DanielAndrade.net http://www.danielandrade.net Daniel Andrade Tech Stuff Thu, 26 Aug 2010 15:42:32 +0000 en hourly 1 http://wordpress.org/?v=3.0.1 My moodlamp project http://www.danielandrade.net/2010/08/19/my-moodlamp-project/ http://www.danielandrade.net/2010/08/19/my-moodlamp-project/#comments Thu, 19 Aug 2010 02:50:24 +0000 DanielAndrade http://www.danielandrade.net/?p=344 This is a project I have for quite a long time, since before I knew how to use microcontrollers. Now I may study chromotherapy to apply the lamp for this techniques. For now I have it on my room, that I use to relax and it works!

What do you think? ;)

]]> http://www.danielandrade.net/2010/08/19/my-moodlamp-project/feed/ 0 Working with LEDs and Resistors http://www.danielandrade.net/2010/03/13/working-with-leds-and-resistors/ http://www.danielandrade.net/2010/03/13/working-with-leds-and-resistors/#comments Sat, 13 Mar 2010 14:56:57 +0000 DanielAndrade http://www.danielandrade.net/2010/03/13/working-with-leds-and-resistors/ The objective of this text is to help you to understand how Resistors work and use it in it’s most simple use, as a current limiter. If you want to know more about resistors and leds, check Here and Here.

RESISTORS:

The resistor is a passive component that is opposed to the electrical current dissipating heat, the higher the resistor value, the lower the current. This effect is called electrical resistance, while the component resistor is popularly known as resistance.

Resistance: is the property of a material to oppose the flow of electric current and dissipate power. Unit: Ω (Ohm).

Resistor: A component specifically designed to have resistance.

Utilities of resistors:

  • Limiting the current that flows in a circuit
  • Control the loading speed of a capacitor.
  • To make current and voltage dividers.
  • Transforming energy into heat (Joule effect).

When applying a voltage in a resistor, it creates a current that passes through it. The relation between the voltage and the current defines the electrical resistance:

It’s a physical law and, therefore, will always work for any type of electronic circuit.

If the Voltage is directly proportional to I (R = constant), we have the famous OHM’s law.

Most of the resistors used in electronic obey this law, ohmic resistors. Among them are the cluster of carbon resistors, metal film and carbon film.

Practicing – Leds and resistors

To light up a LED we need to limit the current that flows through it, for that we use resistors. If the current that flows through it is higher than recommended, there is a high risk of burning the component.

The video below show’s a led being burned:

Video Soon

The recommended current and voltage between the terminals of the LED depends on the chosen type (color, diameter, shape, etc.). For more details, take a look on the datasheet.

The higher the current, higher will be the light intensity and lower the LED’s life.

Building the circuit:

To light a LED we need:

  • 1 Led
  • 1 Resistor (ohmic)
  • Power Supply (here we will use 5V and 12V)

So which resistor to use?

Now we are going to see which resistor to use, using the Kirchoff`s Circuit Laws.
They are physical laws, will always be valid for any circuit.

We will use a red LED, when that should work with around 1.7V.
The recommended current for an LED is between 10 mA and 20 mA.
Here we will make the math to use only 10mA.

Using a 5V power supply, we have by Kirchhoff’s Voltage Law


With this, we show that you only can insert the resistor after of before the LED.

By Ohm`s Law:

Now calculating the resistor for 10mA:

By OHM’s law:

Due to the associated error with each resistor and the available values on the market
we will take approximate values.

In this case we do not make approximations of the resistor value
because it’s commercially available.

For a voltage of 12V, R = 1 030 Ω, then we will use 1KΩ.

This article was written by Lucas G. Carli ( lucasgcarli [a] gmail dot com ) – Undergraduate in Electric Engineering

]]> http://www.danielandrade.net/2010/03/13/working-with-leds-and-resistors/feed/ 1 Speeding Up a DC Engine with Magnets http://www.danielandrade.net/2010/03/13/speeding-up-a-dc-engine-with-magnets/ http://www.danielandrade.net/2010/03/13/speeding-up-a-dc-engine-with-magnets/#comments Sat, 13 Mar 2010 14:33:06 +0000 DanielAndrade http://www.danielandrade.net/2010/03/13/speeding-up-a-dc-engine-with-magnets/ Electromagnetism is fun!

