The Drone Thread

blade81

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For any beginner who wants to fly/play with a drone, i had just created a video here showing you how to control the drone using the remote control sticks.



Is that simple!, and you had just graduated from basic drone flying training after watching that video.

umm,... and now here's the course fee you need to pay, S$10 each person and please pay to my bank a/c here:
https://www.nkfs.org
or "Kidney Dialysis Foundation" also can, if you do not like "National Kidney Foundation"
http://www.kdf.org.sg


;)

Wah sweet! thanks for teaching me how to fly!:s13:
 

hwzlite

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'

Anyone recommendation for entry level?


and that very kiasu hwzlite uncle here will help you to squeeze all the drone values+features out of your every cent$ spent. :s13: :s12:

Ohhh..... almost forgot this free basic syma drone lobang mentioned by bro Jurong640 ( https://forums.hardwarezone.com.sg/hobby-lovers-229/drone-thread-5591208-7.html ) on attending this course http://skillshq.sg/eventtemplate.php?eventtemplate=10-Basic-Drone-Pilot-(CRS-N-0034961) :D
 

Quadcopter

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just ordered one piece, finger very itchy! ~S$99 after some promo code.
motor's gear will get worn down very fast and non-replaceable.
selfie photos are good, videos will need extensive stabilizing and cropped to 720p.

"curing itchy finger is something money cannot buy, for anything else there is always master card".... :(

c-me.png


(No remote control, handphone control only and not recommended for beginners)
 
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Quadcopter

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Understanding the drone sensors

Basic drones (Gyroscope+Accelerometer)
- Gyroscope: Stabilize the yaw position (meaning the drone don't keep spinning horizontally)
- Accelerometer: Stabilize the leveling position (meaning the drone don't slant/tilt and moving horizontally in random direction)
- These basic drones are mainly for racing purpose. Some drone pilots might even shut off Gyroscope/Accelerometer and flying in full "Acrobatic" mode. Example drones: JJRC H36
- These drone does not have altitude and positioning sensors so itself cannot keep it's altitude height and tends to drift in horizontal position.

Altitude Hold drones (Gyroscope+Accelerometer+Barometer)
- Barometer: Air pressure sensor to tell the height of the drone. Found to be cheap and working reliable on drones.
- Example drones: Syma X5
- For beginners, you need to pick a drone with at least these capability. It is not easy to maintain drone altitude if you are new to drones.

Position Hold drones (Gyroscope+Accelerometer+Barometer+GPS/Optical Sensors)
- GPS+Compass: GPS to tell current drone position and compass for drone to correct it's position error.
- Optical Flow sensors: This is something like your desktop optical mouse, having a small camera below to track position.
- Example drones: Hubsan H502x/H501x. DJI Spark, Yuneec Breeze. GPS operates at outdoor only, and Optical Positioning Sensors are good for indoor. Spark and Breeze have both GPS and Optical positioning sensors.

Obstacle avoidance sensors
- These sensors help to avoid the drone from ramming onto some objects and do not help in the basic stabilizing of drone in the air. Sensor types are Camera Visual Processing, UltraSonic, or Infra Red.

Auto-pilot Drones (Navigation software/firmware)
- Auto-pilot is mainly on application software level and does not need extra sensors. Drones are mainly GPS position hold drones, but market is moving towards using cameras to perform 3D terrestrial plotting/mapping.

~~~~~~~~~~~~~~~~~~
so, recommended drones for beginners I think would be something like:

S$50-200 range, with Optical positioning sensors: XK-X150, Rova Selfie,
S$50-200 range, with GPS outdoor: Hubsan H502S(500m), Hubsan H216a(50m)
S$200-300 range, with GPS+Optical positioning: Yuneec Breeze 4K(50m)

Beginners need both altitude-hold and position-hold to assist in drone flying. Without these drones capabilities you will give up of drone flying/playing very fast. After one had mastered the basic skill of drone flying, he could then move further to either racing drones (JJRC H36) or aerial photography.

I think currently Yuneec Breeze 4K (US$130 amazon), and Xiaomi Mi Drone 4K (~S$600) are value-for-$$ drones with 4K camera, and able to withstand windy outdoor conditions.

disclaimer: I only have hubsan H502s and DJI spark. I always wanted to buy a Yuneec Breeze. Reliability of all other drones "buy and try at your own risks" hor... I have limited drone knowledge also hor! ;)

~~~~~~~~~~~~~~
Problems of the sensors:

