DanielAndrade.net

Rare Earth Magnets

DanielAndrade — Thu, 01 Oct 2009 02:56:07 +0000

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.

Google: 13 years in 2 min

DanielAndrade — Wed, 19 Aug 2009 12:59:02 +0000

Great movie!

Ultrasonic Range Finder with Arduino

DanielAndrade — Sun, 26 Jul 2009 16:52:12 +0000

I recently got a Maxbotix LV-EZ4 Ultrasonic Range Finder to try understand how to use it with my little Arduino. Having a ultrasonic range finder can be very useful in many different projects, as it can detect objects, I can use it to make alarm systems (cars usually use this kind of sensor), Obstacle-Avoiding Robot and many other things that you may have in mind. It works better outdoors then the IR sensor, but the only thing I could notice is that it doen’t detects very well some thick carpets. Besides that, it’s a great sensor. From the datasheet we can read that it sonar range information from 6-inches out to 254-inches (15.24 cm - 6.452m).

Maxbotix Features:

42kHz Ultrasonic sensor
Operates from 2.5-5.5V
Low 2mA supply current
20Hz reading rate
RS232 Serial Output - 9600bps
Analog Output - 10mV/inch
PWM Output - 147uS/inch
Small, light weight module

Docs:

How the Sonar works:
It basically sends a high frequency wave in one direction, the wave hits a object that reflects the wave. When the wave gets back to the sensor, it calculates the distance depending on the time it takes to go and back. More information can be checked at Wikipedia.

Working with Arduino:

I think the easiest way to work with the sensor is using the Analog Output Mode, where you just need to give the sensor some juice connecting with the 5V and Ground, and the Analog Output on any Analog-Digital Converter pin on the Arduino. Where it gives (Vcc/512) / inch where I am using 5V, so it’s 10mV/inch. But the AD from the Arduino have 1024 steps from 0-5V. So to have the information from the sensor in inches we need to make ADvalue/2 and if you want to have the information in cm, just multiply the previous value for 2.4 (1 inch = 2.4 cm).

Pics:

Video:

So here is the code:
You can download the file HERE.

@ Code for interfacing arduino with a Maxbotix LV-EZ4 Ultrasonic Range Finder
@ Code by Daniel Spillere Andrade
@ www.danielandrade.net -=- daniel@danielandrade.net

int blinkLed=13; // Where the led will blink
int sensorPin=0; // Analog Pin In
int sum=0; // Variable to calculate SUM
int avgrange=50; // Quantity of values to average
int sensorValue; // Value for te average
int i,media,d; // Variables
float cm,inch; // Converted to cm

void setup()
{
Serial.begin(9600); // To check what is being read on the Serial Port
}

void loop() {

d=analogRead(sensorPin); // Read the analog value
digitalWrite(blinkLed,HIGH); // Turn on LED
delay(d); // Delay changes with the analogread
digitalWrite(13,LOW); // Turn off LED
delay(d); // Another delay

cm = (d / 2) * 2.4; // Convert the value to centimeters
inch = d/2; // Value in inches

Serial.println(cm); //Print average of all measured values

// This is the code if you want to make an average of the read values

for(i = 0; i < avgrange ; i++) {
sum+=analogRead(sensorPin);
delay(10);
}

media = sum/avgrange;
Serial.println(media); //Print average of all measured values

sum=0;
media=0;

}

Thanks for reading, and don’t forget to visit www.electronicslab.org

The history of hacking

DanielAndrade — Sat, 04 Jul 2009 01:43:51 +0000

If you have 50 minutes of your day, you really should watch this Discovery Channel`s Documentary, about the history of hacking, about the Phone Phreaking. Amazing!

10A on a .7 graphite -> ElectronicsLab.org

DanielAndrade — Tue, 09 Jun 2009 23:09:51 +0000

Hi, me and some friends from university, we just started a new blog called electronicslab.org where we will add some cool things we do over the weekends and holidays, also telling our discoveries and learning’s. Down, you can watch a short but really cool video (at least was cool making it), were we connected a 0.7 graphite to a power source and made 10A go through it!

Don’t forget, add www.electronicslab.org to your rss reader and get ready for some cool stuff

Solving problemas with PhPMyadmin on Ubuntu

DanielAndrade — Tue, 09 Jun 2009 11:35:57 +0000

You know, everytime you want to install LAMP + phpmyadmin on Ubuntu, you can simply write on terminal:

sudo apt-get install apache2 mysql-server-5.0 php5 php5-mysql phpmyadmin

Ok, you are ready to go, but the only problem is that you can’t find the phpmyadmin folder when accessing http://localhost/ you can’t even see the folder at /var/www/ . So what you should do is:

sudo ln -sf /usr/share/phpmyadmin/ /var/www/phpmyadmin

It will link the phpmyadmin folder from /usr/share/phpmyadmin/ to /var/www/phpmyadmin
now try going to http://localhost/phpmyadmin and you are good to go!

Energy efficiency a MUST

DanielAndrade — Thu, 07 May 2009 19:45:37 +0000

Review: Lacie Pocket 500gb External Drive

DanielAndrade — Sat, 21 Feb 2009 04:42:52 +0000

Some days ago I bough the Lacie Pocket 500gb external hard-drive, and since then I have been very happy with my purchase. The HD is small enough to fit any pocket in my bag (3.19 x 0.71 x 5.08 inches [WxHxD]) and with the weight of 3 pounds, it makes easy to take everywhere. I know that having an external notebook hard-drive isn’t the safest way to store you precious data, but its a great place to store music, videos and photos in which you can take anywhere. At home I have my HTPC (Home theater PC) with a lot of free storage, so what I do is, I have a backup of all my data on the external lacie drive, and another copy of my precious things on my HTPC, this way I hope all my information is safe (I am also thinking on having another copy on the clouds [amazon s3]). Everything is backed up using a simple bash script made by me that will make copies to the external drive and to my media center via FTP.

Lacia Pocket drive comes just with a USB 2.0 cable (no firewire [no problem, new macbooks dont have them anyway]), and uses it to power the HD and to transfer data. That was one of the things I was looking for when buying it, some external drive that you don’t need to go everywhere with a power supply just for the device. If your USB port doesn’t have enough juice to power the hd, you can use another port just to power it. This problem usually happen when you try connecting some device that requires more energy to a USB hub.

As I am planing to use it on Linux/Windows/Macs, I formatted it it as FAT32, even knowing it only accept files smaller then 2^32-1 bytes (what sucks when downloading huge High-Def movies). The drive is a 5400RPM 2.5-inch, so you shouldn’t expect it to be really super fast, but the speed is decent and works for me.

Here you can check some more pictures of this gadget, enjoy.

Arduino Wallpapers

DanielAndrade — Thu, 19 Feb 2009 00:28:21 +0000

Just having some fun with photoshop, I made a wallpaper for the Arduino lovers out there. If you have any ideas or different color you would like to have it, just leave a comment with the #code you want.

Hope you liked

[1024×768] [1280×1024] [1280×960] [1280×800] [1600×1280]

MAKE presents: The LED

DanielAndrade — Sat, 22 Nov 2008 16:14:59 +0000

As you might already know, I am big of a LED fan, love all it’s light power and low power needed for that. While viewing the RSS from
HackZine I saw a great short video about the history of LEDs and a little about how to use them. I liked, and decided to share with you, hope you likes as much as I.

In case you would like to learn more about leds, you can visit HowStuffWorks and on Wikipedia.

Some projects I’ve used with leds:

HowTo: Blinking LEDs

HowTo: Make your own Metronome

DIY: Binary Clock with Arduino