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Gini's robot blog

Hello! I am Gini and I am fascinated by all kind of robots. In my blog I will share with you what I am learning about those creatures and write about the ones I am hopefully going to build myself!

April 12, 2009 : breadboards

Over this long Easter weekend I thought it would be nice to build Guido's electronic dice: An AVR microcontroller based electronic dice .
It's a relatively easy project. All necessary information on where the pieces need to go are on the circuit board so that doing the circuit on a breadboard wasn't really necessary but still I decided to do it there first. Here you can see the picture:

Breadboards are a wonderful way to test new circuits before soldering them on the circuit board as it is much easier to correct mistakes there or try out different designs then later when everything is soldered.
Here is a picture of an empty breadboard:

You can see the two binding posts and the board with lots of holes.
Those rows with 5 holes each are connected with each other. In the picture I have circled one of those rows.
It's different with the holes in the middle (where the red and black wires go in). There 25 holes that are on one line are connected with each other. They are called distribution bus. So everything that's in one of the 25 holes that is in one line with the red wire (that is going to the binding posts) is connected with the positive end of the power source (e.g. battery, power supply). The other 25 holes are connected to the negative end of the power source.
By putting banana plugs into the binding posts you can connect the board with the 5V power supply for testing out your circuit. From the binding posts wires connect to the board (in the middle). So it is clear where positive (red) and negative (black) are.
As you can see in the first picture with the edice circuit the bigger gap is there so that microcontrollers etc. will fit in perfectly. If you want to remove those parts like microcontrollers that sit very tight in the breadboard from the board again later on you need to work very gently with a screwdriver.
Here you can see a picture of another breadboard with a simple led circuit. The banana plugs are plugged in:

January 24, 2009 : asimo robot

During the last weeks I just surfed the internet to look for interesting robots. There is so much good stuff out there! At first I had a look at the Japanese robots that are developed by big Japanese companies.

My favourite robot so far clearly is the asimo robot from honda. It's a humanoid robot and while watching several videos I was very impressed how smoothly he moved along. In fact I must admit that at first I was doubting a bit that this robot is real, that there isn't a real human inside just pretending to be a robot. Only when I saw that video where asimo crashed down the stairs was I really convinced that he is real. I'd really love to watch a presentation seeing asimo in action in reality.
He is also very light weight I think weighing just 54 kg according to honda's website.
He can run very fast, he can go stairs up and down, he can run in circles, take someone's hand and follow, he can conduct an orchestra, he can serve coffee in a special tray, wave to the audience and shake someone's hand etc.. It's really so amazing to watch.

December 14, 2008 : The three laws of Robotics by Isaac Asimov

I just came across the three laws of robotics that Issac Asimov mentions in his book "I, robot":

A robot may not injure a human being or, through inaction, allow a human being to come to harm.
A robot must obey orders given to it by human beings, except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.

I think it is desirable that robots abide to those three laws. As far as I know most of those industrial robots at work today have lots of security features to insure that there are no accidents. Of course they should obey orders given by human beings, after all this was the reason why they were built in the first place and as most advanced robots are still very expensive it is also understandable that it should protect itself as much as possible.
When I look at the robots I have built so far however I must admit that they don't abide to those laws. As they don't have any kind of real intelligence inside they simply don't know when their action would harm a human or even destroy itself. But most of them are remote controlled so it is in the hands of a human to make sure that everything is going well.

October 25, 2008 : lego dinosaur

The construction of the dinosaur is a bit more complex. But what a cute creature do you get!
To make it walk again - like with the crocodile - one motor is used which is connected with the gears to the feet. Instead of wheels the dinosaur has feet of course but otherwise it's the same mechanism.
The construction to make it open it's mouth and grawl is much more interesting now of course. The second motor controls the mouth and the arms (they move up and down). The gears are put in such a way that they let kind of a handle rotate. And with this rotation the lego bar that connects the mouth with the body goes back and forth which opens and closes the mouth. When the mouth opens widest the top part of the mouth presses the button of the sound module through its movement and so let's the dinosaur grawl.
The arms are hanging on rotating gears which let them move up and down.

October 18, 2008 : lego spider

Second I've built the spider. It also has a stable chassis and wheels on its sides (they are a bit hidden but they are there). In contrast to the crocodile however there are two motors so that each side of the spider can be controlled separately. Again the gears connect the motor with the wheels.

October 13, 2008 : lego crocodile

At the moment I am once again playing around with lego. I really like lego. It's a good way to experiment with new designs, learn about improving your design or just simply try out new things.
One lego box that I particularely like is the one that let's you build a dinosaur, a crocodile and a spider (I think it's box number 4958).
For some reason I cannot explain I like the crocodile best. So let's look at it's design: it is simple but really effective. It is a very solid chassis that can easily hold the battery case and the motor. The two gears of the motor are connected with two other gears which drive the two big front wheels. It's kind of the classic car design.
The two legs (one on each side) are mounted on the front wheels which give them their movement. In the rear the long lego bar holds them in place while allowing the moving to happen. Of course if the right leg is up front the left leg is behind and the other way round. That way it moves smoothly without jumping.
At the rear it has two other wheels that help to keep friction low.
The battery case is a bit covered to give the impression of a crocodile but still the batteries can easily be changed.
As the crocodile has no brain of its own it has a receiver so that it can be controlled via remote control. If you connected the motor strip directly with the battery it would move along more or less randomly.

October 12, 2008 : soccer robot

Now my next project was to build a soccer robot. Building it was a bit more difficult than the other one but still very doable. Only once was I running into problems: one screw was too thick and didn't fit through the hole (easy to fix) and it was also too thick for the corresponding nut. Luckily we have a collection of all kind of screws and nuts at home so I could finally find one that fit.
The soccer robot is a very nice robot. It has two motors that drive the six legs, one motor drives the three legs on each side. The feet have some kind of rubber on the bottom so they are capable to even walk on rather smooth and slippery surfaces as well as on carpets!
The robot is controlled by a control that is connected via a long cable with the robot. If you connect the motor with the control as said in the instruction you need to put one control handle forward and the other backward to make it walk forward and then the other way round for walking backwards. I found this a bit illogical and so connected it now such that if both handles are forth the robot walks forwards and if they are in the back position it walks backwards.

October 05, 2008 : robug and duck robot

Recently I put together the soda can robug (it's a kit from the 4M company). Assembling it was rather quick and easy. The instructions were easily understandable and came with a very good picture. Three holes were a bit too small for the screws and therefore needed careful widening but otherwise everything went very smoothly. The robot bug moves through vibrations and makes a rather loud sound. It's really fun to watch the robug buzzing along even though it is not running very stable and you need a *very* smooth surface otherwise it will fall over but vibrate along.

Sometime ago I've already built another robot, a robot duck. That kit also was easy to build and it is still funny to see the duck waddling along. Here the duck is walking on two feet and it's really cute!

October 03, 2008 : Talking about robots

I really really love robots, those creatures, tiny or big, funny or dull, useful or not that are built artificially by humans.
I am dreaming of a robot that can tidy my room, vacuum the carpet not only on the floor but also on a staircase, prepare delicious meals, play the games with me I want to play as long as and whenever I want to, that can fly me to school every morning so that I can stay in bed until the last minute, that can do my homework for me and knows all the answers when I have any questions for whatever topic while exploring new worlds. But despite all efforts and lots of progress so far we seem to be far off from this goal.
Reason enough to learn and explore!