Gyroscope: working reliable, but gyroscope drifts and your yaw position also drifts after few minutes. Gyroscope cannot be use to replace accelerometer as there is not fix reference and it drifts.
Accelerometer: Working very reliable. It has earth gravity pull as reference, and able to measure inertia or acceleration. But you cannot use it to measure speed. Currently speed is measured by using GPS
Barometer: Works fine, but drones fluctuating air pressure caused by propellers is giving it some problem.
Compass/Magnetometer: Works reliable at outdoor environment only, as earth's magnetic field is too weak. You cannot use magnetometer to replace gyroscope for yaw control.
GPS: working outdoor only, and reasonably reliable. There are GPS/US, Glonass/Russia, and less using Beidou/China, Galileo/Europe of total 4 systems. Drones like DJI Spark is using 2 systems of GPS+Glonass so is much faster in getting the 3D-Fix positioning and more reliable.
Optical Positioning sensors: Market currently keeps improving on this technology.

Note: Flying your drones carefully and safely. When there is solar flare/storm, all sensors become dead regardless if drone is from DJI, Yuneec or Hubsan.... :s13:
 

hwzlite

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***sigh....*** After all these years of bells&whistles , still no market (hey dji what r u waiting for? ) capitalizing Quadrocopter failsafe algorithm: Recovery after propeller loss :




Incidentally , i recently experienced mid-flight brushed motor failure on my hubsan h502s, lucky drifted and crashed into tree branch with no damage. Now grounded still waiting for motor replacement... :frus:
 
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Quadcopter

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***sigh....*** After all these years of bells&whistles , still no market (hey dji what r u waiting for? ) capitalizing Quadrocopter failsafe algorithm: Recovery after propeller loss :

Incidentally , i recently experienced mid-flight brushed motor failure on my hubsan h502s, lucky drifted and crashed into tree branch with no damage. Now grounded still waiting for motor replacement... :frus:

aiya, very hard to do that on quadcopter lah!

problem #1: after losing one propeller, you need that diagonally opposite propeller to have bi-directional spinning capability to level/balance the quadcopter. And this failsafe is only useful for quick non-crash landing, no navigation.

problem #2: after losing one propeller, and when you shut off the other diagonally opposite propeller. That will cause the quadcopter to keep spinning on yaw. this failsafe is only useful for quick non-crash landing, no navigation.

problem #3: after losing one propeller, and shut off the other diagonally opposite propeller. You are flying on 2 propellers only, meaning you need to have >2x thrust. Only Mavic with 2.5x thrust can do that. But if you are emergency landing only may be spark with 1.9x thrust can do it also.

my mind getting too old and don't work that well, if someone ask me to do that, I will either:
a) construct a hexacopter, if one propeller down just shut off the diagonally opposite propeller. Then it becomes quadcopter and continue flies home safely.
b) construct a octocopter, if one propeller down just shut off the diagonally opposite propeller. The it becomes hexacopter and continue flies home safely. (Actually i think if you construct an octocopter and configured it as quadcopter, meaning each arm has 2 motors/propellers from one motor control, and having >2.5x thrust, I think cleanflight/inav might fly home safety without even noticing one propeller gone. cleanflight/inav's PID is able to adapt to big variation)

why people always suka suka like to torture own mind and think so complex one? :(
please make it simple life and simple mind lah! buy the cheapest drone, if crash liow go get another cheap cheap one... "旧的不去,新的不来"!! eh got new drone again hor... :s13:
 

hwzlite

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aiya, very hard to do that on quadcopter lah!

problem #1: after losing one propeller, you need that diagonally opposite propeller to have bi-directional spinning capability to level/balance the quadcopter. And this failsafe is only useful for quick non-crash landing, no navigation.

problem #2: after losing one propeller, and when you shut off the other diagonally opposite propeller. That will cause the quadcopter to keep spinning on yaw. this failsafe is only useful for quick non-crash landing, no navigation.

problem #3: after losing one propeller, and shut off the other diagonally opposite propeller. You are flying on 2 propellers only, meaning you need to have >2x thrust. Only Mavic with 2.5x thrust can do that. But if you are emergency landing only may be spark with 1.9x thrust can do it also.

... :s13:

LOL, RTFA that's is 1 fine engineering feats of Extreme situations require extreme measures , else we still in stone age :D :

""...
This new approach allows such a vehicle to remain in flight despite the loss of one, two, or even three propellers. Having lost one (or more) propellers, the vehicle enters a continuous rotation — we then control the direction of this axis of rotation, and the total thrust that the vehicle produces, allowing us to control the vehicle’s acceleration and thus position. Even if the vehicle can no longer produce sufficient thrust to support its own weight, this technology would still be useful: one could, for example, try to minimize the multicopter’s velocity when it hits the ground, or steer the multicopter away from dangerous situations such as water, or people on the ground....""
 
