From a diy Arduino quadcopter to a versatile octocopter flight controller.

[@manuel5038]

It's 2019 and I just bought all the parts for your quadcopter! Thanks for your amazing guide! :)

[@SeanKreck]

Holy crap you are a very smart person. I have been watching these videos and have learned more physics than I ever thought I would. Amazing skills man!

[@joeprince7509]

Really exciting to see the progression Joop, congrats on the maiden flight! You can tell how much hard work and careful thought you've put into it. And not to mention, that is one badass flight controller...

[@selimoztunc]

You are an inspiration to all the makers around the world. Your videos are by far the best ones about building an UAV. Simply perfect! :)

[@maximilianobarac8066]

Joop Brokking your are amazing man !! i've watched all your quad videos & they are extremely helpful and very teaching , i started studying everything from scratch in order to make my own quad , even my own communication system with nrf240l1+ modules , i have now all my components working separately , motors pwm's generation with 1 micro , the communication with nrf240l1+ ,and recently could get to work the mpu6050 readings, now it's time to get all the parts together but i had no idea how to transfer or interpret in code the mpu6050 accelerometer & gyro data in order to modify the pwm's signals , now i have thanks to you much more knowledge to accomplish the goal , infinite thanks to your generosity !!

[@Joop_Brokking]

Thank you for taking the time to write this message. Great to hear that my videos helped you!

[@agentbertram4769]

Seriously impressive. I will take a look at your website with a view to making one myself. It would be the project of a lifetime! Thanks.

[@martevdb4236]

Dank je voor alle hulp, ik heb mijn eigen drone/quadcopter gemaakt en je video's gebruikt om de code te schrijven. Hij vliegt en ben de code verder aan het verbeteren. Zonder je hulp had ik dit nooit geprobeerd, dank je!

[@PiefacePete46]

Absolutely STUNNING! An inspiration for us mortals... Thank you.

[@electronicprojecttutorial]

you are my inspiration Joop Brokking

[@waqasaps]

me 2

[@warrenreif5369]

Wow, what a talented engineer you are; very impressive. Great work and I don't mind your accent either. :)

[@Joop_Brokking]

Thank you for writing this positive comment!

[@tusharmaurya1668]

The ending footage was so satisfying to me!

[@samuelbetances4422]

That's a wonderful flight controller you have built, and truly inspiring to many of us; especially the GPS algorithm which is outstanding.

[@nyanfpv3179]

Where can I find the code? Especially the GPS and altitude hold algorithm..

[@chadman2275]

impressive staying true to the roots of our hobby

[@yungsloth8336]

wow, now just imagine rigging this copter with a camera for a live stream with a VR headset! It'd be amazing!!

[@dipanjanmaity6614]

You are a genius sir It's really very impressive

[@bethanyhunter5884]

Joop you're a freaking wizard

[@jimbobillybob1959]

WOW so cool. Outstanding engineering!!

[@sanjayprajapati-nf6nk]

I am amazed with your hard work.

[@sulymanalouf2889]

I can't understand why 13 people disliked the video! You are amazing sir, I wish you were my teacher I really wish that but unfortunately Syria is not the place where someone like you could be found . have you ever thought about making a complete course ,like how to make the flight controller and how it works from A to Z it will be very helpful and easy for us to learn and I really want to spend my saving to get the course ,cause I'll be learning 10X faster with your help I am studying in two universities at the same time BSc in Physics and Communication Engineering and working as a robotic trainer at the same time ), and maybe in the future you could make rockets and a satellite and fly them to LEO it really could be great

[@Joop_Brokking]

You can check out my play list here: kzbin.info/aero/PL0K4VDicBzshwCpUHzIB6hOLQVkDFHbxC And my website here: www.brokking.net/ymfc-32_auto_main.html Should give you a good start :-)

[@TheTechnocrat]

hay joop brokking!!! you are awsome...i am presently building your YMFC quadcopter and you are the best...thumbs up!!!!!!!

[@Joop_Brokking]

Thank you for the compliment!

[@hosom10001]

awesome work ! from one success to better one .

[@BarefootBeekeeper]

Excellent work. I will attempt something similar soon.

[@eric_hallstrom]

I'm so glad i stumbled upon your channel youre awesome

[@Joop_Brokking]

+Eric Hallström Thanks

[@Mk98788]

this actually flys better than my apm and dji

[@GaryMcKinnonUFO]

Lovely build. I'd be interested in seeing how you automated the Proxima.