]]> http://www.danielandrade.net/2010/03/13/speeding-up-a-dc-engine-with-magnets/feed/ 0 Building an Breathalyzer with MQ-3 and Arduino http://www.danielandrade.net/2010/03/07/building-an-breathalyzer-with-mq-3-and-arduino/ http://www.danielandrade.net/2010/03/07/building-an-breathalyzer-with-mq-3-and-arduino/#comments Sun, 07 Mar 2010 06:45:52 +0000 DanielAndrade http://www.danielandrade.net/2010/03/07/building-an-breathalyzer-with-mq-3-and-arduino/ During the First Meeting of Electronic Arts in Florianópolis, we built a Breathalyzer using the Alcohol Gas Sensor MQ-3 and a Arduino Board to use in the last day of the meeting, in which we gave a party. You can see a quick video two posts below. Last days I received many emails asking for the code or how to make one, so I decided to build the sensor again, take pictures/videos and make a tutorial showing how you can make one, so here it is.





Parts Needed:

  • Arduino Board
  • 10x 5mm LEDs (Green, Yellow and Red)
  • 100KΩ Potentiometer (to calibrate the sensor)
  • 10x ≈ 220Ω Resistor (anything between 220Ω and 470Ω is OK)
  • BreadBoard
  • MQ-3 Sensor from Sparkfun

Here are some pictures from the building process:

IMG_3025

IMG_3028

IMG_3029

IMG_3030

IMG_3042

IMG_3047

To make the LEDs work, I have connected them in sequence using the Digital Pins 2 till 11 (ten LEDs total). Remember to use a resistor between 220Ω and 470Ω for each LED, like shown on the picture below:

To connect the sensor, you have to connect one of the H pin to +5V Supply (use an external power supply for that, it may be too much current for the arduino) and the other one to Ground.


Pin B (any of them) you connect to Ground. And the A pin (also any of them) you connect to the 100KΩ potentiometer as shown on the picture below. In the same pin where you are connecting the pin A, you need to connect a wire to the Analog/Digital Converter in Arduino, that is where you are going to read the Alcohol information.

This is a quick and easy DIY project, but if you have any problem building it, please feel free to post questions!

You can DOWNLOAD the .PDE file HERE.


/*

@ Code for interfacing Alcohol Gas Sensor MQ-3 with Arduino
@ Code by Daniel Spillere Andrade and Daniel Amato Zabotti
@ daniel@danielandrade.net / danielzabotti@gmail.com
@ www.DanielAndrade.net

*/

const int analogPin = 0; // the pin that the potentiometer is attached to
const int ledCount = 10; // the number of LEDs in the bar graph

int ledPins[] = {
10,9,8,7,6,5,4,3,2,1 // Here we have the number of LEDs to use in the BarGraph
};

void setup() {

for (int thisLed = 0; thisLed < ledCount; thisLed++) {
pinMode(ledPins[thisLed], OUTPUT);
}}

void loop() {
//This is the code to light up LED's
int sensorReading = analogRead(analogPin);

int ledLevel = map(sensorReading, 500, 1023, 0, ledCount);

for (int thisLed = 0; thisLed < ledCount; thisLed++) {

if (thisLed < ledLevel) {
digitalWrite(ledPins[thisLed], HIGH);
}

else {
digitalWrite(ledPins[thisLed], LOW);
} }}

And now, have a great drinking!!!

