Sebastian Patten

Node.js sharing JavaScript code between client and server

admin — Wed, 14 Dec 2011 00:39:35 +0000

I first looked at Node.js because it sounded like they had bridged the gap between client side (browser) and server side (Node.js). Code re-use is one of the core principles of developing software and for some reason it has taken us this long to get to a point where we can write one language that can be reused on both server and client side.

My initial impressions of Node.js bridging this gap weren’t great. Node.js does a good job of running stuff server side in JavaScript, but finding documentation on how to share code has been a slow process. The documentation on their website doesn’t mention sharing of code between client and server.

Current state of affairs

Node’s server side code exposes public methods/properties with a module pattern

If you want to expose a public method called doCoolStuff in your Awesome.js file you might do this:

exports.doCoolStuff = function() {

// Cool stuff done here...

};

However when we go to run Awesome.js on the client – it’s not going to know anything about what an exports is.

Solution

There are various ways around this such as checking whether exports exists, if it doesn’t define it etc… (read more here)

My preferred solution is to use Require.js and kill many birds with one stone. From the web browser point of view, Require.js is really helpful in that it:

Allows us to asynchronously load JavaScript resources
Allows you to get rid of script includes from your HTML
Negates the issue of having to order JavaScript files one after the other
Greatly improves on the ability to test our code by swapping out concrete implementations with mocks/dummys
Cleans up your code a lot
Better way of specifying modules

Also we can use the same code on the client and server (Node.js).

Setting up the Server Side (Node.js)

I tried to install via NPM a la – npm install requirejs, however NPM couldn’t download and unpack the files for some reason.

To get around this I downloaded the r.js code for node directly from the Require website, renamed to index.js and placed it in a folder called Requirejs in the node_modules folder. I renamed it to index.js as node will automatically look for a file called index.js in folders in node_modules.

Server Side Code – Server.js

var requirejs = require('requirejs');

// Boiler plate stuff - as per r.js's instructions
requirejs.config({
    //Pass the top-level main.js/index.js require
    //function to requirejs so that node modules
    //are loaded relative to the top-level JS file.
    nodeRequire: require
});

// We are requiring Person, instantiating a new Person and then
// reading the name back

// As Person.js is a module, we dont need the .js at the end
requirejs(["/Path/To/Person"], function(Person) {
	var person1 = new Person("Seb");
	console.log(person1.getFirstName());
});

Code that can live on client or server – Person.js

define(function() {
	return function(firstName) {
		var _firstName = firstName;
		
		this.getFirstName = function() {
			return _firstName;
		};
	}
});

HTML Page



    
        My Sample Project
        
        
    
    
        My Sample Project

JavaScript for the HTML Page – Main.js

// We are requiring Person, instantiating a new Person and then
// reading the name back

// As Person.js is a module, we dont need the .js at the end
require(["/Path/To/Person"], function(Person) {
	var person1 = new Person("Seb");
	console.log(person1.getFirstName());
});

Tips For Writing Software And General Business Heuristics

admin — Tue, 05 Jul 2011 22:36:11 +0000

The most simple route is the best 99% of the time (this might not be the case with life-critical systems such as space shuttle )
Think about every possible detail before you write one line of code. Plan out all the method names, what they will interact with etc… Its far quicker and cheaper to go through many iterations in your head and on paper than it is to do it on a computer
If you use a technology – make sure you go and learn every facet and feature of it
When being tasked with something challenging that you don’t fully understand and need to get clarification on – question the Subject Matter Expert (or whoever knows the most about the task at hand) as much as you can early on – till you see the big picture. Personal experience has shown me that by asking a question here or there over a long period of time will aggravate people whereas if you ask the same number of questions in a short period of time, people don’t get wound up
Never ask some one a question without asking yourself first. E.g. you should always have your best answer figured out before hand
If you do ask some one a question, don’t include any answers that you think it might be in your question. Compare their answer with yours. Good example: “What is the best way to create a widget?” Bad example: “Should I create a widget by using a wizard? Or should I download a pre-made widget?” The Good example leaves a question open ended. The person replying to your question might give you an answer you had not even thought about. You may even learn something new. The bad example pre-loads the question and narrows the scope of available answers.

