AeroQuad Forums

Another impressive kk-multicopter Video

Hamburg — Fri, 03 Sep 2010 12:34:18 GMT

They�re using only 3 HK401B gyros on their Boards!!

Quad ESC Design

VR4GUID — Fri, 03 Sep 2010 02:55:59 GMT

Guys,

In the past I have seen posts of people wanting to build their own Quad ESCs (one device to control four brushless motors at the same time), but I haven't run across someone that has actually done it. Can anyone tell me where I might find a design to review/consider?

Thx, VR4GUID

heading hold with gyro only

lesto — Fri, 03 Sep 2010 00:51:20 GMT

I'm trying to understand if you try and how get the absolute angle using only gyroscope.
I've take a look at the code, but c++ still a little confusing to me (it's my first time with c++)

I'm using some analogue gyro (hacked from HK401B), and I'm still trying to get absolute angle (heading hold, call it as you want ;D)
First of all:

Code:

gyroADC[axis] = analogRead(gyroChannel[axis]) - gyroZero[axis];

      gyroData[axis] = smooth(gyroADC[axis], gyroData[axis], smoothFactor);

Ok, you're reading the value and sub the zero value, but from my test seems that the zero value change over time, specially after some "shake" of the gyroscope.
I'm trying to use a dynamic zero value calculating the mid over the last 250/500 values, a great optimization of results, but I'm still working on...
I see now you have a autoZero() function, but when you call it? and I can't find findMode() (lol)

As I can understand, your smooth() is a "pass high filter":

Code:

float smooth(float currentData, float previousData, float smoothFactor) {

  return (previousData * (1.0 - smoothFactor) + (currentData * smoothFactor));

}

first of all IMHO it's a little tricky, parenthesis for the second multiplication but not for the first. better or no parenthesis on multiplication:

Code:

return (previousData * (1.0 - smoothFactor) + currentData * smoothFactor);

or to all:

Code:

return ( (previousData * (1.0 - smoothFactor)) + (currentData * smoothFactor) );

I can't understand how you get the smoothFactor, just testing?

Well writing this post have put in my mind some new ideas... For dynamic mid I can try to use a weight mid over the last X values, with a lower weight when values are away from current mid..
I want also try your smooth filter, with the last value but also with the mid of last 10/20 values
do you have any suggestion?

Mac / RealStudio / Arduino / Serial Comms

kjinx — Thu, 02 Sep 2010 23:07:42 GMT

This may be a wee bit "off topic" but for those who want to dabble in programming some type of front end app on a Mac (or PC, or Linux, RS cross compiles very nicely) which communicates with the Aeroquad sketch (or any other app where you want two way comms with the Arduino) I wrote a generalized Arduino sketch and RS program to demonstrate how to go about it. I couldn't find anything online demonstrating how to handle the serial stream with no handshaking protocol on the Mac which was very frustrating and it took me some head scratching.

RS (RealStudio) is a very nice OO programming environment which runs extremely well on the Mac and cross compiles to PC and Linux. [ www.realsoftware.com ] Disclaimer: I don't get any kick-backs I just like it.

.zip file attached

Attached Files

Two Way Communications.zip (15.8 KB)

Parts list for quadcopter...

1394 — Thu, 02 Sep 2010 20:01:13 GMT

Hello, I am looking at making a quadcopter. Below is a parts list I have made. Before I ordered everything, I just wanted to put it up here to see if I could get any feedback about the quality and compatibility of everything. Could you please post any comments or suggestions?

Sorry for the messy formatting - its copied from a spreadsheet (I have attached that if its easier to view that way) :)

