What is an APM based quadcopter?

APM, or ArduPilotMega is a an open-source autopilot and flight controller system for quadrotors and other vehicles with focus on autonomous behavior.

APM supports a very wide variety of quadcopters, multicopters, planes, rovers, helicopters and even underwater vehicles.

Just as other flight controllers, Ardupilot consists of a hardware +software part. Even though the hardware’s development was stopped a few years ago at version 2.8, it’s still a viable choice for basic autonomous behavior. For up-to-date and high performance hardware that can run the Ardupilot software stack, check out the Pixhawk family. The Ardupilot software is still under active development.

Compared to other flight controllers,the Ardupilot hardware is a good choice if you want to get a decent flight controller with some autonomous capabilities – the Ardupilot is the proven work horsefor this uses-case.

One of the most interesting things the APM can do is probably the automatic return home and landing capability, for example the Ardupilot can be programmed to return home when it loses the transmitter signal. Normally a quadcopter would simply shutdown and crash if it happens.

Other use-cases include way point based flying, geo fencing, and the Ardupilot is usable for higher-level tasks too including mapping and search-and-rescue.

While the APM 2.8 hardware makes a great all rounder, for best autonomous flight capabilities switching to the Pixhawk hardware platform is a great idea. Ardupilot supports the whole Pixhawk line, including the Pixhawk 2 and the Pixracer too.

The Ardupilot software + hardware combination is great for DIY projects, as it offers more flexibility than what you’d get with the other flight controllers.

The Ardupilot web page itself can be a great source of inspiration for your DIY project, and you can get both the controller itself and kits from Amazon.

Ardupilot supports a really wide range of vehicles – some of which you probably never thought could exist!

The more common vehicles supported by Ardupilot are planes, helicopters,rovers (cars), tri- , quad- , hexa- and octacopters.

The less common vehicles:

  • Single- and coax-copters (these are much like helicopters, but theyhave fixed blades, and use control vanes for navigation).
  • Quadplanes: Quadcopters crossed with airplanes. These aircrafts can take off and land vertically, but will fly like a plane once the get up in the air.
  • A harvesting tractor was modified to support autonomous behavior with Ardupilot.
  • Antenna tracker: the Ardupilot can be set up as an airplane-tracking antenna unit. This way you can have a lot longer range than you could have with a simple antenna.
  • Ardupilot supports submarines too.

Using the APM for quadcopters

The Ardupilot makes a great flight controller for all the use-cases you can dream up for your quad. It’s used for just flying around, FPV racing,aerial photography, and autonomous missions too.

Even if you just want to fly around, Ardupilot’s extra features can come very handy, and could even save your quad from crashing.

Ardupilot features which make flying easier and more fun

The Simple and Super Simple modes work like the headless mode.

A lot of quadcopters (including a few toys) support headless mode. In this mode no matter what direction the quad copter drone is looking, using the forward stick will make if fly away from you, using the left stick will make it fly to the left. This mode is very useful if you lose orientation however it’s not much fun to fly this way.

The Ardupilot supports stabilize mode,

even combined with altitude hold. In this mode the stick input simply determines the roll and pitch angle of the quadcopter. If you center the stick the quad will level itself too. If you combine this mode with altitude hold mode, the quad will hold it’s altitude even while accelerating forward, and will ascend or descend only if you move the right stick up or down from the middle. This is the mode that’s both very beginner friendly and fun to fly around.

Ardupilot supports sport mode

, even combined with altitude hold. You can think of this mode as “acro light” – the sticks control the rate of rotation, however the quad will not lean more than the maximum angle you set up. Altitude can be held just as in the previous mode.

Acro mode is the same as the rate mode of other flight controllers.

In acro mode the quad will not self-level, altitude loss is not compensated,and the stick input will be interpreted as the angular velocity of the axisin question. For example the more you push the left stick left, the fasterthe quad will keep leaning left. Even if you pull the stick back to thecenter, the quad will lean left (and fly left) until you compensate bypulling the stick to the right. This is the hardest mode to fly in.

Geofencing is way to keep your quad “fenced”.

If a geofence is activated, the quad will not be able to break out of the fence. This mode is handy if you want to make sure your quad never flies away and stays in your line of sight.

