Developer

ArduIMU Quadcopter part II (mini)

Hi all,
I have finished my second quadcopter with ArduIMU. This time is a "mini" version with only 28cm from rotor to rotor and has the new Jordi´s magnetometer integrated!.
This tiny machine is fantastic, with a great stability. Look at the hands-off part of the video inside house!!
Very funny :-) Video:


Specs:
Motors: 1811 2000Kv 10grams brushless motors
Props: standard 5x3
ESCs : Turnigy 6A
Batt : 2S610 Lipo
Weight (RTF) : 180grams
Again it´s a very cheap and easy setup. Because I use standard propellers I mounted left and right motors with some twist. I´d really love arduIMU flat hardware...


Look at the PPM output Rx, Is this a new 2.4Ghz receiver form DIYDrones?
No, it´s a "lighweight" (4.1grams) mix between Spektrum AR6110 Rx and Jordi´s PPM encoder. This is nice for DIY projects...


The code is improved from the old version. This one has the magnetometer integrated so now we don´t have drift
on yaw axis, better implementation for the D term on the PID controler (more responsive to user inputs), same safety improvements, fast ESCs update rate (166Hz), new PID tunning...

But this history had an interesting lesson for me... The prototype you see here are really the second one, the first one was a dissaster... (flys bad...)
Do you want to know the "small" difference between them? This:


For the first one, I use an U shaped aluminium arms to save some weight. Well this shape is very bad in torsion and generates a lot of vibrations. This vibrations saturate the gyros (our gyros are quite sensible on vibrations because the low internal resonant frecuency). You could see here a graph of the gyro output value vs Throttle and you can see clearly the effect...


I change the arms to the square shape (8x8mm) and problem gone!! Perfect stability... :-) Vibrations are our enemy (Lesson learned)

Here is the new source code: Quad1_mini_20.zip (see notes.txt inside)
Schematic (conections): Photo1 Photo2
Old post (first version) here

New ArduPilot Mega will be a perfect platform for Quad´s also, so stay tuned...

Jose.

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Comments

  • Can confirm, just made a 300mm quad with aluminium profiles, welded in the middle. Arms tend to twist generating terrible twitches in flight. Gonna try with square profile next.

  • Hello Jose,

    We are trying to create a quadrotor.

    We use your code and we have the same problem with Yun Youngiun. The quadcopter keeps on turning on one side for no reason. Each time different side. What can we do to fix it? Is there a possibility that vibrations cause this? we tried calibrating the gyros acording to your notes but still nothing happened.

  • why my rx value from 8ch ppm encoder not Correct. I use receiver futaba r617fs .I connect receiver to 8 ch ppm encoder v.2 and board arduimu v2 follow instructions. I Measure the signal output of the 8 ch ppm encoder is shown picture

    3692247503?profile=original

    the signal output of the 8 ch ppm encoder

    3692247516?profile=original

     

    please help me

  • HI, Jose

    My team and I are building a Quad rotor and i hope i can get some help from you, all of us are newbies and know nothing about building a drone

  • hi, Jose,,

    i really-really interested with your Quadcopter..

    i already buy the ArduIMU but i cant upload the program

    can you help me?

    thank you very much

  • CAN YOU HELP ME OUT with the connections of PPM encoder to ARDUIMU?
  • Hi, I'm doing a ArduIMU quadcopter with V2. Cargo Arduimu code without problems and HappyKillmore ArduimuTest is fine, but when I try the plate with a servo and transmitter receiver does nothing, no move to move the plate, and even when I move the levers on the transmitter. I tried to verions 1.5 - 1.6 - 1.7  - 1.81 and 1.8.2.
    At first I did not use GPS or barometric or magnetometers.
    Can anyone help?
    I use a Tx JR 388 (35 Mhz) and Rx NER589X (PPM). No works directly and no work with PPM encoder.

    Thank you for your attention.

  • hello all
    i have read all your post on the forum.
    i am building a quadrotor same like here.

    Currently i have arduimu+v2 board with Magnetometer attached.

    And i have 8 chaneel ppm encoder from diydrones store.

    i am using Spektrum DX5e Radio With AR500 5 channel receiver.

    i have programmed the imu with the Quad_mini20 firmware with
    some parameter change.

    I have connected the receiver channel to ppm encoder in
    following order:

    Receiver PPM Encoder
    Aileron CH1
    Elevator CH2
    Throttle CH3
    Rudder CH4

    But in the serial monitor i am getting following values:
    JJ ArduIMU Quadcopter 1.20 mini PID
    Rx values: 1037,1037,1037,1037
    ,0
    ,0
    AN[0]:381.11
    AN[1]:391.98
    AN[2]:365.85
    AN[3]:506.50
    AN[4]:512.00
    AN[5]:510.00
    -2,4,0,0.00,20
    -5,7,0,0.00,14
    -8,9,0,0.00,14
    -12,10,-1,0.00,14
    -15,11,-2,0.00,14
    -17,14,-3,0.00,14
    -20,16,-4,0.00,14
    -22,18,-4,0.00,14
    -24,20,-13,0.00,14
    -25,21,-22,0.00,14
    -24,21,-31,0.00,14
    -22,19,-40,0.00,14
    -18,17,-48,0.00,14
    -13,14,-57,0.00,14
    -10,12,-65,0.00,14
  • my ArduIMU v2 quad

    http://www.vimeo.com/19047137

  • Awesome pics and a good info hope to see more
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