ITEM | Qty | Unit Price | Sub Price

Arduino Mega 1 $64.95 $64.95 http://www.sparkfun.com/commerce/pro...oducts_id=9152
Triple axis accelerometer 1 $29.95 $29.95 http://carancho.com/AeroQuad/store/i...products_id=55
Triple axis gyro ITG 3200 1 $49.95 $49.95 http://carancho.com/AeroQuad/store/i...products_id=54
AeroQuad shield v2.0 1 $29.95 $29.95 http://carancho.com/AeroQuad/store/i...lq96ubnt2neut0
Stackable female headers 1 $4.95 $4.95 http://carancho.com/AeroQuad/store/i...products_id=13
Breakout pins 2 $2.50 $5.00 http://carancho.com/AeroQuad/store/i...products_id=14
BP A2217-9 Brushless Outrunner Motor 4 $20.00 $80.00 http://carancho.com/AeroQuad/store/i...73gml2uhmu2m92
PhiFUN I2C 18 AMP ESC (4 Different) 4 $37.95 $151.80 http://carancho.com/AeroQuad/store/i...products_id=67
ZIPPY Flightmax 4400mAh 3S1P 15C 2 $26.79 $53.58 http://hobbycity.com/hobbycity/store...idproduct=6504
APC 10x4.7 Slow Flyer Propellers 4 $2.93 $11.72 http://www.apcprop.com/ProductDetail...ctCode=LP10047
APC 10x4.7 Slow Flyer Pusher Propellers 4 $ 4.39$ 17.56 http://www.apcprop.com/ProductDetail...ctCode=LP10047
DX7 7-Chan. Air Tran. Only MD2 by Spektrum 1 $ 229.99 $ 229.99 http://www.toddsmodels.com/SPMR7700_...p/spmr7700.htm
DSM2 AR6200 6-Channel Receiver Ultralite 1 $ 79.99 $ 79.99 http://www.toddsmodels.com/SPMAR6200.../spmar6200.htm
Turnigy Accucel-6 50W 6A Balancer/Charger w/ accessories 1 $ 22.99 $ 22.99 http://hobbycity.com/hobbycity/store...idproduct=7028
12V 5A 110/240V 50/60Hz Power Supply 1 $ 9.99 $ 9.99 http://hobbycity.com/hobbycity/store...idProduct=6256
Battery Alarm 1 $ 3.99 $ 3.99 http://hobbycity.com/hobbycity/store...idproduct=7223
Rhino 610mAh 2S 7.4v 20C Lipoly Pack 1 $ 3.92 $ 3.92 http://hobbycity.com/hobbycity/store...idproduct=7305
Receiver Cables 1 $ 9.95 $ 9.95 http://carancho.com/AeroQuad/store/i...products_id=25

Wireless Camera 1 $ 81.71 $ 81.71 http://www.sunsky-online.com/view/13...ransmitter.htm
Tail Boom 1 $ 12.99 $ 12.99 http://www.rcplanet.com/Align_Tail_B.../agnhn6031.htm .

Motors and escs for quadcopters <2 kg ~ 4.4 lbs
TOTAL 35 $ 954.93

Thanks,

Aedhan

Attached Files

QuadCopter Materials.pdf (55.3 KB)

I2c?

1394 — Thu, 02 Sep 2010 19:30:36 GMT

Hello, I am new to QuadCopters, but not as new to electronics and programing. I have been looking around this site and have come across the I2C communication protocol. Not knowing what it is, I looked it up on Wikipedia, only to find a very broad description with nothing specifically discussing ESCs, etc...

I also am considering buying the new I2C ESCs from the store as there is only one BESC left in stock, and none left at hobbyking. While they are more expensive, they are in stock and I assume there is something better about them?

Could someone please explain what I2C is and how it is useful to Quadcopters?

Thanks,

Aedhan

Questions about V2.0 Shield for Arduino MEGA

1394 — Thu, 02 Sep 2010 19:16:44 GMT

Hello, I am kind of new to QuadCopters. I was looking at buying the new 2.0 shield for the Arduino MEGA, but before I do I have a few questions.

I see that only the Gyro (ITG 3200) is required to fly a QuadCopter and assume it will work with the latest software release. Is this correct?

I was going to start with buying the Gryo breakout board and the Accelerometer breakout board. Will this give me reliable and stable flight?

I also saw that a few other sensors/ peripherals will be written into the code in the near future (12.2010) I understand the extent of use of some i.e. the barometer is used to determine altitude - not a whole lot more, etc... but I was wondering to what extent the GPS will be used in the future software releases? location logging? altitude determination? or full autopilot?

I would be most interested in full autopilot and would love to use the AeroQuad platform to do this, since I like the platform and the accessibility of the website and store... lots of great information and a great place to start. I also like how it is arduino based.

As i build my QuadCopter i plan to document the build and post it to this site as a resource to others.

Thanks in advance

Aedhan

Yooo..Gonna build a copter!!

Electronicsdevil — Thu, 02 Sep 2010 18:54:44 GMT

Since last may I have been searching for good information and I found this forum(actually I found it in first attempt only). I have finally decided to build my own copter.

Can anyone tell me flow according to which I will have to proceed. Shipping price is too high from abroad to India and hence I can not buy it from your store,is there any alternatives available? I am fairly new to RC world, though I know much about things but no communication part as yet and want to get introduced step by step.

If you suggest some books, websites through which I will get more help, then I will be very thankful to you guys. I am really fascinated. I think excitation is making my thread more and more lengthy. Hope you understand what i need.