Ardupilot supports return to launch mode.

When you activate the RTL mode from your transmitter, the quad will ascend or descend to a preset altitude,then fly to the takeoff location while holding the altitude, and finally it will slowly descend. This is a great way to get your quadcopter back would you lose orientation.

Ardupilot has a brake mode.

When you activate this mode from your transmitter, the quad will brake down and will start holding it’s position. The stick input is cut off at this point, and you’ll have to turnoff brake mode to get back the controls. You can think of this mode as a panic button and can save your quad from a crash.

Autonomous flying

Ardupilot has two main mission planner components

, the APM Planner and the MissionPlanner. Besides these there’s also the Droidplanner 3 / Towerapp for Android.

The Mission Planner and the Tower app support waypoint based flying, smooth flying using curves between the way points, survey mode to automatically survey an area and other modes too.

Both the Mission Planner and the Tower app supports pointing the camera to a preset location.

The Tower app has a “follow me” too, in this mode the quad will keep following you with the camera pointed at you while you are moving around.

Besides these the Mission Planner supports multiple “rally points”, which are designated landing locations. In case of a mishap, the quadcopter drone will select the nearest rally point and land

APM sample project and kits

450 size quad with Ardupilot

Ardupilot is great for DIY projects, you can use it to power almost any quad you’d like to.

There is a great post over at first quadcopter.com on using the Ardupilot with a DJI F450 flame wheel kit.

The takeaway of the article are that you can cheaply build a quad that’s performance rivals the commercially available drone’s performance. Tobe honest some luck is required if it’s your first build (click here to learn more about building your own quads).

The main sticking points were the badly aligned screw holes in the frame and the lack of documentation – these are fairly usual when building your own quads.

The components used:

All in all the complete kit is much like this one.

You can get the Ardupilot components online:

The software is available for download here, the stable builds for multicopters are here. Either select your hardware there, or click here for the APM 2.x hardware builds, or here for the Pixhawk builds.

Getting the hardware is easy too, as you can find APM2.8 flight controllers, Pixhawk clones, Pixracer, and even quadcopter kits (without transmitter and receiver) online.

Have fun flying πŸ™‚

What are mini and nano quadcopters?

Foreword – quadcopter size

Quadcopters come in all sizes you can imagine, from the huge, 6 kilogram HammerX8 to the tiny 11 gram CheersonCX-10. Quadcopters are usually classified by their diagonal motor-to-motor size in millimeters:

  • The Eachine Racer 250 is a nice 250 size FPV quadcopter.

    250 size quadcopters, which measure 250 millimeters from the front left to the rear right motor are usually used for FPV racing. They are nimble and due to their lower weight do not crash as hard as a larger quadcopter would. They do not fly so well in high winds, and have a flight time of 15 minutes top, 10 minutes is more realistic. We recently built a250 size quadcopter, check it out! If you are in the US, size 250 and larger quadcopters may require FAA registration, as they usually weigh more than 250 grams. The Eachine Racer 250 is a really nice 250 size FPV quadcopter.

  • 350-380 sized quadrotors are intermediate quads mainly used to carry Gopro cameras: they have just the power required to lift a Gopro, while staying more nimble and less crash prone then the larger 450sized quads. The DJI Phantom 4is a 350 sized quad.
  • 450 size is great for Gopro or other light cameras. These quads are a bit sluggish compared to the 250 size, but they can lift more, have better wind tolerance and can fly for longer – up to 20 minutes. DJI’s Flame Wheel series features 330, 450 and 550 size quadrotor kits, Amazon has them too.
  • 650 size quads can lift even more, so they are good fit for large, professional SLR cameras.These will fly even in windy weather, but can come down really hard if something goes wrong. Flight time is 30+ minutes with these beasts. For a 650sized quad example, check out this Tarot 650 kit on Amazon.

These sizes are approximate, so a 250 size quad can be anything between 240and 260 millimeters diagonally. Using an approximate size helps classifying the quadcopters.

Electronics are getting smaller and smaller, so even 250 size quads can be fitted with a GPS and other advanced features – you do not need a large quad to have flight planning, location hold, or GPS based return home.