Remember, if you gonna drive, don’t drink,
but if you do, call me! :P
IMG_3052

]]> http://www.danielandrade.net/2010/03/07/building-an-breathalyzer-with-mq-3-and-arduino/feed/ 18 Campus Party Brazil http://www.danielandrade.net/2010/01/27/campus-party-brazil/ http://www.danielandrade.net/2010/01/27/campus-party-brazil/#comments Wed, 27 Jan 2010 18:48:31 +0000 DanielAndrade http://www.danielandrade.net/2010/01/27/campus-party-brazil/ Hi everyone, I am blogging live from the CampusParty Brazil 2k10 in São Paulo – Brazil, it’s something like a Lan Party but full of presentations, concerts and of course downloading… We have here a 10GB BandWidth internet, and there’s a TV screen showing the bandwidth consumption, and we haven’t used more then 3GB at the same time. (I’m trying my best to beat the record). Another thing that I found cool is that someone started a DC++ Servers, and there’s around 400 people connected to it sharing stuff fullspeed, soon my 500Gb Lacie Drive, that I brought with me empty will be full.

In case you are somewhere around the world and would like to download stuff from us, connect to the DC++ Hub cp2010.no-ip.org and download at a great speed.

Today morning there was some people doing Arduino projects, DIY stuff, Open Sorce presentations and much more. You can check LiveStreaming from the Campus Party Here.

Yesterday Kevin Mitnick was here giving a presentation about the art of deception, what a presentation, really good! If you would like to watch it, I am uploading it too, it’s worth it!

Also I am uploading my pictures to my Flickr acc.

Take care all, I will check my downloads now! ;)

]]> http://www.danielandrade.net/2010/01/27/campus-party-brazil/feed/ 0 I Meeting of Electronic Arts http://www.danielandrade.net/2010/01/21/i-meeting-of-electronic-arts/ http://www.danielandrade.net/2010/01/21/i-meeting-of-electronic-arts/#comments Thu, 21 Jan 2010 13:56:55 +0000 DanielAndrade http://www.danielandrade.net/2010/01/21/i-meeting-of-electronic-arts/ It happened last week, starting on Monday 11th January and finishing on Friday the 15th, the I Meeting of Electronic Arts, where people from many differet places of Brazil came to see what was going on. Our first idea was a meeting (de)constructive, build, hack, modify, learn, teach, freedom of knowledge. Several workshops were presented, Basic Electronics, Processing, PureData, and others (the videos of the presentations will be distributed when people finish editing).

On Tuesday night we made a walking trip crossing the dunes till we find Joaquina’s beach. After swiming in the cold waters, we walked back on a thick rain, amazing, it was long ago since the last time I walked on the rain wanting it!

We learned/teched a lot in this event, one thing that we’ve noticed is that creative minds work much better after midnight. There was no point planning anything for the morning because no one could wake up before 11h.

On Thursday night a party was organized, where we put in for a test some projects developed during the event, for example a Breathalyzer using a Alcohol Gas Sensor MQ-3 sensor, LEDs and an Arduino. By the way, never seen so many arduinos in one place, in different sizes and colors, beautiful!

You can check some pictures from my Flickr:

Here is also a Video from the Breathalyzer (I will make a post on how you can make one after the Campus Party next week)

Some more videos can be found on my Vimeo.

]]> http://www.danielandrade.net/2010/01/21/i-meeting-of-electronic-arts/feed/ 1 The Longest Way 1.0 by Christoph Rehage http://www.danielandrade.net/2009/12/31/the-longest-way-10-by-christoph-rehage/ http://www.danielandrade.net/2009/12/31/the-longest-way-10-by-christoph-rehage/#comments Thu, 31 Dec 2009 16:12:42 +0000 DanielAndrade http://www.danielandrade.net/2009/12/31/the-longest-way-10-by-christoph-rehage/ Christoph Rehage had an idea of going by foot from Beijin to Germany. He took some shots on his way and afther the trip, made a video. I saw this today and got amazed, so I decided to share with you guys.

also I want to you all to have a Happy New Year and a great 2k10!!!