[@jparun36]

Great effort!... Even I want to be able to learn and build such copters. motivating..

[@shaqibarsalan680]

you are awesome Joop Brokking !!

[@theorder-epicmusic1234]

Hi - can you suggest where I can get details to build large drones? Willing to pay for help :)

[@DocMicha]

Very nice Build and video, Thank You

[@MrFlashgrenade]

I can but stare in awe...

[@maher7241]

great work .... nicely done ... I just wanna say something... this channel is worth to subscribe. Waiting the tutorials for make one of these ... peace

[@GaryTaylorvw]

Would be great if you shared the code / list of parts needed and instructions how to build, I’d buy the guides.... so many people on here showing off how they make their drones but won’t share how to make them

[@smcfadden1992]

I really feel like you could make a octocopter look like a ufo with the right body pieces with the right venting

[@smcfadden1992]

Or get one of those adrino hexapods and attach that to the bottom of a hexacopter lol and have a hexacopter that could walk

[@supercobrapro7470]

Great video 👍

[@randysonnicksen9475]

Actually I think it's even simpler. If you use the default function of I2C1 (not I2C2) that is on pins B6/7 of the blue pill. Move ESC's to A6,A7, B0, B1 (T3C1-4) Use PB10 (TX3) for sending telemetry data. Thoughts?

[@iforce2d]

very very nice. are you using any sensor fusion in the GPS hold?

[@Joop_Brokking]

+iforce2d Hi Chris, in this video the barometer is used for the altitude hold and the gps for position hold. So no mixing with the accelerometer or gps for the altitude hold.

[@iforce2d]

+Joop Brokking Would you care to share any tips on the auto-take-off and auto-land? With standard Cleanflight I tried simulating a naive auto-take-off manually by switching to GPS hold before take off and immediately giving it about 80% throttle for a few seconds without any other stick input or manual corrections - it's very crude but this seemed to work as long as the ground is clear and level, although I will make sure to stand a long distance away if I ever let it do that fully automated! For landing I suppose you can descend slowly and check the barometer reading for changes, and perhaps also take into account the accelerometer values for signs of a sudden bump? Hmm... perhaps the take-off should also check the baro to decide if it is clear of the ground... and only then start doing GPS hold. The problem I found though was that if it starts doing GPS hold while still on the ground the correction value grows and grows, so that when it does finally lift off it swings very quickly in that direction. On the other hand if it does only pure auto-level at first, it will be pushed by the wind. I'm not so sure that a 'smarter' method would give any better results than just blindly doing 80% throttle for a few moments.

[@Joop_Brokking]

In short: I set the altitude setpoint to -4 meters. After that I rapidly adjust the altitude setpoint to approx 7 meters. When the controller thinks it is 4 meter to high the motors will run slow enough for a nice start. When the setpoint is adjusted the motors spin-up and finally the multicopter takes off. Works like a charm ;-) Auto land is just lowering the setpoint At a certain point. let's say -4 meters the motors shut down. It thought about the 'bump detection' but never liked the idea. What happens in bad weather with lot's of turbulence. I'm going for save rather than fancy. Besides that, I'm only using auto land a a fail safe feature.

[@razbotics]

Joop Brokking sir how did you acheived so accurate position hold with gps n without sensor fusion i was expecting an extended kalman filter being implemented in your project.

[@supercobrapro7470]

Hi, What I'm intending to use is following, 6 Hobbywing X8 Motors According to website the specs of this motor are Hobbywing X8 Motor( integrated ESC) Specifications: Max. Thrust 15.3kg/Axis (48V, Sea Level ) Recommended LiPo Battery 12S LiPo Recommended Takeoff Weight 5-7kg/Axis(48V，Sea Level) Combo Weight Motor+Propeller 1040g Waterproof Rating IPX7 Operating Temperature -20℃~65℃ Motor Stator Size 81*20mm KV Rating 100KV Bearing NSK Ball Bearing (Waterproof) PWM Input Signal Level 3.3V/5V (Compatible ) Throttle Signal Frequency 50-500Hz Operating Pulse Width 1100-1940 μs (Fixed or cannot be Programmed ) Max. Input Voltage 52.2V Max. Input Current (Cont.) 80 A(w/ Good Heat Dissipation ) Max. Peak Current (10s) 100 A (w/ Good Heat Dissipation ) Propeller Diameter&pitch 3090 Weight 180g Flight Controller: Pixhawk 2.4.8 Weight 200g PDB EFT 480A( Available on AliExpress) DIY Hexa frame Weight 6kg Required payload capacity excluding the weight of Hybrid generator: 10kg Now the question is how much powerful hybrid generator should i use to get all this setup running? Obviously I'll have to make power generator on my own too. So what engine and alternator should i use to get this setup all going on smoothly. My required flight time is about 30 to 45 minutes. So please help me. Is this all setup good? Should i go for 40mm props? Would it work as I'm expecting? Do i need any changes? Any kind of suggestion or advice on this is absolutely welcomed

