A brief introduction into electronics for web developers which allows you to control circuits from a web-based interface.
Download the code samples from the GitHub Repository
PresentationsMini Maker Faire Elephant & Castle
Original presentation: PowerPoint file. This tutorial has been formatted to suit web browsers.
|10x||Lengths of wire
(red, blue, black, etc.)
(to connect to a router)
|1x||5v Micro USB Power Cable|
|1x||Raspberry Pi (Model B)|
|1x||Tactile push button switch|
|1x||Resistor for LEDs
(find out more later)
(one for the Raspberry PI, one for the HDMI monitor)
|1x||Raspberry Pi Cobbler|
Slot in your Raspberry Pi Cobbler in to the breadboard.
With red wire, connect your 3V3 to the closest inside bus strip (or on the bus strip with the red line).
With black wire, connect your GND to the closest outside bus strip (or on the bus strip with the blue line).
So that power can be shared on both sides, we can wire the opposing bus strips.
For this example, we can calculate our resistor value. You will need to find your forward voltage and current from your diodes.
Values from LED
Forward voltage: 2V
Forward current: 20mA
This information should be printed on the packet or included on instructions with your LEDs.
Values from LED
Source voltage: 3.3V
3.3V is the standard voltage for the Raspberry Pi
5V is the standard voltage for Arduino (if you're using that)
Using this information, we would have to use a 68Ω resistor.
If you don't have a 68Ω resistor available, you can increase the resistance to a nearby value (e.g.: 75Ω) but do not decrease the resistance (e.g.: 62Ω).
Insert the LED in to the breadboard across two separate terminal strips. Observe which side is positive and place that closer to the Cobbler.
Wire the Cobber pin #22 to the positive pin on the LED.
Connect the negative pin of the LED to the GND bus strip using your 68Ω resistor.
Insert the tactile push button switch across the central gutter of the breadboard.
Wire the Cobber pin #23 to the button leg closest to the Cobber pin.
Connect your 10KΩ resistor from the right side of the button leg to the GND bus strip.
Wire the button leg opposing the resistor to the power bus strip (3.3V)
A web application framework for Node.JS which helps to handle HTTP requests, limiting the amount of work you need to do in order to get and application up and running.
Allows for easy implementation of HTML files to include dynamic data. Those familiar with PHP, ASP and ERB (rails) will appreciate EJS.
Enables real-time communication between websites and your Node.JS application.
Lets Node.JS communicate with the GPIO (General Purpose Input/Output)