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Quadcopter

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LOL, RTFA that's is 1 fine engineering feats of Extreme situations require extreme measures , else we still in stone age :D :

""...
This new approach allows such a vehicle to remain in flight despite the loss of one, two, or even three propellers. Having lost one (or more) propellers, the vehicle enters a continuous rotation — we then control the direction of this axis of rotation, and the total thrust that the vehicle produces, allowing us to control the vehicle’s acceleration and thus position. Even if the vehicle can no longer produce sufficient thrust to support its own weight, this technology would still be useful: one could, for example, try to minimize the multicopter’s velocity when it hits the ground, or steer the multicopter away from dangerous situations such as water, or people on the ground....""

aiya, listen to my simple and limited engineering conclusion better lah
"if your H502S already had a motor failure during mid-flight, then it says time to upgrade your drone to H501A".... :s13:
 

Quadcopter

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Drone selection for beginners, some brief description here

Basic drones:
- Cheap quadcopter with Gyroscope and Accelerometer only.
- Pilot need to maintain the vertical altitude and horizontal position all the time, which is not easy.
- The tougher part is altitude control, which is the remote control left stick up/down handling in maintaining the altitude of drone. Most beginners will have the drones crash onto ceiling or keep dropping to ground. The beginners will give up of drone flying very soon.
- If you are capable of handling this, this will be very fun with all the drone racing and aerobatic stunts.
- Cheapest and most fun is JJRC H36 of about S$17 (variants are Eachine 010, Furibee F36 and etc). JJRC H36 not recommended for very new beginners, but recommended if you want to further training your drone manual flying skill.

Altitude hold drones:
- This drone is with altitude hold using barometers. The drone knows how to correct it's altitude error/drift by itself.
- The drone keeps it's altitude. Meaning if you leave the remote control's left stick at the center or untouched, the drone will hover at the same altitude height, until you move the left stick up/down.
- Altitude hold drone is much easier for beginner to fly, beginner normally only need to take care of the horizontal position drifting of drone (the drone will slowly drift horizontally in any direction as there is no position hold). Beginner will only need to push the drone horizontally back a bit once it has drifted to too far or hitting something.
- Note that it is important to buy this type of drone came with remote control (gamepad, joystick commonly called "transmitter") and not controlled by handphone. Beginners will have difficulties controlling these drones by handphone.
- Example Altitude hold drones: Syma X21

Position hold drones, Optical positioning type:
- All position hold drones will have altitude hold/barometer already built in. In addition, optical positioning drone will have horizontal positioning capability. Meaning if the drone pilot leaves both the control sticks (of remote control transmitter) at the center untouched, the drone will hover at the same spot in the air. The drone knows how to correct both it's vertical altitude error and horizontal position error/drift.
- I'm suggesting these type of drones for beginners. It is much easier to fly. If you leave both the remote control sticks untouched, the drone will hover right at the same spot in the air.
- It is quite OK to have handphone control for these type of drone. These drones are very stable and seldom drift.
- Optical positioning has operational limits of up to about 5m height maximum.
- Example Optical positioning drones: XK-X150, Rova Selfie, DJI Tello/Spark/Mavic, Yuneec Breeze, Mi Drone 4K

Position hold drones, GPS positioning type:
- These drone has the horizontal positioning sensing by GPS. The drone will try to stay at some fixed horizontal location (horizontal position error correction) using GPS.
- You cannot received reliable GPS indoor, so all these GPS drones are mainly for outdoor flying. And with GPS, the drones can have auto-pilot capabilities like "return to home", "orbiting", "way points", and "follow me"
- GPS has ~1m of position error, and there are other problems of low GPS data feed (5-10 per sec), and poor reception. Together with windy Singapore outdoor environment, these GPS errors sometimes might cause the drones to "swing/circle" around one fixed point instead of locking steadily to that GPS point. In other words, these drones sometimes could sway to quite far apart even in GPS position hold. So for beginners it is better to have remote control for GPS drone. Do not use handphone to control GPS drones as you do not have enough time to react.
- Example GPS drones: Hubsan 501x/502x, DJI Spark/Mavic, Yuneec Breeze, Mi Drone 4K, C-Me Selfie. Note that DJI Spark/Mavic, Yuneec Breeze, Mi Drone 4K have both GPS and Optical positioning sensors.

