Buttons

There are two main types of buttons, one with 2 pins, and one with 4 pins.

As you can hopefully see, the 4 pin button will fit on a breadboard much more nicely, so I will use that but the 2 pin button can be connected with some basic wire. With the 4 pin button you just need to use the two pins on the same side, and it doesn't matter which side is positive/negative.

Here is a basic circuit diagram for the button:

We can use the serial monitor to tell us when the button is pressed. An LED could be used as well but this is a good introduction on how to use the serial monitor. The code can be downloaded below. When the button is pressed it will print a message to the serial monitor which can be opened with Ctrl+Shift+M in the Arduino IDE.

Download Code

Switches

Switches are pretty basic, and an example can be seen below. I have attached some basic 22AWG to it so that it is easier to hook up to my breadboard.

I will use the same basic circuit that was used with the Basic LED program, but a switch is added before the resistor as seen below:

Here is a video of it in action:

www.youtube.com/watch?v=Lo2p9SurjYk

Download Code

Potentiometers

Potentiometers have 3 pins: positive, negative and position (usually the middle). This can be seen below:

The outside potentiometer pins gets hooked up to the 5V power pin and ground while the middle one gets hooked up to A0. The LED gets hooked up exactly the same as before.

In my example I control the brightness of an LED with the potentiometer. This can be seen below:

www.youtube.com/watch?v=2LfX82yS7UQ

Download Code

To fix this problem you have to edit the Arduino startup script, which in my case is located at "/usr/share/arduino/arduino". The last line of this file looks like this:

java -Dswing.defaultlaf=com.sun.java.swing.plaf.gtk.GTKLookAndFeel processing.app.Base

and it needs to be changed to this:

java -Dswing.defaultlaf=com.sun.java.swing.plaf.gtk.GTKLookAndFeel processing.app.Base "$*"

Finally I had to change my "/usr/bin/arduino" from:

/usr/share/arduino/arduino

to

/usr/share/arduino/arduino "$*"

Now you should be able to associate .pde files with the Arduino IDE and have them automatically open.

LEDs are used in many applications and can be very useful when debugging. Turning on an LED can be compared to writing "Hello World" or some other test statement to the terminal window. LEDs have a positive end (the longer one) and a negative end (shorter). When hooking up a circuit make sure that the LED has the correct orientation.

My LEDs are rated at 3.4V, and the Arduino supplies 5V at the DC output. Most LEDs require about 20mA of current to flow through them. If you allow more current to flow through then it will shine brighter but it will also burn out / stop working more quickly. If you allow less then the LED will not shine as brightly and if using a battery it will last longer. Using Ohm's Law we can calculate:

(V₂-V₁) / I = R

and substituting in we get:

(5-3.4)/0.02 = 80Ω

I will use a 100Ω resistor because that is the closest thing I have over 80, and as mentioned previously this will just cause the LED to shine a little dimmer. I have created the circuit diagram below for a single LED:

To turn on multiple LEDs from the same source, they must be connected in parallel (each with its own resistor). This can be seen below:

You can see below how I hooked up my circuit (sorry for the poor picture quality). There are multiple ways to do it, so it doesn't have to look exactly like this.

Now that the circuit is all hooked up it is time to program it. With only LEDs there isn't much to do, so we will just turn it on / off with a delay. The code and circuit diagrams can be downloaded below. I tried to make the functions as modular as possible even though they are not really needed in this basic example.

Download

And here is a video of it in action:

www.youtube.com/watch?v=G0p374ncKGY

Accessors:

• height()
• width()
• retrieve(n, m)
• print()

Mutalators:

• insert(n, m, x)
• resize(n, m)

Download

I have a good theoretical knowledge of circuits, and after two classes on them I can tell you the voltage or current at any point in almost any circuit. I know opamps and transistors like the back of my hand, but designing a circuit from scratch was surprisingly never covered.

After some quick reading and installing the software it seems like the Arduino programming language is heavily based off of C/C++ which is good because I don't have to relearn any syntax.

Hopefully I will start posting some basic accomplishments soon such as turning on LEDs.

• Single Linked List with Single Node
• Undo Redo Stack (uses Single Linked List and Single Node)
• Double Linked List with Double Node
• Dynamic Queue as Array
• B Tree with B Tree Node
• Dynamic Double Hash Table
• Weighted Graph (can find the minimum spanning tree)

To use, just compile it and then run it like this (use appropriate coordinates):
./Jail 0 0 1920 1080
Note that the mouse might jump outside those boundaries for quick moments so use:
./Jail 0 0 1917 1080

Download

Download

All the streams and stream names can be customized easily via a ~/.streams file, and the amount you wish to have is flexible. You are also not limited to di.fm streams, any stream should work.

This project is still in an alpha stage. As of now:
-Recording doesn't work.
-Statusbar text doesn't scroll.
-The ~/.streams file is  in the same directory as the script to make testing easier.

If you find a bug, problem, something you would like to have or a way to fix the above problems please let me know.

Python, wxpython and gstreamer are required.

Download

#! /bin/bash
sudo ifconfig wlan0 up
sudo iwlist wlan0 scan | grep ESSID: | while read line
do
    essid="${line:7:$((${#line}-7-1))}"
    #echo $essid

    if [ "$essid" == 'WLAN' ]; then
        sudo netcfg maya
    fi
    if [ "$essid" == 'eduroam' ]; then
        sudo netcfg eduroam
    fi
    if [ "$essid" == 'D3GN_SSID0' ]; then
        sudo netcfg home
    fi
    if [ "$essid" == 'Gunnewiek' ]; then
        sudo netcfg Gunnewiek
    fi
done