The Hubsan X4 H107Lmini quadcopter, fits in a hand nicely.
Mini quadcopters

are size 180, with ~180 millimeters between their motors diagonally. These quadcopters are great both for indoor and outdoor flying, their flight time is between 7 and 9 minutes. Mini quadcopters are usually used for flying around as form of recreation. A lotof these mini quads have cameras too which can be operated from the transmitter, so you can make a few good shots or record video with them.Some support WiFi based first-person-viewing too (the video is live streamed to your smartphone). These WiFi based systems are hardly reliable though.

Overall these quadcopters are good to have a bit of fun indoors or outdoors,while not costing as much as a 250 sized quad would. The Hubsan X4 H107L and the Holy Stone HS170 are great examples for this class.A nice upside of owning a mini quadcopter is that you will probably not need to register it with the FAA (though you’ll have to check the weight to make sure). The mini quadcopters come with the same interference-free transmitter technology as the larger ones, so you can fly together with others.

While these quadcopters have 6 axis stabilization, they usually lack advanced features, such as a GPS or flight planning. Their motors are usually of the coreless brushed type – these are simpler than the brushless motors found in larger quads, while providing more than enough power. Mini quadcopters are great to start drone flying, as they are really cheap and come ready to fly.

The Cheerson CX10 nanoquadcopter fits the palm.
Nano quadcopters

are class 100 quads, so their front left and rear right motors are ~100 millimeters apart.

If you look at them from the top, they would fit into a 7cm X 7cm box (with the props off). These quads are really tiny, and rarely weigh 20 grams. Such a tiny size has the drawback of lower flight time, around 4-8 minutes. Even though tiny, these quads can fly outside too if the weather is calm. Just as some mini quads,nano quadcopters can have cameras too, some even support WiFi based FPV.

These tiny quadrotors are great to have a bit of fun, seeing them zipping around is mind-blowing. As these quads are tiny they can barely hurt anything, so they make great gifts for children above 14 too.

Nano quads have the same interference-free transmitter technology as the larger ones.The Cheerson CX-10 is probably the most popular nano quad, and the Eachine E10C the most popular one with a camera. Get one to have some indoor fun – just as the mini quads they are cheap and need no assembly.

Dromida Ominus Review

The Dromida Ominus is one of the great looking quads on the market today, with a generous battery life of up to 12 minutes. These two qualities alone are enough to see that it’s a high-end product which will surely give you great joy.

The box contains everything for flying.
The box includes everything for the flight,

which is a plus compared to other products. Besides the quad, transmitter, battery,charger, replacement props and instructions it even has the 4xAAA batteries required for the transmitter.

The quad is 6 axis stabilized (3 axis for the gyros and 3 axis for the accelerometers) so the flight is super stable. Flips are supported too, and the Dromida Ominous is eager to show off at the press of a button.

The range is around 50 meters, but it depends on your environment, clear fields work the best for quad flights. Once out of range the quad will just drop out of the sky, so it’s best to push the limits while flying low.Flight height is limited by the range, so you will be able to push it up high.

The quad is fairly durable, though some users complained about soft motor shafts. But then again it’s a problem only if you crash it a lot.

Both indoor and outdoor flight is supported. The quad has four flight modes between beginner and expert, which is makes switching between indoor and outdoor flight easier too.

The Dromida Ominous comes without crash- and prop-guards, so it’s a great idea to get a few to protect your flying machine. Amazon has them for exampleΒ here.

The replacement main frame.

Replacement parts are available, which is a big plus. For example:

This quad was built for agility, so while it can lift some payload, it’s not really recommended. However fitting light object, like a 808 keychain cameraΒ works well.. The quadcopter handles wind like a champ, and can be flown really aggressively. Suggested ages is 15 years and up – one year higher than the average for quadrotors.

The quadcopter is available in green, blue, red and yellow colors. The colors have nothing to do with the frequency, you can fly two red ones together as the quadrotor uses the interference-free 2.4 Ghz technology. The colors together with the bright LEDs make orientation really easy.