Wifi controlled drones, and it's limitation:
- Wifi has it's own problem of communication overhead, congestion and lower transmission power limit.
- if you are using handphone to control the drone, you will have higher chances of slow reaction and drone crashes onto something.
- Only use handphone to control those very stable drones, for e.g. DJI Tello, DJi Spark, Yuneec Breeze. For other Wifi drones you have to be more skillful and not for beginners.

Indoor drones:
- For flying indoor, the drone has to be small (90mm motors distance diagonally, or smaller)
- Optical positioning preferred, and GPS will not work indoor.
- Indoor drones will have problem flying in the windy outdoor environment here.
- Example Indoor drones: DJI Tello, XK X150

Outdoor drones:
- For flying outdoor, you need to have powerful brushless motors and larger propeller size of 3"
- Optical positioning sensors will work for altitude up to few meters. Beyond that you need GPS.
- For drones with handphone Wifi as remote control or video display, you have flying range of 50m away.
- For drones with some proprietary remote control and video display transmission, you have flying range of up to few km away.
- Example outdoor drones with brushless motors: Hubsan 501x, DJI Spark/Mavic, Yuneec Breeze, Mi Drone 4K, Bebop 2.

FPV drones:
- FPV drones are video-piloting, meaning you are looking at video feed when flying (camera is installed on the drone), and flying like as if you are sitting at the cockpit of the drone.
- Most FPV drones are racing drones without altitude and position hold. So for beginner it is not advisable to get FPV drones as this is difficult to fly (this is not like computer simulation games).
- Beginners should get a JJRC H36 first to train your own skill. And move on to FPV drones later, or simply mount a tiny camera onto your JJRC H36.

Selfie Drones:
- For selfie photos purpose, need to get drones with at least some 5-12MP camera.
- I think these drones are producing good quality photos, and non-fisheye: DJI tello, C-Me selfie, Rova Selfie.
- For any drones with fisheye camera, you need to de-fish the photo on desktop computers (meaning digitally correcting the lens distortion on desktop computers). All hubsan drones are "fisheye"

