Self balancing robot


It’s really been a very long time since I added this on my todo list, and in the past couple of week-ends I finally found the time to do it.

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Stepper motor bluetooth serial driver


First Test using an Arduino (clone) board

First Test using an Arduino (clone) board

Above is the image of my very first attempt of driving this nice little bi-polar stepper motor (M35SP-11HPK) that I had salvaged from a broken Canon printer a while ago.

I have quickly put together a L293D H-bridge with an Arduino board and using the Stepper library was quite straight forward

For the impatient you can see a (probably boring) video right after the break…

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Quadcopter – home made


29 Mar 2011 – V2 is here !

Latest and greatest version, not that light but not too heavy either...

Quadcopter V2

Now I know it was all useless, but until 2 days ago, I still thought the only problem with my quad was the frame/motors and the huge vibrations they generated…

2 days ago, on Sunday night, I finally had the courage to face the truth : it could be my fault, it could be my code ! 🙂

Actually while looking at the http://www.multiwii.com/ site (huge thanks Alexandre, and really great stuff !!!) it occurred to me that their code should support my configuration out of the box.

To be honest, I’ve always though that it might be a problem with my code, but the only options to check this would have been:

  1. buy an ardupilot or some other verified system and install it
  2. modify the ardupilot or some other verified code to make it run on my configuration

None of the above options were easy and they could have introduced new problems by themselves…

But the multiwii code, looked like it should work with barely a few lines of change !!!

And indeed it WORKS ! Or at least it balances muuuuch more steadily on 1 axis !

This seems to prove that while I do have quite a lot of vibrations they don’t stop the quad from flying.

I still don’t know what the exact problem was with my code, I will have a look into the details once I manage to fly for real with the new code…

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Motor vibrations


No motors running, just "natural" noise of the sensors...

This post is obviously related to my “roman-fleuve” post about my attempt at building a quadcopter… I’ve decided however to create a new post as the initial one has already become too long, and dealing with vibrations is a more general mechanical question, that applies to much more than just quadcopters.

I still don’t know why my quadcopter refuses to balance properly, and to be honest it could be anything: the frame, the motors, the ESCs, the code, literally ANYTHING !

However, I have the feeling it’s related to vibrations, and there’s only one way to find out: done with the funny part of building the quad, now enters the tedious/annoying task of setting a vibrations test bench and do some measurements…

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