[@randysonnicksen9475]

Joop. I think you could send telemetry data using a USART pin. I'm looking to copy portions of what you have done with the STM32. I've reviewed the code for autonomous quadcopter and I noticed that the telemetry TX output from the STM32 used a standard digital output, and you write code using delaymicros() to send the bits and bytes one at a time. It got me wondering why you did this. I started looking at the pinout of the STM and the alternate functions and I think I came up with a way to be able to use a USART channel to send the telemetry data. Move the I2C from B10/11 to alt function pins B8/9 (SCL1, SDA1). This makes B10 available for TX3. But B8/9 was being used for ESC outputs, so move ESC outputs to A6,A7, B0, B1 (T3C1-4) This whole alternate function and remapping is quite confusing to me right now, and I'll need to play with it, but what do you think? Will this work? Each byte of data you are transmitting to telemetry takes about 1 msec which is 1/4th of your scan time. If this could be offloaded to a USART you would have more time to do other things.

[@dtpc_technologies]

Even if you managed to use a USART, the delay would still be the same! Since Serial.write() will also block the code for 1ms until it transmits all the bits.

[@randysonnicksen9475]

@@dtpc_technologies Dang! Is that true for the STM32? I understand the STM32 is capable of "multibuffer" transmit and receive using DMA access. I don't know if the Serial.write() instruction supports this. I can't understand why the Serial library was written this way (blocks the code while data is xmtting) and doesn't use interrupts to service the communication.

[@dtpc_technologies]

@@randysonnicksen9475 I don't think that the Serial.write() supports this, since the stm32duino was made to resemble Arduino programming as much as possible.

[@stefanbachrodt7072]

Fantastic work! She looks so stable in the air! Would you happen to be interested in building something for long duration flight?

[@harsharunansh1862]

can you provide a list of the things please I want to make it as school project please reply ASAP

[@thangpham5806]

awesome project

[@anuragrajpoot17]

great work sir!!

[@drones7838]

I have a hardware question. Would appreciate if you would consider responding. I am wanting to put a hexacopter together. I would like to use my DJI Air Unit, V2 Goggles & DJI Controller ( big brick one ) ( Mode 2 ). Here is the question: Is that system, namily the controller I have, the DJI Brick Controller, Compatible with the flight control A3? Or any of the flight controller that uses GPS. Thanks

[@Donatillo1961]

wow wow wow ! can you make a book on step by step wiring ? and products ?

[@Joop_Brokking]

I can offer you this: www.brokking.net/ymfc-al_main.html I'm currently working on a 32bit flight controller code: kzbin.info/www/bejne/gHe2d5WJnJWfaK8

[@rpraver1]

As always great, when will we see details?

[@eyal4]

hey Joop great work, can you direct me to a place I could learn how to read the Sbus signal from the receiver with the arduino/teensy ?

[@natnaeltsegai485]

What is in between the big and small circles on the power distribution board?

[@AndresTorres-nm9xl]

Very nice!

[@neighbourpower3300]

brilliant, sir.

[@mr.ismayilovh]

Can you share used components name? Love you bro ♥

[@MultiPwolf]

I'm not really qualified to talk about this, but couldn't you get a more stable hold using a gyroscope sensor instead of the gps? Really cool video and inspires me to try and get into some stuff soon.

[@deGoodMe]

gyroscope is used to keep things in horizon level, while hold means staying in a coordinate of certain x,y,z provided by gps value. so both need to function.

[@klaus9503]

Do you use kalman filter? And how do you filter gyro/accel data? Looks very stable!