]]> http://www.danielandrade.net/2009/12/31/the-longest-way-10-by-christoph-rehage/feed/ 0 10 Cool things to do in OSX Terminal http://www.danielandrade.net/2009/12/21/10-cool-things-to-do-in-osx-terminal/ http://www.danielandrade.net/2009/12/21/10-cool-things-to-do-in-osx-terminal/#comments Mon, 21 Dec 2009 16:02:20 +0000 DanielAndrade http://www.danielandrade.net/2009/12/21/10-cool-things-to-do-in-osx/ The thing that made me buy mac is that it has a OS based on Unix, and programs like Photoshop and Microsoft Office (not a big OpenOffice fan yet). Like a good nerd, I can’t live without my beloved terminal, which makes my life easier. In this post I will show some commands so you can have fun on mac’s terminal. Hope you like it, and if you have any other ideas, please comment on the post!

1. Twitter Update

    Nothing more geek than updating your twitter from terminal. Just change the user e pass from the code. Way cool.
    curl -u user:pass -d status="Tweeting from the shell" http://twitter.com/statuses/update.xml

2. Sing songs

    Release your creativity, sing along.
    sudo osascript -e 'say "Dum dum dum dum dum dum dum he he he ho ho ho fa lah lah lah lah lah lah fa lah full hoo hoo hoo" using "Cellos"'

3. Download from a unstable server

    You know, sometimes you are downloading a big file, but it keeps failing, and you always have to hit RESUME. Your problems are over, with this code, if the download stops suddenly, it will automatically restart. This code have a 15kbps speed limit, delete –limit-rate 15k to remove the speed limit.
    while ! curl -C - -O --limit-rate 15k file-address-goes-here; do sleep 10; done

4. Secure SSH Tunnel

    This is very important if you are using a public/open wireless connection. If you want to access your bank information or online shopping, making sure no one is stealing your information, then SSH Tunneling is the solution. You can find more information HERE.
    ssh -D 8080 -f -C -q -N myuser@myserver.com
    From: Stammy

5. Real-time view of a running processes

    To know what is running on your computer, how much memory and processing, just hit:
    top

6. Resize pictures

    One quick way to resize pictures in a batch is using a simple program called SIPS. In this example, I’m resizing all pictures .JPG to a 500 pixels width. For more information, type on terminal man sips
    sips --resampleWidth 500 *.JPG

7. Build a fast and simple HTTPD server

    If you want to start a simple HTTPD server on the 8080 port, go to the folder you want to show and use the command:
    python -m SimpleHTTPServer 8080

8. Kill a process

    When using top, you have access to the processes ID, and if they are using too much RAM (for example), you can kill it.
    killall firefox
    kill 234

9. Watch Star Wars Episode IV

    No comments on this one :)
    telnet towel.blinkenlights.nl

10. Show hidden files (those with . in front of the name) in Finder

    defaults write com.apple.finder AppleShowAllFiles TRUE

Thanks for readying.

]]> http://www.danielandrade.net/2009/12/21/10-cool-things-to-do-in-osx-terminal/feed/ 1 Rare Earth Magnets http://www.danielandrade.net/2009/10/01/rare-earth-magnets/ http://www.danielandrade.net/2009/10/01/rare-earth-magnets/#comments Thu, 01 Oct 2009 02:56:07 +0000 DanielAndrade http://www.danielandrade.net/2009/10/01/rare-earth-magnets/ This is a totally random movie I shot this morning after receiving some Magnets from DealExtreme. Tomorrow I will measure the force of this magnets with a “Gaussimeter”, then let you guys know.

]]> http://www.danielandrade.net/2009/10/01/rare-earth-magnets/feed/ 0 Google: 13 years in 2 min http://www.danielandrade.net/2009/08/19/google-13-years-in-2-min/ http://www.danielandrade.net/2009/08/19/google-13-years-in-2-min/#comments Wed, 19 Aug 2009 12:59:02 +0000 DanielAndrade http://www.danielandrade.net/2009/08/19/google-13-years-in-2-min/ Great movie!

]]> http://www.danielandrade.net/2009/08/19/google-13-years-in-2-min/feed/ 0