PREFACE
Here's a bit of what I've gleaned from researching, and now, owning a Phantom 2 Vision (P2V). I'll introduce some acronyms as I go. If you do any reading on this technology you will likely encounter many of these .... without explanation. There's also some confusion in the use of the terms controller (two meanings) and transmitter. In the traditional remote control (RC) world the box you use to control your craft is called the transmitter as it transmits control signals to a receiver in the craft. In the Phantom world this term is seldom used, this box is referred to as the control or controller. Unfortunately the magic electronic box in the craft is also called the controller (a NAZA-M V2 device in the P2V's case), as it actually decodes the signals received from the transmitter and on-board sensors and operates (i.e., controls) the motors. So the controller (in your hand) sends a signal to the controller (in the craft) to operate it. I have no idea why they don't use the term transmitter. Moving on ...
DJI PHANTOMS
The DJI Phantom is a line of quadcopters (four props, rotors, rotoprellers - take your pick, something else to debate). Quad-, hex-, and octo- copters have been around for about ten years but up until recently were really only available to hobbyists who could round up the parts, assemble them, and had the skills to fly them. Recent advancements in electronics have made them relatively easy to fly. The original Phantom came only with a mount for a GoPro, no camera included. The P2V comes with a (detachable) camera whose operation is integrated with that of the aircraft. The Phantom 2 non-Vision (P2) does not come with a camera but does have a gimbal for a GoPro camera. As with any hobby, all manner of OEM and third party accessories are coming available. Folks who had the original Phantom and tried using it with the WiFi on their new GoPros ran into major problems because the original Phanton's control radio operated at 2.4 GHz, same as the GoPro.
PHANTOM 2 VISION
The Phantom 2 Vision was the first quad to come as a total, integrated package (others are following close behind). It's a ridiculously expensive toy (but that's why I worked all those years - to get toys). Its main claims to fame are that it's pretty easy to fly (on-board GPS, compass, gyro, etc.), one can see what the camera sees in real time on a smartphone, and it has a Return To Home (RTH) feature that's activated when it loses the control link.
PILOTING OVERVIEW
Regards piloting ... the craft is far easier to fly than the fixed wing planes and helicopters I've flown in the past, but it still requires developing some skill to put it where you want it. The main difference is that those older craft required one to be piloting ALL the time (especially challenging with any wind) but, with the Phantoms, once they're properly pre-flighted and off the ground, the pilot can let go of the controls and the craft will pretty much stay within a six foot radius of where it was left. It'll probably handle winds up to 15MPH (or more), but it is going to be bouncing around a bit at that speed, gusts being more of a problem than steady wind - it can't react until it senses movement. And there are additional control aids (such as Intelligent Orientation Control - IOC - more later) to help with piloting. The claimed range is 300 meters (Euro mode, the default) and 500 meters in the U.S. (switching to U.S. mode simply requires turning a potentiometer in the controller). Flight time for the P2V is about 25 minutes.
SMARTPHONES & FPV
The smartphone (and some tablets, maybe) viewing feature means that it's capable of First Person View (FPV) flying. Hobbyists have been adding various FPV schemes to their aircraft for some time. FPV flying is pretty risky because the pilot has very limited peripheral vision (and, when flying, up and down are as important as left and right). I seriously doubt I'll ever fly other than by Line Of Sight (LOS), i.e., where I can see the P2V. However the FPV works really well for lining up still shots and video. A caution is that the smartphone app only works with the newest phones. The P2V controller has a clip mount arrangement for holding a smartphone within easy view. Beyond seeing what the camera sees, the smartphone app allows the pilot to control the camera, e.g., start/stop video, take still shots, operate the gimbal up/down, adjust camera settings, etc. One's smartphone actually links to a repeater mounted on the controller, and the repeater links to the camera over 2.4 GHz WiFi. This gives an operating range beyond what a smartphone could achieve.
BASIC CONTROL & FAILSAFE
The craft is controlled from a typical RC type transmitter with two joysticks ... right stick controls forward - backward and left - right, left stick controls throttle (up - down) and yaw (left - right). The controller communicates with the craft via a 5.8 GHz signal. Assuming one has done the pre-flight correctly (waited for GPS lock and compass operation confirmation - indicated by specific craft light color/pattern), if the craft loses the link to the controller it will go into failsafe mode (RTH) and fly back to where it took off. If flying at less than 66 feet when this happens, it will ascend to 66 feet, fly DIRECTLY back to the take off location, and then land. If one has flown over or around trees, buildings, etc. taller than 66 feet, it's going to crash into them on the way "home". If it's flying at more than 66 feet, it will maintain altitude until it gets over the home position, and then land. Before descending it will pause for about 15 seconds so the pilot can attempt to regain control (by toggling a switch on the controller). The control signal is more or less line of sight though it extends far beyond where one could actually see the Phantom. And, of course, the signal does get through "open" objects (like winter trees) and bends (somewhat) around solid objects.