[@francoisBonin-phils]

Very nice video, i have started with a home made quad , then Hexa ,then i am planning an octo (500) , using the same material , adding 2 motors.I am fighting against the weight using carbon fiber/Styrofoam sandwich.i do not have knowledge in F.C software , so i use a pixhawk.why did you make the feet so long, for the cam?

[@EurianMaster]

Very good, you can download the complete project?

[@jortevers234]

Beste Joop ongelofelijk dat je dit allemaal zelf gemaakt hebt. Ik heb geen RC zender/ontvanger , is er dan een andere manier om toch de multicopter te kunnen besturen? Zo ja, wat zou dat dan kunnen zijn. Mvg, Jort

[@dappa211]

can someone please tell me how the helicopter was able to fly vertically without hitting the ground

[@sreekumarp2205]

can share details (code ,circuit and all) about this flight controller

[@SentinalUAV]

great job

[@Life-ze1no]

nice inspiring video!!! thanks

[@dronefactorys6641]

Oh man very good

[@sukhee5]

Wooow i loved you Project. woow wooow. how much cost was and how how many time(hour) or minut can fly this octocopter?. When you will put the project files in the web page.

[@Mackieviczusa]

Hello. I would like to ask a question. Hiw about install the motors in a quad config? One on top of another and 4 arms? Would that be more stable? I believe cleaner looking with more space around blades and possible less issues with wind and cross wind? Please let me know your input. Great video.

[@aashutosh3721]

wow thats amazing

[@waddoo1234]

is the final product shown still out of wood or is it metal?

[@Joop_Brokking]

+waddoo1234 The version that you see in the video is made of wood.

[@bethanyhunter5884]

Lol at that freakin fly that came crawling on the screen

[@ajaykubehera]

great vd keep doing this good work..

[@paugasolina5048]

did you build the pcb by yourself?

[@theodordrymonis6728]

This is so exciting!!! Great work !!! I really hope you will continue making some tutorials that get in to details with this triple core flight controller :P . Dear santa i want some tutorials for christmas! Now i also have a "MTK3339" 10 hz gps to practice and later put it to good use!

[@ravirajurkar6106]

How much money you required to make it ??? Plz reply as soon as possible

[@guywatcho1641]

Hi Joop, Please my GPS hold is not stable, according to you what is a better way to achieve that? Can we only use Long and Lat data from GPS module? Thanks

[@crissan5035]

OMG LOL That helicopter is insane literally! OMG I laugh hard on that! Tell you what that ply wood bond with paint at some sort level cause once you paint some them wood they get hard.

[@waddoo1234]

would it be possible for you to provide a parts list, specifically the motor and battery?

[@Joop_Brokking]

0:01 motors are Cobra 2208/1200, battery is 3800mAh/20C/3S. I use 2 of them.

[@waddoo1234]

+Joop Brokking what ESC and could this still fly with a 4 motor set up do you think?

[@Joop_Brokking]

Here you can see the ESC's that I use: kzbin.info/www/bejne/kInOfJZngs2trtE With 4 motors it will not fly. One motor or ESC going AWOL is not a problem. Two will definitely lead to a crash.

[@tetradb_]

Truly inspiring! :)

[@mohamedzemour]

Hi, I want to know how to connect the RC receiver with arduino,more precisely the instruction that read the RC recever signals and then get this signals from arduino.I have another problem with engines,they doesn't start together at the same time when i connect them directly with same arm of the rc reciver(for testing perpose only),thank's for your magnificent, it's helping already, hope you answer me soon i really need help

[@Joop_Brokking]

For connecting the receiver check this video: kzbin.info/www/bejne/mHaxm59ngLaVrNE

[@mohamedzemour]

I have already seen this video and I have a hard time understanding, there is no other explanation, my problem is that the instruction interrupt reads the ppm signal, That I have to work only on her and improve myself in this see where there is other possibility? thanks in advance

[@noize007]

Hey Joop. Really impressive what you built so far :) Basically I am doing almost the same thing - building my own flight controller based on an STM32F405 microcontroller. Nex thing to me will be to implement GPS position hold. I already have some ideas how to do that, but watched some videos of other people writing their own algorithms. That´s how I found you :) And there is one question I´d mlike to ask you: Does your position hold algorithm rely on the ublox GPS only, or do you also use your inertial sensors and fuse them with the GPS? Like the spooky "double-integrating-the-accelerometer"-thing :) That´s what I intended to do and fuse data using a kalman filter. But since I saw your results I´d like to know if this is really necessary since the performance of your position hold (just judging from the videos) is really really awesome!