Video Drones:
- For any video drone, better make sure it has a MicroSD slot on the drone. DJI tello's video is recorded on handphone through Wifi. Recorded video has problem of low bit-rate, drop frames, and some "mosaic-effect".
- For Yuneec Breeze, you need to perform additional video stabilizing processing on desktop as the drone does not have powerful electronic image stabilizing.
- For Bebop 2, it does not have mechanical gimbal so you should expect the video to be slightly more blur.
- For cinematic videos producing, need to get at least a dji spark, dji mavic or xiaomi mi drone 4K. Mechanical gimbal is a must have.

~~~~~~~~~~~~~~~~~~
There are other things to consider like size, reliability, durable, flight time, battery parts, 3rd party apps, repair, etc and I'm not going to describe here.

Due to the limitation in airborne weight, and product price, there is no single drone that could cover all the features you wish. And you just have to make the selection based on price/performance. For beginners' very first drone, I would suggest XK-X150, Hubsan H216A, DJI Tello or Yuneec Breeze.

It is very hard to hit the bull's eye and get the drone you like from your very first purchase. Suggestion is to buy something cheap first, and purchase "that right one" after you understand drones limitations, capabilities, features and also understanding your own needs. You might pay for the expensive S$2K MavicPro/Phantom4 in your first buy but later found out not many places to fly those powerful drones in S'pore,... and ended with a second buy of S$17 JJRC H36 having so fun of flying it indoor anytime.

My dream drone as dji tello with MicroSD slot.... but real dji tello got no MicroSD slot. :(


:s8:
 

hwzlite

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aiya, listen to my simple and limited engineering conclusion better lah
"if your H502S already had a motor failure during mid-flight, then it says time to upgrade your drone to H501A".... :s13:

Cannot lar if u r from a engineering background, tackling specifically on quad 4x rotors issues. Ofcos >4 multirotors config r known to be more resilience. :D
 

Quadcopter

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S$99 C-Me drone. Just received it few days ago.
(Not recommended for beginners)

Overall this drone has good camera and stable with GPS. This should be good for hiking, outing, and picnic, if you just want to take some aerial selfie photos. It produces 3264x2448 photos and photo quality is as good as a S$200 xiaomi handphone.
More technical information inside comment sections of youtube video.



C-Me drone (GPS):
- With GPS, stable at any altitude outdoor as long as no strong winds
- It has same problem as Hubsan drones, spending 3-4min on compass calibration and GPS reception/3D-Fix before it could take off.
- Unable to perform horizontal position hold indoor, as GPS is not available indoor or near buildings. Do not buy this drone for indoor or fun/aerobatic flying.
- Camera looks better than Hubsan.
- Will be difficult to repair and finding the parts

DJI Tello (Optical Positioning):
- Stable at indoor or outdoor at low altitude, as long as no strong winds
- Optical positioning normally has limit of 5-10m altitude (I cannot find range for Tello yet)
- No need any calibration or 3D-Fix before take off. Could perform immediate take off.
- Should be easy to change the brushed motors.
- I do not have a Tello now.

DJI Spark (with both GPS and optical positioning):
- Stable at indoor or outdoor, and at any altitude, and able to handle windy condition
- Takes only 20+ seconds from powering up to hovering in the air, whether you startup with gesture control or remote control.

C-Me drone, My usage:
If I have some plan for aerial photography, I will bring my spark out packed inside my backpack. For other times cycling around, I will keep this C-Me drone as standby camera for any aerial photos. This C-Me is smaller than a packet drink and fits nicely inside my bicycle's front pouch. I will still need a dji tello for indoor but tello is too bulky for outdoor cycling.

Have fun flying your drones! ;)
 

hwzlite

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S$99 C-Me drone. Just received it few days ago.
(Not recommended for beginners)

Overall this drone has good camera and stable with GPS. This should be good for hiking, outing, and picnic, if you just want to take some aerial selfie photos. It produces 3264x2448 photos and photo quality is as good as a S$200 xiaomi handphone.
More technical information inside comment sections of youtube video.


C-Me drone (GPS):
- With GPS, stable at any altitude outdoor as long as no strong winds
- It has same problem as Hubsan drones, spending 3-4min on compass calibration and GPS reception/3D-Fix before it could take off.
- Unable to perform horizontal position hold indoor, as GPS is not available indoor or near buildings. Do not buy this drone for indoor or fun/aerobatic flying.
- Camera looks better than Hubsan.
- Will be difficult to repair and finding the parts
;)


Incidentally new review from Quadcopter 101 as well :




Pros
- Folds to a compact size for easy portability in your pocket.
- Includes GPS and altitude hold for stable outdoors flight. GPS provides position hold, follow me, point to me, 360 degree pan, and return to home and landing capability.
- 1080p video camera and 8 MP still picture capability. - Camera parameters can be modified via its app. Modifiable parameters include White Balance, Exposure, Brightness, and Conrast.
- Video is recorded to onboard microSD card at 1080p resolution, and also recorded to your phone at 720p resolution via WiFi. - 2S 7.6V built-in battery provides over 8 minutes flight time per charge.
- In flight FPV video is viewable on your smartphone via its "C-me Camera" app available on Play here https://goo.gl/4WAJyu and iTunes here https://goo.gl/bXTZHy
- Can also share video and photos directly to social media through the app.

Cons
- 8 MP still pictures appear to be interpolated from screenshots of the 1080p video.
- Follow me performance is not the best. Can either be slow or jerky in its response to your movement.
- Battery is built-in. Can not be replaced in the field. Instead drone must be recharged via micro USB port before next flight is possible.
- GPS performance is verysensitive to compass calibration. App calibration procedure can be problematic if placed near the ground. It's better to conduct compass calibration at least 1 meter above the ground and metalic objects to reduce potential of interference with calibration.
....


 

Quadcopter

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- 8 MP still pictures appear to be interpolated from screenshots of the 1080p video.

I think got 8MP camera lah!, Raw photos taken by C-Me as below (Hosting website might re-compress image files to smaller, FB/Google/Youtube doing that). But for videos you will need to buy at least a dji spark, not C-Me drone. ;)

Anyway C-Me drone not for you, you should be upgrading your H502S to H501A. And C-Me drone not recommended for beginners also.

CMe01.jpg


CMe02.jpg


CMe03.jpg


CMe04.jpg



(Photos good enough, but ISO/Shutter speed, and Dynamic range not that perfect)


:s8:
 

Quadcopter

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haha, sorry, I cannot post 3264x2448 photos, the 4 images in previous post had been re-scaled to 1067x800 by the hosting website. File size also changed from 4.5MB to 208KB.... :s13:

go buy a C-Me drone and try it yourself, if you do not trust me... :D
 
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