While the quadcopter is advanced, it’s not advanced enough for automatic landing or return home, as it does not have a GPS. Headless mode is not supported either, for headless mode check out the UDI U818A.

The Dromida Ominus is 9.4 inches X 9.4 inches (238mm X 238mm) so it’s fairly large. The weight is around 100 grams, so you will not have to register it with the FAA. The large size and the geared propellers mean it’s not the quietest quad, however it’s not noisy either.

The box size is 14.8 X 9.7 X 3.9 inches , the shipping weight is 1.8pounds.

Video is not supported

by this version, however the Ominus has a variant with an FPV camera installed.

The stock battery.
The battery

is a 3.7V 700mAh Li-Po battery with a JST connector, the charger is USB based (works with iPhone chargers too). The flight time is up to 12minutes, with a charge time of 45 minutes, both of them are really generous.

The quad’s LEDs will start flashing when the battery is getting low, with plenty of time left to land.

Charging is simple: just plug the battery into the charger, the charger into an USB socket, the red LED turns on. Once it starts flashing you are good to go.

The quad comes with a single battery, but you can easily get more batteries for it. replacement chargers are available too.

The transmitter, flip button on the top left, mode on the top right.
The transmitter

uses the interference-free 2.4 Ghz technology, so it’s one less thing you have to worry about.

The transmitter is mode 2 only, which can be a problem if you are a mode 1pilot. Binding the quad to another transmitter is a solution to this issue.

The range is 50 meter for this quadcopter, and it will simply shut down once it’s out of range.

Pairing the quad and the transmitter is automatic, all you have to do is turn on the quad, then turn on the transmitter.

For some people binding does not seem to work, in reality the problem is the throttle trim is set all the way down. To fix the issue just raise the throttle trim until the quad is flying again.

Besides the usual sticks and trim buttons, the Ominus has a button for the flips, and a button for setting the sensitivity.

The quadcopter is only available with the controller.

Our rating:

The Dromida Ominus is fun little quadcopter.
Fun:β˜…β˜…β˜…β˜…β˜…
Value:β˜…β˜…β˜…β˜…β˜†
Looks:β˜…β˜…β˜…β˜…β˜…


You may want to visit Roger’s Hobby Center for another great review of the Dromida Ominus.

Syma X11C Aircam Review

The Syma X11C Aircam is a camera-equipped version of the well-established Syma X11. Just as it’s brother, it’s a well-built and great looking mini drone, which comes complete with a camera and crash guards.It has most of the functions you can expect from a quad rotor in this category:it’s 6 axis stabilized, can do flips on button press, has multiple speed modes, and the camera can be controlled from the transmitter too.The range of the X11C is around 30 meters, and it can fly just as high too.The quadcopter uses the interference-free 2.4 Ghz technology, so it will simply shut down would you fly out of range.The 6 axis stabilization grants the X11C a smooth flight, so you will not have to work the sticks just to make it stay on spot.

The box contains everything for flying, except for the 4xAAbatteries for the transmitter.

As the X11C comes complete with prop guards and bendable props, so it’s fairly well protected from crashes. Still, crashes occur but fortunately the X11C is very well supported, lot of parts are available for it, for example motor, gear, shaft and propeller bundle,propeller and prop guard bundle,body cover,motor cover and upgraded batteries with charger, just to mention the most important ones. For a complete list of parts click here.The X11C is fairly light and small (about 15 cm X 15 cm, weight is 36 grams) ,so lifting objects with it is out of question. The upside is that drones this small do not need FAA registration.Even though the X11C is small, it supports both indoor and outdoor flying.Besides making the X11C suitable both for beginner and experienced pilots,it’s low and high modes make indoor-outdoor switching easier too: low mode is better for indoor flying, while high mode is better for outdoors.The quadcopter tolerates small winds, however it can’t fight strong ones and could get carried away. So to keep your drone safe fly only in calm weather outside.The X11C lacks headless mode and one key return which is a minus, as it makes the quadcopter less suitable for beginners. For a quadcopter which supports headless mode you may want to check out the Eachine H8C. Automatic takeoff and landing, GPS, and night vision are not supported – butthen again none of the quadcopters in this price category have these features.The box contains everything you need for flying, except for the 4xAAbatteries. The box even contains a 2GB MicroSD card, however it does not contain a card reader.The package weight is 430 grams, and the size is about 36 cm X 9 cm X 20 cm.There is also another version of the packaging, which is about 20 cm X 20 cmX 15 cm in size. The X11C has brushed coreless motors and a gear drive, still it flies quietly so you will not disturb your environment. The suggested age group is 14 years and up. The quad contains small parts,so keep it out of the reach of little children. The quadcopter has LEDs which make it great for night flying. Even better the LEDs look downwards, so they are easy to spot. The propellers are direct-drive, so the Syma X11C does not make much noise.

