HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Nov 29, 2008, 06:02 AM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,526 Posts
Great info! All these tests are being done with EPP1045's that have been balanced I presume? There is enough varibility in prop balance to skew the results.
Cheers,
Jim
jesolins is offline Find More Posts by jesolins
Last edited by jesolins; Nov 29, 2008 at 10:03 AM.
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 29, 2008, 09:12 AM
Registered User
brashley's Avatar
Joined Dec 2006
517 Posts
Funny, I use am Mdrive for my motor testing as well. I like the serial PC control and the RPM readout you get. I love the thing, I have a couple of them in my park flyers as well. I have done a fair amount of motor testing with it on my little setup. It would be great to give this one a try once it is done and compare the results. Your data is looking good...

It will be interesting to see the impact the breaking will have of the MK control and flight characteristics. I bet we will have to retune the MK PID control to get maximum benefit out of it (beyond just efficiency gains)

Richard
brashley is offline Find More Posts by brashley
Last edited by brashley; Nov 29, 2008 at 09:24 AM.
Reply With Quote
Old Nov 29, 2008, 10:08 AM
13brv3's Avatar
Navarre, FL
Joined Mar 2002
3,839 Posts
Quote:
Originally Posted by brashley
Funny, I use am Mdrive for my motor testing as well. I like the serial PC control and the RPM readout you get. I love the thing, I have a couple of them in my park flyers as well.
I had never even heard of the Mdrive, but it sure looks like a nifty little ESC. It's a real shame they don't include I2C interface capability. I may send them an email and ask if they've considered adding that capability.

Cheers,
Rusty (elaborate Rev2 test rig nearly ready for use)
13brv3 is offline Find More Posts by 13brv3
Site Sponsor
Reply With Quote
Old Nov 29, 2008, 11:49 AM
Registered User
Meopham, Kent UK
Joined Jul 2008
136 Posts
Quote:
Originally Posted by jesolins
Great info! All these tests are being done with EPP1045's that have been balanced I presume? There is enough varibility in prop balance to skew the results.
Cheers,
Jim
Yes props fairly balanced - same specimen used for both controller tests.
I recall the Mdrive was a little slow dynamically driven by PPM signal for quadrotor flight use, but yes a nice product.

Richard - I agree the PID loops will likely need retuning, probably the differential terms will be most affected. We use our own design of flight computer, and will learn in due course to give some pointers.

Will update when we have some new data.

So if everybody prefers a standard format controller is the LED function still of interest? the options are open collector ports 3 or 4 off - the user sets the current limit externally with a resistor. We provide simply I2C addressable switches, pwm'd to achieve a brightness or flashing.

We also have 1A 5V switching regulator on board. Is that totally necessary - currently used for LED's?

Steve
airbotix is offline Find More Posts by airbotix
Reply With Quote
Old Nov 29, 2008, 11:56 AM
13brv3's Avatar
Navarre, FL
Joined Mar 2002
3,839 Posts
Hi Steve,

My vote would be no LED's, and no 5V supply.

Thanks,
Rusty
13brv3 is offline Find More Posts by 13brv3
Site Sponsor
Reply With Quote
Old Nov 29, 2008, 04:27 PM
Registered User
brashley's Avatar
Joined Dec 2006
517 Posts
I would agree with Rusty (especially if it keeps the price down)

Richard
brashley is offline Find More Posts by brashley
Reply With Quote
Old Nov 29, 2008, 05:52 PM
Registered User
Sydney, Australia
Joined Jul 2008
35 Posts
Me too!
keeping it small, lower cost, simple pcb layout is the way to go.

max
Maxrr is offline Find More Posts by Maxrr
Reply With Quote
Old Nov 29, 2008, 05:56 PM
Tri-Quad-Hexa-Octo-copters!!
United States, TX, San Antonio
Joined Feb 2007
14,526 Posts
I agree. Keep the ESC minimum and robust. There are plenty of LED options out there and they are simple to do if you want to.
Cheers,
Jim
Quote:
Originally Posted by Maxrr
Me too!
keeping it small, lower cost, simple pcb layout is the way to go.
max
jesolins is offline Find More Posts by jesolins
Reply With Quote
Old Dec 05, 2008, 07:56 PM
Registered User
Fredjikrang's Avatar
Joined Oct 2008
330 Posts
Any news on this?
Fredjikrang is offline Find More Posts by Fredjikrang
Reply With Quote
Old Dec 05, 2008, 08:21 PM
Registered User
Meopham, Kent UK
Joined Jul 2008
136 Posts
Quote:
Originally Posted by Fredjikrang
Any news on this?
Sorry nothing else to say at moment, but working hard on it!