[@noize007]

Just saw that you already answered that question below :)

[@Joop_Brokking]

Do not go where the path may lead, go instead where there is no path and leave a trail ;-) I have learned that there are a lot of people talking about Kalman while they have no clue how it really works. They just did what others did and it worked...... sort of. When you fully understand the workings of a Kalman filter you also understand if it is necessary to use one. Don't ask me to tell you how it is done. Make your own trail and learn every step of the way. For your information: I don't use Kalman and it is working great :-)

[@noize007]

Thanks Joop. I was pretty sure that you don´t use kalman. Me neither at the moment ;) Question was, if you fuse IMU data somehow with GPS date to get that fantastic position hold, and it turns out you don´t. So maybe I start there - using GPS and baro for position hold and get that working first. If I´m finally there, I can go on and MAYBE add the accelerometer fusing to get even more stable positions (and therefore kalman - yes, I understood it ;) - is a good choice).

[@freddiesnijman]

So neat!

[@Joop_Brokking]

+Freddie Snijman Thanks!

[@WaqarRashid]

I am also planning to make my own flight controller, currently I am using Multiwii with CRIUS AIO PRO V2 board but for purposes like collision avoidance etc I really need to understand whats going on inside the controller and probably designing my own will help me great in it. I just want to ask, Where should I begin? I am already been through your YMFC videos and it helped me a lot in understanding some of multiwii code but still there is much more in it and the big picture is still not clear.

[@Joop_Brokking]

If you want to make your own flight controller you should stop using MultiWii as a reference and start building from scratch. It's a long journey but you will understand everything when you got you own quad flying. Remember that there is no "one way". There are so many ways to get a quadcopter flying.

[@kimhong7286]

i want to know, component that use to control flight action. please list me about all of component. thank dear.

[@guywatcho1641]

Hi Joop very nice Work!, please I am building my own STM32 based Octopter system, please is there any difference between LEA-6S and Neo-6M GPS modules? I discovered that they used almost the same u-block protocol. Please which Telemetry module can you advice? Thanks

[@Joop_Brokking]

The specific differences can be found in the datasheet of the GPS madule. For telemetry I use the APC220 that will give you 1200 meters of range: kzbin.info/www/bejne/inrKf3t3nKyrgJY

[@guywatcho1641]

Thanks for your reply. Please my GPS hold is not stable, according to you what is a better way to achieve that? Can we only use Long and Lat data from GPS module?

[@Randomgrogu]

On the power board with the PCB what did you put between the two to make sure they didn't act connected?

[@Joop_Brokking]

+Spandex Fool I milled back the outer edges and just glued them together. The PCB material acts a an insulator.

[@stevenlee1726]

Hello joop, how much difference is the code from quadcopter to octacopter?

[@azeembhatti7100]

Can i made a flight controler with arduino uno for quadcopter???

[@xthuan]

Have you tested the payload? I really like your copter frame, is that possible to buy one?

[@Joop_Brokking]

I mounted a 600 gram camara / gimbal and the octo performed very well. I don't sell this frame.

[@nou4898]

I Saw A Fly About 10:20 (On The Camera)

[@UCs6ktlulE5BEeb3vBBOu6DQ]

pure madness

[@evanator3165]

what type of arduino and where did you get the propellers from?

[@Joop_Brokking]

+Evanator I made the pcb myself: kzbin.info/www/bejne/b3y8nK2kdsambbM Props are Gaui 8x4.5 props (8A & 8B). I recently replaced them with Graupner 9x4.5E props.

[@Krishna1994Mr]

Awesome work sir!!! do you use the same processor to get all sensor values? I mean baro is relatively slow. how does it affect your performance?

[@Joop_Brokking]

+Krishna Srinivasan Thanks for the compliment! Yes, I use the same processor to get the data from all the sensors. The baro sensor that I use (MS5637-02BA) gives me a value every 12ms (20cm accuracy). That's more that 80 values per second that you can average. More than enough to make the octo hold it's altitude.

[@hhunoclue]

How much would it cost if I were to make this myself?