Shortlist: (I am a fast learner so please help)

Introduction to RC world.
Step by step involvement into RC Aeroquad.
Alternative parts (Especially adruino board as I don't know much about it, help would be appreciated) :)
Some guidance in the future.

Need Help

alexprata — Thu, 02 Sep 2010 17:52:05 GMT

Im using the the combo IDG500 gyro and ADXL335 accelerometer with IZX500 and Im not geting response with the configurator, Im using a custom shield similar to shield1.7.
Any sugestions?
And i have another doubt about motors, wich they have run on clokwise and counterclockwise, and wich I have to put propeller pusher?
Im not found this os forum so hope there is someone can help me.
thanks.

Angle compensation SHARP IR

Honk — Thu, 02 Sep 2010 03:21:59 GMT

Tonight I realized my 4th big frame was too weak too handle the motor vibrations so I continued work on my small toy quad instead. It has a SHARP IR sensor on it (1.5m range, the one they used on the Ardu IMU quad around it).

Difference is that I didn't buy 4, I have one mounted under it for altitude hold/regulation. After having played around with them for a while I noticed they give a REALLY good measure of absolute distance whatever angle to the object they measure to supposed that object is fairly rough to reflect light in a 180 degree arc. Such materials are my walls and my floor fortunately.

Then I thought: if I was to hold altitude from that, the quad would move around like if it was tied to a stick put on the ground, like in an arc.

Tonight it came to my mind that since we have very accurate relative-to-calibrated horizon angles. The good flightAngle variable accessible for both roll and pitch can then be used to compensate for this virtual arc by simple trigonometry. I did this with the SHARP IR sensor and got extremely good results! I could tilt the quad around to whatever angles I wanted compared to ground and it would still read the same distance to ground if I held it at the same height, which is exactly what I wanted.

I think this can be effectively used to compensate for angles to walls too if having them mounted viewing horizontally, which would give more accurate readings although maybe not as crucial for obstacle avoidance.

The code is quite simple (reading the sensor and getting centimeters and filtering first):

Code:

float readFilteredSHARP () {

  proxSens = analogRead(PROXSENSPIN);  

  

  voltage = (float)proxSens * VOLTS_PER_UNIT; // ("proxSens" is from analog read)

  inches = 23.897 * pow(voltage,-1.1907); //calc inches using "power" trend line from Excel

  rawDist = 60.495 * pow(voltage,-1.1904);     // same in cm

  if (voltage < .2) inches = -1.0;        // out of range

 

  rawDist = constrain(rawDist, 20, 150); //cm

  

  filteredDist += ((rawDist - filteredDist) / SHARPFILTERGAIN);    //gain = 2, super IIR filter

 

  return (filteredDist);  //cm

}



compDist = ( ( (cos (radians(flightAngle[ROLL]))) + (cos (radians(flightAngle[PITCH]))) )  / 2 ) * filteredDist;

If only the small quad I have wouldn't have a bad motor I think this would be a very good regulation value.

Good night!

No Counter rotating props.... Anyone tried this?

joshuahynes — Wed, 01 Sep 2010 18:45:29 GMT

It occurs to me that if I put in an offset angle on the #1 and #3 motors, I should in theory be able to drive them in the same rotation as #2 and #4. Tricopters all run CCW and they compensate for yaw by vectoring thrust on one (tail) boom. If #1 and #3 have a built in thrust vector, then speeding them up should cause yaw in the direction of the thrust offset, so the software would work the same.

Thoughts?

Yes, I am this irritated by difficult to get counter-rotating props.

I2C ESC advantage over PWM

Kenny9999 — Wed, 01 Sep 2010 14:43:13 GMT

Don't know if I'm in the right section... so, feel free to move it in that case!

Just see that there is some I2C ESC in the store and they are kind of expensive. Just wondering what is the benefit/advantage of the I2C ESC? otherwise of the pin availability?

Aux channel not responding?

cheongkitweng — Wed, 01 Sep 2010 07:55:52 GMT

Hi,
While doing the transmitter calibration all the other channels show movement except the Aux.
What could be the problem?
I am using the DX 6i, AR6200
Ardunio Duemilanove
Flight software V 1.7

Tedrocopter vs. Geese

Tedro — Wed, 01 Sep 2010 00:37:15 GMT

I didn't realize ganders would hate so bad on the Tedrocopter. I guess they saw it as a more dominate flying bird that could possibly steal their geese and eat all their grass. I'll have to try again in better lighting...

Round 2

Flips - how do I configure PID settings?

Tedro — Tue, 31 Aug 2010 23:19:38 GMT

Now that I'm getting better at flying... I want to soon attempt flips, but how are you pros setting up the PID values to do nice flips?