RADIO INTERFERENCE
Having mentioned the radio signals this is a good point for the warning that using the P2V in an area with lots of potential interference is risky. There are many devices that operate in the 5.8GHz (and 2.4 GHz for that matter) range. Heavy industrial areas, along power lines, next to a cell tower, TV transmitter, etc. are not good choices for flying sites. Of course it's very hard to prove such produced a problem and there really aren't any crashes or fly-aways that have been documented as being interference driven. But in the aftermath of an unexplained "incident", if such things are in the area, they are pointed at as prime suspects. The forums that deal in these craft generally say stay away from such if you can, but then provide all manner of anecdotal evidence which suggests it's not a big problem. This issue is worth mention as it may impact where you'd be willing to use this device, or at least make you aware of the potential for problems in such areas and watchful for any unexpected behavior.
FLY-AWAYS
Every new technology must have a boogey-man, and for the Phantoms it's "fly-aways". The classic fly-away is described as follows, "I did everything right, and was having a great flight. Then it started acting hinky and I couldn't get it to respond. I tried everything I could think of, and finally switched off the controller to activate RTH ... but it just flew off to who knows where". There is much discussion on the cause of fly-aways and there's a multitude who blame design faults. There are probably also as many folks who don't buy the design flaw theory and suspect pilot error of some kind, generally in the set up or pre-flight routine. DJI has tweaked the firmware to mitigate some types of interference issues, but the problem is there's been no real study of the failed craft (most are not recovered) so no one really KNOWS what the cause(s) may be. The best (only useful?) advice to date is to make sure you have loaded the latest firmware (controller and Phantom), follow the pre-flight routine religously, avoid flying in areas with potential electromagnetic interference, let the Phantom hover a few feet off the ground for several minutes at the beginning of each flight, and watch closely for the loss of GPS lock or any unexpected behavior (e.g., doing its own thing or not doing what it's told). In the case of any unexpected behavior, get 'er down now and start over.
DESIGN & DOCUMENTATION
DJI is a Chinese company (Nanshan District, Shenzhen, Guangdong, China). Unlike the "copy" companies China is famous for, the Phantom is their design, and it's really quite amazing. Of course, as with any high tech, new technology there have been problems ... or supposed problems. Every time something goes awry with a Phantom the immediate reaction is to blame the device. There is a massive amount of processing going on inside this little package, and none of it can be seen, so it gets the blame. There are few reports of problems due to mechanical issues (a loose connector, a bad motor bearing, etc.). Being of Chinese origin, the documentation is marginal at best, made worse in the case of the P2V because the P2V operates in a simplified mode (switchable) of DJI's NAZA controller, and the P2V documentation is not linked to the NAZA documentation. NAZA controllers are used in a lot of hobbyists' aircraft and it has some really awesome capabilities. So the bulk of what one can readily learn about the P2V comes from on-line forums. I'm involved in forums of various interests and for some reason the P2V forums seem to have more than their fair share of, err, um, challenging members. Still, there are a number of knowledgeable and helpful folks on the related boards. Phantompilots.com seems to be the most focused and active, others cover broader RC flying interests so the Phantoms are just a subset there.
DJI "DRAMA"
Related to the documentation issue, there is drama (why does there always have to be drama?). The CEO of DJI U.S., a guy named Colin Guinn, and DJI parted ways in January, 2014 (evidently not his choice). The bulk of DJI's official (english) Phantom operating instructions were videos on YouTube. When Colin went away, so did the videos. Now some of them seem to have reappeared. Hard to say whether they'll be there from day to day. Still, there are lots of videos made by Phantom owners that are on-line, some are just not as good (and maybe not as accurate). The latest development is that Colin has filed suit aganist DJI. Stay tuned. On the forums, DJI customer service is routinely bashed. Some say this was the reason for Colin's demise though there's no proof. In any event, DJI recently opened a U.S. customer service center in LA, so time will tell how that works out.
VISION MODE & SET UP
I mentioned NAZA and IOC earlier. The P2V comes set in Vision 2 mode. There are two 3 position toggle switches on the transmitter. In this mode only the right hand switch (S1) does anything. Toggling it on-off multiple times puts the Phantom in compass callibration mode which you need to do before your first flight in a given part of the world (aka, the compass dance - involves rotating the Phantom on two different axes). Some say do it at every flying location, others say you only need to redo it if you move the Phantom hundreds of miles. DJI is in the latter camp. Part of setting up the Phantom requires downloading two apps to a PC (Windows is covered, Apple support seems to be lagging somewhat). One of these apps is used to configure the Phantom, the other to configure the controller. Configuration is where one can switch from Vision 2 mode to NAZA mode.
NAZA MODE - S1 SWITCH
In NAZA mode the right hand switch (S1) allows you to select Vision 2 / GPS mode, Attitude mode, and initiate RTH or select Manual mode, the latter choice being made in configuration. Manual mode is generally reserved for those who have excellent skills or a (Phantom) death wish. Attitude mode essentially disconnects the GPS feature - the craft will roughly hold it's "attitude" based on compass and altimeter sensors, but it will drift with the wind. Initiating RTH means invoking the return home feature without having actually lost the control signal ... basically the pilot is telling the Phantom to fly itself directly home. In manual mode one is essentially flying a quadcopter with the technological assistance of several years ago, i.e., a bit of gyroscopic stabilization, but little else.
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