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Archive for March, 2012

QuadCopters – How to get started

March 27th, 2012 141 comments

I have been watching different videos of QuadCopters recently and I’ve been pretty amused. The way they fly and the way they control their movements is unbelievable – it almost looks like a bug.

If you don’t know what a QuadCopter is, you should definitely have a look at the video below where some advanced features of cooperating Quadcopters are displayed:

So I decided to start reading some more about the materials behind these QuadCopters and how they manage to stabilize in the air.

In this blog post I will try to describe the different steps I have been thru to plan, design and build the prototype of my QuadCopter. There will be coming some more blog posts later on describing how to get the QuadCopter running, programming it, tuning it etc.

This blog post is divided into 3 parts

  1. What is a QuadCopter
    1. Brushless motors
    2. Propellers
    3. Roll, Pitch and Yaw
    4. ESC – Electronic Speed Controller
    5. Battery
    6. The frame
    7. Frame configuration
    8. Inertial Measurement Unit
    9. Controller electronics
  2. Initial decisions
    1. Theoretical calculator
  3. Conclusion

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Categories: Guides, Multirotors, TKJ Electronics Tags:

ATtinyRemote

March 20th, 2012 70 comments

I have previous thought about buying a universal remote like this one, as I was tired of grabbing my JVC remote for my stereo everytime I had to turn it on, off or turn the volume up or down. But then I discovered Ken Shirriff’s IR Library for the Arduino. Normally the library didn’t support neither the Panasonic or JVC protocol, but I discovered that somebody else had already added them. See the forked github library. At first I simple downloaded the library and tested whenever it could decode the Panasonic protocol and send commands to my JVC stereo. It had to tweak the library a bit, but then it worked just fine.
I thought it would be a bit overkill to use an Arduino and I didn’t want to rewrite the whole library, so I decided to use another AVR’s but in a much smaller package, the ATtiny85. Which is 8-pin AVR.
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Categories: Arduino, Guides, TKJ Electronics Tags:

The Balancing Robot

March 4th, 2012 599 comments

Now avaliable as a kit
A balancing robot kit is now avaliable via Kickstarter: http://www.kickstarter.com/projects/tkjelectronics/balanduino-balancing-robot-kit. Check out the blog post as well: http://blog.tkjelectronics.dk/2013/03/balanduino-balancing-robot-kit-kickstarter/.

Hello everybody
I have for a long time wanted to build a remote controllable balancing robot aka Segway – that’s was actually the main reason why I created the PS3 Bluetooth Library both for Arduino and the FEZ Devices. It has been a long time since the sneak peak and the performance has been improved a lot since then. The original one had a FEZ Rhino as the main processor, but I discovered that it was not fast enough to read the encoders, as it is not running embedded code. Also I was already using more than 10ms per loop, which I used as a fixed time loop, so I decided to step up a notch and go for a much more powerful device: the mbed microcontroller, which is an ARM Cortex-M3 running 96MHz.

It might have been possible with just a normal Arduino (NB: I have now ported the code to Arduino, see update for the code), but I didn’t want the speed of the processor to be an issue, so I decided to go for the mbed. The robot also features an Arduino Duemilanove with a USB Host Shield on top running a sketch based on my PS3 Bluetooth Library. The mbed board actually has USB Host functionality, but I decided not to port the PS3 Bluetooth Library as my original thought were to use an Arduino Due, but as you might know it hasn’t been released yet, despite the Arduino team announced, that it would be released by the end of 2011. But as soon as it is released I think I will port the code to it instead.

Video Demonstration
Here is a short video demonstration of the robot and me explaining some of the concepts of the design and how it works:
[youtube=http://www.youtube.com/watch?v=N28C_JqVhGU]
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