phys com

homeworks for wednesday physical computing class

Atmospheric sound lamps

For the final project for pcomp class I wanted to do something with light and sound, so I partnered with Yining Shi ( I liked her idea of having singing lamps.

After the brain storm we wanted to make 7 lamps each with a scale note that would light up with touch, and also if you sing the right frequency of the note.  But, after the first feedback in class, we concluded that it was going to be confuse for the user to interact with them, so we decided to stay with the touching interaction.

The lamps we made were newspaper and homemade glue (flour and water) over balloons.

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The lamps where cover in the inside with aluminum paper that would act us our capacitive sensor for the input in the arduino program. For the sound we learned how to use Maxmsp.

After the second feedback in class and because of the size of the lamps, we decided to reduce the number from 7 to 3, and instead of musical notes they would play space atmospheric sounds.  For the installation we used a cloth rack where the 3 lamps could fit in a nice way and also solder the circuit more organized.

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Here’s a video with the final presentation in class:


We still gonna work with the sound velocity reaction, and also put some capacitors of 470pF in between sensor pin and ground.


Pcomp final process blogging 1.0

For my final project me and Yining Shi ( are going to make and installation with music and lights.

The installation consist in 7 lamps ( music notes C D E F G A B ), that turn on and play a note when the user touch them. We also wanted to have another input through a microphone, so when somebody pitch the right note one of the lamps will turn on depending on the pitch of the voice.


Here’s the video of a circuit that turns on LED and plays a tone using the capacitance library in arduino.

After presenting the project to our classmates and doing some software research  we ended with the following conclusions:

1- The two inputs (touching and singing) may confuse the user understanding the installation.

2- Some users don’t like to sing in public no matter what the cause is for.

3- We need a provocative design for the lights so the users know he/she has to touch them to interact with them.

4- Max MSP is a friendly software to use when your using sound, so our tones will be controlled by this software.

5- LED are not bright enough, and working with 120V could be risky, so we will work with 12V lamps, and control them with arduino.


Using transistors and arduino labs

This is a nice lab to control higher voltage circuits with arduino,,

what you have notice is that the transistor pins in the schematic design are mistaken the 2 and 3, so is better if you follow the picture of the circuit,,

herephoto (5)


For the second lab, we learn to use and  Hbridge so we can control the movement direction of the DC motor, heres a video how it works:



Singing Family

The following video explains the process of the project:


Inspired in “Peter and the wolf” where each character has his own instrument, we made one for each family member, in this case father is the bass, mother organ and the baby indian citar.  For which we create a small piece in logic, thinking in the harmony in between characters so when they sing all together it would be a nice song.

The main problem we had with this project was the order to make it. At first we programmed all in processing using keys and the mouse simulating the switches and force sensor. So when we tried to use the serial communication we had a bunch of errors and it was really hard for debugging.

So we begin with 2 rectangles (main figures of our animation), and from then start adding the rest of the program.

Here’s the arduino code =  arduino_dude.ino

Here’s the processing code  = class.pde serial_communication.pde sing.pde


labs for class 5

In this two labs we could see processing software interact with the Arduino chip.


Here are the values of the potentiometer displayed on CoolTerm software (be sure to close the monitor in arduino)

coolterm reading data

Then we use serial library in processing and add the port name to the code between “”

processing y arduino

Finally we have the picture of the program showing the increase of the potentiometer.

line draw with potentiometer


Here we use an accelerometer and a switch as the inputs for the arduino (2 analog and one digital ).


By the following picture we can see the program and the monitor screen, where we’re receiving the 3 sensors info, accelerometer x and y , and the switch status (0 = OFF, 1 = ON)

Be sure to check the range of the accelerometer you use, so then you can map the x and y position with the correct range.

3 sensores

When adding the program in processing, if a variable is declare in a ïf” statement, be sure that when the variable is used (as in the for loop) is inserted inside the {} of the ïf”statement.

The program run ok, only sometimes i had the following error, that was solve if I save the code and run it again.error

After the punctuation method we did the Hand n’shake where you have to pay attention that some variable  (sensor names) are not the same as the program you already have so just do the little changes.

In the next picture you can see that arduino stops writing “hello” after receiving a signal.

hand shake arduino

Here is the link to the ball controlled with the circuit (I decide to increase the size of the ball)


Interactive technology

The objects I picked to see how they work was 2 ovens, a toaster oven and a regular cook oven,, both with digital controls to set the users desires settings.

The toaster oven is the toaster located in itp close to the administration offices. The one time i tried to toast my bread there i thought it took way to long to do it, if you put the toast function on the display, it says that the duration is about 4 minutes, a regular toaster does that in less than a minute. Also when you put start, you can see that the time is no running, it takes a moment to do it, so you start thinking somethings wrong. I ask some staff to help me with it, and they couldn’t explain how to make it work,, at the end i just picked my bread even tough it wasn’t toasted as i wanted.


Contrary the other toast oven next to the microwave, where you only have a timer knob and a type of heating knob, its really easy to use it, and it fulfills its purpose in a no complicated way.

toaste easy

Other oven i use only less than half of the function it has is the oven where i live. The main problem i find in this machine is that you can’t heat up or lower the temperature once it’s set. Also when you wanna bake, it starts at 350 (does not specifies celsius or Fahrenheit degrees) and to lower the temperature, it goes down 5 degrees at the time at a constant speed without increasing the speed of this the longer the button is pressed. The other person that lives with me, stopped using it long time ago, telling me that he always have trouble with it.


I think my birthday cake won’t be baked at my place

labs for class 4


For this lab the first, we choose a force sensor to control de servo motor and the first thing we did was to check the range of the sensor that was from 0 to 1004.
Screen Shot 2014-09-21 at 15.42.44

After mapping the range from the sensor to degrees (0-90 one movement 90 – 180 opposite) we connect the rest of the elements and make the servo motor work.

A) After connecting the circuit as said on the lab page, you can tell that the minimum value of the range was obtained only when one photocell was cover, and the maximum value of the range was obtained when the other photocell was cover,, if you cover or uncover both, you obtained a medium value. High value means higher frequency tone, and low value means low frequency tone.

B) A melody was coded so when the circuit was powered it could play it.

C) At last a “three note keyboard” was built with force sensors as it is shown in the following video:

What is interaction??

I believe that interaction, as said on Chris Crawford book The Art of Interactive Design, is something that we had experience it since we were born. In different quantities of interactivity, for example, I think that interactivity between persons (depending on the action) it the biggest experience you could get, instead of a person between animals and objects. By that I believe that interactivity is a sequence of actions between two objects (people, animal, computers) in which each one reacts to the other action, in a logical way, depending on the emotion and reasoning that this object feels at that moment.

Base on my interaction definition, I really agree with Bret Victor point of view on his article, “A Brief Rant on the Future of Interaction Design”, where in conclusion he hopes that our vision of the future won’t be like in the video, as he says “a timid increment from the status quo“ in which all you can see is people using tablets, and more advanced computer in they daily life, which probably are used to handle real modern machines, but that is not shown on the video. I would like to see real technology for example new solar cells that could give energy to a whole city with only one day of sun exposure.