Syma X11C video sample.
The video of the X11C

is a 2 megapixel unit, with a 1280 x 720pixel resolution. It’s fixed in place and it can record up to 20 minutes of video or 800 pictures onto the 2 GB MicroSD card. The video quality is better than it’s rivals’ and it records audio too -however the prop noise is just too much for that to be useful.The video functionality of the X11C can be controlled from the transmitter which is a plus.The video is non-fpv, so you can’t view the live stream, and you will not need a smartphone for this function. The videos are recorded in AVI format onto the SD card, so all players will be able to play them.To view the videos first stop the recording from the remote, next power off the quadcopter. Next remove the MicroSD card from the quadcopter and connect it to yourΒ  computer using a card reader.If you power it off before stopping the recording the video file will get corrupted and will not play.As the quadrotor is small it can’t lift another camera.

The stock battery is a 200mAh unit for a 5 to 10 minute flight time. Upgrades are available.
The battery

of the X11C is a 200mAh 3.7 volt LiPo battery,which gives the quadrotor a 5 to 10 minute flight time, after an hour long charging. Battery upgrades and replacement are available, and are great to have more fun with your quadcopter. For in-the-field charging you can use USB power banks too.The stock charger is USB based and works with any USB socket, even the iPhone charger too.To charge the battery first remove it from the quadcopter, next connect the battery to the charger, and finally the charge to the USB port. Charging is complete when the charger’s LED turns off.The battery’s plug is a standard JST plug, so a wide range of chargers and batteries are compatible with the X11C. Monster-sized 500mAh batteries are available too, which can give the X11C more than 11 minutes of flight time – just check the motor temperature often to avoid frying them.

The X11C’s transmitter.
The transmitter

of the X11C is game controller-like, exactly as the camera less X11’s transmitter. As such it does not really suit large hands.It uses the interference-free 2.4 Ghz technology, so you will be able play together with others.The range of the X11C is about 30 meters, and it will simply drop out of the sky if it gets out of range – this is how all the quadcopters which use the2.4Ghz spread spectrum technology behave.The X11C is a bit more open than other quadcopters, so it’s possible to bind the quad to other transmitters too. This may even extend the control range.The transmitter is in mode 2 by default (throttle on the left), however it is possible to switch between mode 1 and mode 2:first turn off the transmitter, and then turn it on again while pressing the rightmost trim button. This toggles mode 1 and mode 2, you can use the same sequence to switch back to mode 2. Binding the quad and the transmitter is simple:

  • First turn both the transmitter and the quadcopter off, and place the quadcopter on an even surface. Move the throttle to the minimum position.
  • Next turn on the quadcopter, and then the transmitter too.
  • Finally push the throttle up to the maximum and then down to the minimum again. This binds the quad and the transmitter.

If the X11C is drifting after a crash it’s time to recalibrate the gyros:first turn both the transmitter and the quadcopter off, next bind them. To recalibrate the gyros move both sticks to the lower right corner, and wait for the LEDs on the quad to turn solid.

Overall

the Syma X11C is a very popular durable quad,which suits intermediate to advanced pilots the best. The camera is highquality too and the spare part availability is exceptional. 5 star material.

Fun:β˜…β˜…β˜…β˜…β˜…

Value:β˜…β˜…β˜…β˜…β˜…

Looks:β˜…β˜…β˜…β˜…β˜…

Resources:

If you liked the X11C you will probably love the Syma X11and the Eachine H8C too. RC Groups has along thread on the X11 and X11C, it’s really worth checking out, it’s full of useful information.