and has enough thrust to weight ratio to do flips and rolls. And is pretty stable in hover. What went not like expected? It is highly unstable on yaw. Really, really unstable. Probably rear propellers are too close to each other and I have to work on PID settings. As soon as I will have enough spare time…

In a mean time, here is a short video from DeadRat’s maiden flight:

Final configuration goes as follows:

  • Motor to motor diagonal: 500mm,
  • Motor to motor front arms: 370mm,
  • Motor to motor rear arms: 300mm,
  • Materials: 3mm plywood and 15mm wood spars
  • Motors: Suppo A2212/13 1000KV
  • ESC: XT-Xinte 30A
  • Flight Controller: OpenPilot CC3D (clone)
  • Battery: Turnigy 5000mAh 3S 25C
  • Propellers: Gemfan 1045
  • Start weight: 1212g
  • Hover time: 21 minutes

Next steps: tune it up and move battery to top. Somehow I do not want to construct a landing gear for it…