Steve
airbotix is offline Find More Posts by airbotix
Reply With Quote
Old Jan 31, 2009, 09:06 PM
Registered User
brashley's Avatar
Joined Dec 2006
517 Posts
How is it going???? Any progress....
brashley is offline Find More Posts by brashley
Reply With Quote
Old May 16, 2009, 03:29 PM
Registered User
Canada, ON, Toronto
Joined Jan 2008
455 Posts
any word
Looks like a great project, but looks like it went over the cliff ---- crash!

hope not, had great possibilities
dowlinger is offline Find More Posts by dowlinger
Reply With Quote
Old May 18, 2009, 11:42 AM
Registered User
Meopham, Kent UK
Joined Jul 2008
136 Posts
Sorry for a long awaited update.
We have woking samples but I am afraid it will have to stay at that for the moment. Basically we are too busy on our micro quadrotor development, and the payback for doing motor controllers requires high volume to keep the pricing appropriate.

During development of the motor controller we have found I2C is not totally reliable - partly due to our chosen processor. We prefer, and have implemented a simple PWM command method still giving 1kHz update rate.
A 1kHz PWM control signal effectively commands thrust proportional to pulsewidth. In this way no I2C interface latch-ups can occur.

We will of course make it known if the position changes.

Steve
airbotix is offline Find More Posts by airbotix
Reply With Quote
Old May 18, 2009, 05:11 PM
Registered User
Canada, ON, Toronto
Joined Jan 2008
455 Posts
Could you expand on the issie with I2c and your chasen processor.
Maybe some of us could help resolve your issue.
I am sure we would be interested in your finding at the least
Thanks in advance
Paul

Quote:
Originally Posted by airbotix
Sorry for a long awaited update.
We have woking samples but I am afraid it will have to stay at that for the moment. Basically we are too busy on our micro quadrotor development, and the payback for doing motor controllers requires high volume to keep the pricing appropriate.

During development of the motor controller we have found I2C is not totally reliable - partly due to our chosen processor. We prefer, and have implemented a simple PWM command method still giving 1kHz update rate.
A 1kHz PWM control signal effectively commands thrust proportional to pulsewidth. In this way no I2C interface latch-ups can occur.

We will of course make it known if the position changes.

Steve
dowlinger is offline Find More Posts by dowlinger
Reply With Quote
Old May 19, 2009, 02:31 PM
Registered User
Meopham, Kent UK
Joined Jul 2008
136 Posts
Paul

The processor we used was Luminary Micro LM3S811 - a fairly good and flexible processor but it seems some weakness in I2C. The issue is an infrequent I2C bus hang - likely due to noise, slave wont realease back to master. Some software can sort of correct issue, but to be honest I2C is a bit pony. Common earth for I2C and power doesn't help. It probably doesn't have a schmitt trigger front end.

The PWM sensing solution is totally robust but non-standard to requirements.
Today we use that solution to good effect.

Steve
airbotix is offline Find More Posts by airbotix
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Jeti brushless controller... HELP!!! Dan Chase Power Systems 6 Oct 14, 2003 11:16 AM
Jeti 70 amp brushless controller on 18 cells-- no problem Andreas Power Systems 12 Sep 25, 2001 09:58 AM
Aveox L160 Brushless Controller Steven Horney Aircraft - Electric - Airplanes (FS/W) 4 Sep 17, 2001 06:13 PM
pic based brushless controller fisher Power Systems 1 May 28, 2001 10:39 AM
Kontronik Brushless controller modes (3 or 4)? ShakyHands Electric Heli Talk 0 May 25, 2001 07:40 PM