Chrome Sign In

For students having trouble signing into Chrome with their DSBN account, enter this address directly into the Chrome address bar and you should be able to sign in properly:


Why sign into Chrome?

It will sync your bookmarks and Chrome extensions so wherever you are logged into Chrome (other classes, at home, on your laptop) everything will be sync’d.

Computer Hardware Safety Rules


When installing/removing computer hardware and other peripherals:

  • Wear proper apparel. Avoid acrylic or wool sweaters when working with electronic parts. Do not wear loose fitting clothing, rings, bracelets etc.
  • Unplug all computer equipment and peripherals before opening any covering cases.
  • Keep your work area clean and well lit.
  • Check for damaged parts.
  • Do not force components into computer ports.
  • Use an anti-static wrist strap or discharge yourself by touching a grounded metal object such as a computer casing.
  • Power supplies produce several levels of voltage. Read the information on the power supply carefully and make sure that the power supply you are using is appropriate for the application.
  • Replace all cases or coverings after inspections or installations.
  • Check all circuits and installations with the instructor before power is applied.
  • Retain all screws during disassembly in containers such as film canisters for proper reassembly.
  • Electronic components should never become hot. Hot components means that there is a problem with the circuit. Disconnect any power immediately.

The most important safety rule of all: Always Be Careful! (ABC)

(from ICE4M Supplemental Profile Unit 1, Appendix 1.1.1)

(image from

Resistor Colour Code

Color Digit value Multiplier Multiplied Out Tolerance
Black 0 100 1
Brown 1 101 10
Red 2 102 100
Orange 3 103 1,000
Yellow 4 104 10000
Green 5 105 100,000
Blue 6 106 1,000,000
Violet 7 107 10,000,000
Gray 8 108 100,000,000
White 9 109 1,000,000,000
Gold ±5%
Silver ±10%

See also for an online resistance calculator.

Arduino PWM Activities

LED Dimmer

Using the Arduino reference page as a starting point, research the basics of how to use pulse width modulation (PWM) on the Arduinos.

For this activity, you will wire up a potentiometer so it controls the brightness of an LED.

From the relevant page on the Arduino website you should be able to find enough information to wire and program this activity yourself.

Light Sensor

This activity is simply adapted from the LED Dimmer activity, but you will be using the light sensor in place of the potentiometer.

Note that the light sensor input will have to be “scaled” so that when the sensor is covered (dark) the LED will fully lit and when it is uncovered the LED is fully off.

The Design Process

Design Process

This design process model is based on the Ontario 2008 Technological Education curriculum.

From the curriculum:

“Although processes such as this involve a framework of sequential steps, they are typically iterative processes that may require a retracing of steps, diversions to solve specific problems along the way, or even a return to the start of the process if it becomes clear that the situation needs to be clarified and the problem redefined. Problem solvers soon discover that the process calls for an open mind, the freedom to be creative, and a great deal of patience and persistence.”

The graphic above is based on one created by Jackie Griffith. Thanks to Jackie for allowing me to adapt it.

Click here to take a comical look at the design process!

How to Install Apache (on Linux)

Type each of these commands into a terminal window:

sudo apt-get update
sudo apt-get install apache2

To check if Apache is running, enter either or localhost into your web browser.

How To Install KompoZer (on Linux)

(Adapted from

All the commands listed on this page must be entered by copying and pasting into a terminal window.

First, install the dependencies:

sudo apt-get install libatk1.0-0 libc6 libcairo2 libfontconfig1 libfreetype6 libgdk-pixbuf2.0-0 libglib2.0-0 libgtk2.0-0 libidl0 libnspr4 libnss3 libpango1.0-0 libpng12-0 libstdc++6 libx11-6 libxft2 libxinerama1 libxrender1 libxt6 zlib1g

Then, get the two packages, and install them in the correct order. (Copy and paste each line individually.)

For 32 bit systems:

sudo dpkg -i kompozer-data_0.8~b3.dfsg.1-0.1ubuntu2_all.deb
sudo dpkg -i kompozer_0.8~b3.dfsg.1-0.1ubuntu2_i386.deb

For 64 bit systems:

sudo dpkg -i kompozer-data_0.8~b3.dfsg.1-0.1ubuntu2_all.deb
sudo dpkg -i kompozer_0.8~b3.dfsg.1-0.1ubuntu2_amd64.deb

You will now find KompoZer in the menu.