Justa copter 1

Desire

For a while now, i've been meaning to get into the quad-copter hype that's been raging through the hacker/maker/RC-communities. So far, the prohibitive prices and/or domain-complexities have kept me out. While I do love tinkering with electronics/tech/materials, I feared that the amount of time/work that I'd have to stick into making a quad-copter would be so large that it'd end up in a box as a half-finished project, never having flown.

The alternative would've been to buy a 'as-ready-as-possible' system and get that into the air with a minimum of fuss; but it seemed that the only solutions to achieve that involved paying a lot of money for fully integrated flight-controllers; anything from 100 euro and more for some of these.

The AUV-NG, Mikrokopter, Ardupilot, OpenPilot, etc, projects all seemed to come up with figures around 700euro for a flying and ready system after all the components and putting it all together.

Flight Controllers

Recently, however, I decided to bite the bullet and look around to see what's available out there. The offerings available were actually quite surprising!

It seems that, outside of the well-known and 'pro-grade' projects out there, the 'DIY'-guys have been plodding along quite a bit as well and have had some luck getting their projects on the radar of a number of chinese manufacterers which ended up creating boards that are compatible with their firmwares. Most of these center around arduino-compatible systems; the MultiWii, MegaPirate and even some ArduPilot stuff.

In essence, most of the 'pro' boards are designed from the ground up to run on some fast processor, include 'the bestest' sensors and basically take a no-compromise attitude to the engineering-challenge. The arduino-based designs, however, seem more pragmatic in scope and have ended up including a lot of the more useful and worthwhile features of the 'pro' designs out there, over time.

In the 'simple' camp are a number of flight-boards that are based on simple analog comprators and a little bit of Atmega-logic to keep a quad or quadx in the air. On the other end of this spectrum are boards of up to 70 dollars (Crius V2.0 on ebay... cheaper elsewhere) that include an atmega2560 , ftdi, barometer, magnetometer and the usual accel/gyro combo's.

The boards are made to be arduino-alike. They either require an 'ftdi-cable', an 'isp-programmer' or even come with an FTDI onboard. A lot of them can be programmed from within the arduino programming environment for this reason.

I'm still digging through the several code-repositories out there, but at least MultiWii and MegaPirate seem to be much of the same thing; projects spun off from code that turned an arduino + a Wii+ into a quad-copter controller. The Wii+ is a little WiiMote add-on that allows for greature accuracy and stability for gaming due to better MEMS-gyro/accelerometers; connected via the i2c bus that the WiiMote uses.

From there, people made boards with different gyros/sensors/etc and some of these designs were generalized to such an extent that chinese designs started to pop up that worked for different firmwares and a great number of different multi-rotor configurations, among which anything from 3 to 8 rotors AND two servo's (for camera-rig). Tri-copters use a servo to angle thrust on one of the rotors.. Some of the firmwares are even geared towards adding stability to winged models, instead.

There's also an interesting 'odd-ball' called the 'KK' or 'KaptainKuk' board. Korean in origin, the original KK-board wasnt very advanced and has been plagiarized/copied innumerous times. The KK2.0 , by contrast, is a very convenient device , offered in cooperation with Hobbyking.com exclusively, and provides for an onboard LCD and buttons to configure all it's operational parameters 'on site'. Sadly, no support for telemetry/gps/etc or any interaction with third-party gear is the result.