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Final project assignment

Create a physically interactive system of your choice.
Please, document your work thoroughly online as you go. Include details of all phases of the project. So teachers can see your progress and evaluate your work better.  Include a project summary as well, explaining what the system you built is, what it does, and what purpose it’s intended to serve. Your summary should introduce the project.
You may work alone or in groups.

A few examples:

Musical Instruments.
Performing music involves a sustained engagement between the performer and the instrument. The feedback from the instrument has to be immediate and clear in order for the performer to continue playing. The interface has to be flexible so that the musician can exercise her creativity in playing.

Physical interfaces for gaming.
Like musical instruments, they involve constant back-and-forth interaction and immediate response.
Try to program a simple game in your computer using P5 controlled by your interface. Another idea: The game can be a physical game!

Remote control systems.
They require not only a clear interface, but must also return enough information on the remote system’s action to let you know that you’re doing the right thing. Whether it’s a remote controller for your home electrical devices or a Mars rover controller, the need for clarity and good feedback are equally essential to the person who it’s made for.

Hacking toys or games.
Find a new use to an existing toy. Expand the possibilities of a game known by all. Create new toys from existing ones. Again, very clear interaction strategy and easy to understand the behavior of the application.

Final schedule:
  • Concept presentations and questions 5 dic
  • Final plan presentations 13 dic
  • Project working demonstrations 19 dic
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The dear drawing machine is almost there..

So now the dear drawing machine is alive, watch her in action below. The darker the light the higher the resistance and thus the faster the speed of the motor. This machine is designed to be hanged on the wall to react to people passing by. If you passed by, or stand in front of it, it will start to draw according to the level of shade you project.

This is a very simple application of using a variable resistance (in this case a photoresistor (LDR)) to change voltage via PWM. Main circuit components are an Arduino UNO, LDR a 10K ohm resistor, a transistor, and a motor, and thats it. . The variable resistance is read using AnalogRead, its value is fed into the transistor base pin via PWM pins using analogWrite, and thats it for the voltage to change according to light making a difference in motor speed. Several manipulation could be done afterwards, starting from assigning different values of light resistance sensitivity to each motor, all the way to making smart moves by designing code conditions according to serial read values from serial port. As you see, the design is simple but building the machine has some mechanical challenges starting from motor alignment to adjusting all the pieces together. I had a very successful first demo (ask Alex and the group –they witnessed :) ) now I am providing better motor support and eliminating wiring connections, after that I should work on improving the code for smarter reactions.

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The dear drawing machine

So I got an obsession with this kind of machines which come in different shapes and designs. I initially planned to build a very simple analog circuit powered by a pair of AA rechargable batteries connected to SunMod solar strip, along with a resistor, an LDR, and an LP2950 voltage regulator. The idea was to change resistance with light, so when you stand infornt of the machine and block the light it starts to draw. Then Alex advised that I use Arduino for better resistance control, so I said OK :) The idea is the same but the components are slightly different, so is the protocol.
In this case, we will get the value from photoresistor using AnalogRead and feed this into the transistor’s base pin via PWM and thus change speed of motor with resistance. It is working now, however, the sensitivity of the LDR doesn’t seem to correspond nicely with the motor spin, I increased the base resistor, but more tweaking is needed and vamos a ver ! :)
//more to follow

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