[@LordMunchable]

Hey, Im tring to make an autolevel function, im using the MPU6050. If i use the lib for it, it needs to much time for an fast control loop. Then i desided to use an complementary filter to use gyro and acc to get angle and so be able to use it for autolevel. I got into trouble because of errors if one axis get to 90°, the other axis jumped on 180° , i dont know why. The Z angle is a problem too, because i dont get it to work without an information form acc(gravity vector parallel too Z axis). And the calculation was not efficient, so it cost lot of time. My question, can you recomend a source to get information about this topic? The pages and videos i used, didnt help me. Sry for bad english :)

[@Joop_Brokking]

Don't worry about your English :-) The site that helped me a lot when I start to build my own algorithms is: www.starlino.com/imu_guide.html Hope this helps you further.

[@zacharycchen]

Amazing project..... you have inspired me to start my own flight controller. One question... How do you get the flight controller to automatically switch modes? as in the code that you use.... I'm familiar with the Arduino IDE.

[@Joop_Brokking]

What modes do you mean?

[@zacharycchen]

+Joop Brokking As in you have several flight modes such as return to home, GPS and so on..... So how do you program the flight controller to switch between the modes automatically when a certain circumstance is met?

[@Joop_Brokking]

I have a switch on my transmitter. To switch between modes you could use something like: if(switch is off){ code for normal mode } else{ code for auto level mode }

[@zacharycchen]

+Joop Brokking Oh okay, thanks. Just one more question, at 0:22, I notice you have a transceiver, I purchased the same one some time ago, and havent been able to get it working. Do you use any libraries to assist with the transciever? or is is all original? A tutorial on how you get it to communicate would be excellent.

[@Joop_Brokking]

When you get the transceivers they are already setup correctly to communicate together. Manual: www.robotshop.com/media/files/PDF/dfrobot-apc220-manual.pdf Default baud rate is 9600bps, 8 data bits and no parity and 1 stop bit. Connect one APC-220 to an Arduino and setup the serial port with: Serial begin(9600); Send data with: while(1){ Serial.println("Hello World"); delay(1000); } Connect the other APC-220 with the adapter to your computer. Open the corresponding serial port with the Arduino serial monitor and set it to 9600bps (don't chose the Arduino port!!). Now you should be able to see the text in the Arduino serial monitor.

[@kholdstare993]

Are 1200kv motors with 8x4.5'' props better than 1000kv motors with 10x4.5'' props?

[@Joop_Brokking]

The 8x4.5 props where recommended by the manufacturer of the motor.

[@kholdstare993]

Thank you for the information :)

[@Lucas-vo5ib]

Do you have schematic ??

[@pg86131314]

U are awesome subed thank u for video and knowlege

[@Sanghalhriama_Khiangte]

very interesting

[@robertoestrella3065]

Where to buy a material you used in your drone sir?

[@madaha0610]

awesome!

[@shubhamsamal2512]

I also want to know which components you used

[@Reaperaxe9]

Amazing

[@Randomgrogu]

What did you use for Auto Pilot and the GPS?

[@ansariflightplan5814]

Very nice sir... supperbbbbb job it used compass ?

[@Joop_Brokking]

Thank you. And yes it uses a compass to know in what direction it's nose is.

[@giacomopinagli4028]

Hi Joop! Very Very nice! Do you tilt compensate the compass?

[@Joop_Brokking]

Yes, otherwise the compass values are not usable.

[@giacomopinagli4028]

Thanks for your precious answer. I've tried multiple time to tilt compensate a compass (lately using also your AL imu code for pitch and roll calculations) without any luck. I've alligned accel-gyro and compass axis and calibrated the compass using magneto12 to do the sphere fitting. At this point I have the 3 magnetic field component using a matrix multiplication (3x3) and subtracting the offsets. Then used: magX = correctedMagX * cosPitch + correctedMagY * sinRoll * sinPitch + correctedMagZ* cosRoll * sinPitch; magY = correctedMagY * cosRoll - correctedMagZ * sinRoll; to find out compensated components and then atan2.. This in your lovely optic "keep in simple " :) But as soon i tilt the whole system the heading changes a lot :( So failed my mission. Do you kindly have any hints?

[@Joop_Brokking]

I used these documents: aerospace.honeywell.com/~/media/aerospace/files/technical-articles/applicationsofmagneticsensorsforlowcostcompasssystems_ta.pdf aerospace.honeywell.com/~/media/aerospace/files/technical-articles/applicationsofmagnetoresistivesensorsinnavigationsystems_ta.pdf Hope this helps