Quadcopter project

[Skyfire]

Greetings,

 

Not sure if its ok to barrage everyone with questions straight after making an accoutn so i apologise in advance, it seems to be surpisingly hard to find an active uk based rc forum and there seems to be alot of knowledgeable people on here.

 

So heres my problem, im planing to write my own autopilot program intended for the ArduPilot Mega but i need a platform for testing and general enjoyment ive dabled with rc vehicles before but never in deth and onlky the little rtf toys from shops. So i have no experience with where things are good value or if im being ripped off, I have  around

[jony nitro]

Hi welcome have you flown before?

Link for Quad

http://www.ebay.com/itm/251392992318

Edited September 1, 2014 by jony nitro

[Skyfire]

Hi , thanks for the quick reply

 

 

Ive flown s few little RC battery hellicopters and have a small bit of experience with RC planes but thats about it, as im sure your aware cornish gorse isnt to forgiving.

 

Is the kit you linked to compatable with the Ardupilot board ?

[jony nitro]

Yep

What part of Cornwall

[Skyfire]

Tehidy near Camborne, unfortunately in Bristol for uni work though so open spaces and the like are harder to come by.

[Tamiyacowboy]

anything smaller than and including the 328 chipset ie: arduino uno/dev/ mini

just does not have the io ports and kb to hold the larger ardupilot code.

 

however the ardupilot is built around the arduino Mega boars with more io ports and extra horsepower

via a more stronger MC ( micro controller aka the chip running the show).

 

depending on size motor around 40-50 quid

frame anything from free to

[Skyfire]

Thanks for the reply Tamiyacowboy, i have to admit i'm a novice when it comes to building anything and it generally goes badly, Is there a recommended site to source parts / rtf kits from ? I had to choose the arduino as there's more support as you say and its hopefully a platform that wont drive me mad focusing on the main part of the project that is writing the autopilot software.

Thanks for the heads up on the counterfeit autopilots i will try and make sure its an original before spending money and will avoid hobykings own boards.

 

I just need a platform to work on the code with as little money spent as possible  but everywhere seems to have stock issues.

Edited September 12, 2014 by Skyfire

[Skyfire]

keeping everything suggested in mind i have come across the following , could anyone give their opinions on each ?

 

 

http://www.ebay.co.uk/itm/Quadcopter-multicopter-Motors-ESCs-props-ardupilot-mega-APM2-6-with-gps-fpv-/221545528486?pt=UK_ToysGames_RadioControlled_JN&hash=item3395247ca6

or

 

http://www.ebay.co.uk/itm/Quadcopter-kit-X-Mode-frame-Afro-ESC-MT2213-MultiStar-APM2-6-ArduPilot-NEO-6-GPS-/221539799550

still need to buy a lipo battery and reciever for each though :/

 

 

 

thanks for the help so far

[Tamiyacowboy]

To be honest. 

 

i been playing with multiwii aka ardupilot stuff for a while, and i can tell you with my hand on heart,

its a pain in the arze, i mean a right royal pain.

 

your more the designer builder programmer and pilot all rolled into one, and this is IN THE FIELD not at the desk.

some things work and some dont, take the magnetometers and barometers, so many different makes now and models

we find it hard to pin out one decent type. so the code changes a lot as new boards are released and old ones removed.

 

interfacing with the devices means both a programmin interface like arduinos scripting client and then a third

party application to show as a graphical output what is happening and the data feeds in and out.

your always tweeking the peramiters to gain that extra for a flight, be it batterys to set up the PID rates

or to just get the bird to hover. ( getting hover is not so easy, i lost 4 props my first 2 trys).

 

Starting out in the arduipolit world is really not for the newcomers, your asking your head to soak up huge amounts of infomation and

knowledge , your better to start with the lower class arduino based multiwii controllers ( its basicly anintendo wii numbcuck and dongle hack mod)

these have LESS peramiters and flashing code need. the most popular flight board to start with was and still is the hobbyking KK2.

a small 45mm square flight board with triple axis Gyro and triple axis accelermeter.

here you will learn how to use arduino to flash the code to and from the board, the pcb unit is populated with a small

lcd screen and 4 push tab buttons to allow user input so less need for laptops in the middle of the flight field/car/groundbase

 

Small frames are twitchy and agressive, big frames are more defined in flight and have the weighted feel something a newcomer will be more suited to.

motors we have good bad and ugly, emax aint bad , but sunnysky are the top dog with a couple other makes.

a good motor is key, its gonna last longer for a start and run smooth with less need to replace bearings every week or so.

 

I hate saying this to newcomers, but you do have to learn to fly. its not going to be easy and you will ...... no wait ..... YOU WILL BREAK THINGS.

you cannot TRUST electronics, they do and will fail at some point,  so again the cheaper way is to start with a simple and more easy craft to care for.

smashing up a gps then trying to source the same one is not easy. frying a board from a simple mistake is not an easy fix and will cost more to replace with new.

so the cheaper boards are a better choice. 
BUT dont get me wrong and i am not trying to put you off, so its better to start as a newcomer and grow with the hobby and technology that feeds it.

we all either started with a multiwii or KK2 and before that we had the toygrade quads costing like 30 quid. those taught us to fly with some control.

and still have lots of fun. these days the guys have upgraded and now fly ardupilot or naza based systems, run camera systems and use googles 

to fly by sight. 

 

 

so my best advice is start cheap, and grow with the hobby, build a small quadcopter so you can learn how they work, trust me

choosing your own parts and then putting them together to form a finished product is one big smile. you know those parts , where they came from

how they fitted into the craft and what they can take. when someone says where did you buy that from, and your reply is " i built it from parts myself " gives you

a warm fuzzy feeling inside and a ghasp from the person asking the questions.

 

this was my first ever quadcopter build i did using multiwii, others used the same type of setup and added the cheaper less technical KK2 and had so much fun.

the price for this build was

 

 

4x motors =

Edited September 12, 2014 by Tamiyacowboy

[Skyfire]

Tamiyacowboy , thanks so much for the help so far you have no idea how appreciated it is. I have had experience with embedded programming before interfacing with a 4 wheel based robot with bit masking and spent a fair amount of time on that , I basically have the next 6 months to design a program to interface with the quad copter and then get it to hover and eventually land. The plan for the first couple of months i think will be a retractable dog lead and a platform to test inputs etc.

Im hoping with the Ardupilot you can clear the code already on the board and write your own rudimentary code and go from there but if anyone can confirm this is would be appreciated. Unfotunately i am pretty tied into this idea as its for my final year project at uni and needs to be rather substantial but I am aware I'm taking on a big project that may or may not work in the end.

 

I appreciate the advice about starting slow and going from there and I wish I had made up my mind on this a year ago as I could of got all the practising out the way then. The plan is small steps and wont actually be going outside for a good couple of months.

Your setups look amazing and the route of having a camera on the front seems like so much fun, i just need to find a  good reliable set up as i think i can do a lot of testing using simulation software. The thing i worry about is the motor balancing and buying the wrong parts but helpful people like yourself give me hope i can possibly do this project after all.

[Tamiyacowboy]

ok first off have a look at the arduino site and its client, how the script is formed, then defined and uploaded.

 

using arduino means you can design your own applications to run the stuff, so you can take the data lines

and read them of graphicaly .

 

motor balancing is done via the controller, using both the feed data from the gyros x-y-z axis and the accels on the x-y-x axis.

this feed gives the AUTO level. 

add in a third feed say a baro, and we have vertical, this now can control the motors in the axis from gyro and accel.

 

to remove the wobbling effect as the motors try to keep up with each other we use PID to adjust the rate and sensativity of the added componets 

 

if all four motors sense that each axis is stable and it has enough rpm it will lift to a hover, the baro can be told to keep in a certain data area,

any deviation is sent to motors either slowing  and or speeding them up.

 

the most technical algorythms used will be for the return to home - failsafe funtion. here the craft will read a GPS on boot up and save the current location beacon.

it stores this untill failsafe is engage then it shifts to read and match current gps reading with the bootup file save, the craft flys itself back home.

in failsaife it uses its baro accel and gyros with the magnometer and gps to travel to a set return gps beacon save point, then engage a slow shutdown.

it will cycle using the baro to judge when it hits solid ground then disarm the system until user input is seen.

 

its all built into the multiwii arduino files and code, but its open so change by anyone. so you can add new devices etc etc, blue tooth, lcd displays

optical -IR - sonar based componets ( like robots 16 dof with gry accel and tilt metering).

take away the rc handset, add a PC screen and a laptop running the link software to a UHF transciever add a flight sim joystick,

you have a drone, thats not far from military likeness and ability, from consumer off shelf parts.

 

 

i would NOT write new code , but take the old Better it and add your own mark to it. but also design an application for public use

using whats already out in the opensource world. 

[Skyfire]

Thanks for yet another fast reply, i have been looking into arduino examples and hope to be getting some reading material in the future. Good to know about the motor balancing as i had read somewhere that it was tricky to setup so im glad its automated.The return to home algorithm is one i hope to implement myself as my projects main focus is an autoland program making use of the Ardupilots various navigational inputs as you've stated. Unfortunately adapting pre-existing code would make it rather difficult to improve or add features that would be enough for a good mark so i have to reinvent the wheel starting from scratch planning coding and testing etc.From there i can decide if i can take it further or not or at least hope its working in 8 months.

 

Any recommendation for a safe reliable site to buy parts from ?

[Tamiyacowboy]

i got most of my parts from a chinese website shop.

14days delivery wait from overseas, and it skipped through customs ( small orders )

 

the website in question : http://www.banggood.com/

 

my motors and multiwii board came from these ( btw multiwii can be flashed to act just like an arduino board aka Arduino uno - micro and will run the stock arduino scripting)

 

page three in this thread i show how to enable I2c on a certain brand board to gain gps data in-out lines and power to ground

not long after boards became populated with I2c headers. : http://www.msuk-forum.co.uk/topic/159767-everyones-quadcopter-build-ongoing-101-project/page-3

 

i think i also hsow how to upload and flash scripts to a multiwii board and show how to define code to enable certain make components like mag-gyro accel

[Skyfire]

Ok then so far i seem to have this :

 

 

1 x diatone 450 frame,integrated gold plated pcb..

4 x emax quadcopter motors 2213/935kv 

4 sets of 10x4.5 props..

4 x 30a simonk esc,flashed with latest firmware

lipo low voltage alarm

1 x apm 2.6 with external compass and gps module

 

now i just need a lipo and transmitter/receiver for it as far as i know and a charger for the lipo

 

is the transmitter  I linked previously from Hobby king any good ?

 

 

when dealing with lipos is there a specific type or something involved akin to aaa battery's etc, i understand the power to weight ratio is what dictates this but is there anything i should aim for ?

[Skyfire]

Finally received the copter parts in the post and got some good reading material but still need battery and transmitter suggestions