If something feels too tough – its because you don’t know enough about it. Go away and read as much as you can about the subject.
If you have any small doubt when approaching a problem, you are likely taking the wrong approach. Tune into your gut feeling
If you see repeating code ignore it the first and second time you see it. Third time – refactor it and get rid of the repeating code
Don’t ever follow other people’s opinions. Read all about it then make up your own mind. This leads to confidence
Use version control systems to check in as often as possible to a branch. Its way quicker to revert back a few steps than to go and undo code manually
Use diff tools such as Beyond Compare to compare two files or two file systems. Don’t ever do it by eye
Be dependable. If some one asks you to do something. Make it your absolute goal to get it done for them
If you are seriously stuck on something, ask for a colleagues help. A lot of the time it can be something very trivial which you have overlooked
If you are stuck on a complex problem try thinking about it pretty hard just before bed. You will fall asleep and wake up with the problem solved
Teaching is the best way of learning. Write a blog or teach your colleagues something new
Do software projects that you find fun in your own time. Learn new technologies and processes all the time

Highlight the current line in Visual Studio 2010 with Resharper

admin — Fri, 17 Jun 2011 03:41:12 +0000

Highlighting your current line makes it loads easier to see where you are on the page. I first noticed that I liked the idea of line highlighting when I installed the Productivity Power Tools via NuGet. I ended up turning all the options off except for the highlighted line due to slow performance on my machine. Then I realized that I could get the highlight using ReSharper with Visual Studio.

Steps

Step 1) Resharper > Options > Editor > Check the Highlight current line checkbox
Step 2) Tools > Options > Environment > Fonts and Colors > ReSharper Current Line Highlight. Choose the foreground and background colors you want to apply.

Building a Website Like a Boss (Part 1)

admin — Fri, 10 Jun 2011 22:57:17 +0000

Links to tutorial parts

Building a Website Like a Boss

Background

This series of blog posts will cover how I am building my side-project web application. I am documenting it because I am using some technologies and methodologies that are really powerful when used together. And hey, it might be useful to someone .

It all started off with me learning ASP.NET MVC and then trying to apply Domain Driven Design (DDD) to it. I conceptually got the ideas talked about in DDD, but found it really troublesome applying the theory to a physical implementation. I spent a good deal of time playing around and researching how this could be achieved. I don’t think I was the only one struggling with this – I found a really good series on MVC by Rob Conery where he also struggled with trying to architect a perfect solution.

Soon after my fruitless attempts at creating a text book example of DDD in a web application, I was pointed to CQRS and Event Sourcing in a passing conversation with a colleague. From initially learning these two new words, I went away and did a lot of reading and learning. Learning these new technologies and processes made everything click together and I think that the architecture should really excite you for the following reasons:

What The Architecture Offers

Any interactions with the system are persisted. This means you can replay the entire system to any point in time. Say the business people come to you with a hypothesis that website users are 95% likely to buy an item that they removed from their shopping cart within 5 minutes of placing their order. You can include this logic, replay all events and see whether it is true or not. Its Business intelligence on roids! Or if a client reports a weird bug that you cannot see, you can just replay the events and step into the code at any point in time!
Data is stored in the database as JSON, which means it can be handed straight to the UI. E.g. a jQuery AJAX call to a URL which MongoDB services the request and returns straight up JSON. No need for request -> back end code -> more back end code -> goes through an asp.net repeater -> rendered in html.
Data in the website is all de-normalized, which means there are no queries going on for requests Yes you read that right. Begone Get.all.stuff.where.blah.isnot(5).insersects(something).on(lame==true); (Disclaimer: That wasn’t code – but you get the idea).
Utilizes a NoSQL document database which is seriously fast
The system broadcasts all events, which gives you a true SOA foundational architecture
True data ignorance – start modelling the domain first, you can ignore what the data model looks like
Using BDD you can communicate what the application will do in a format that any one can understand (this really helps with documentation too)
The domain objects will not have unnecessary CRUD methods/information in them. They will be purely used for modelling business logic. Nothing more.
I’ll never need to worry about transactions (in business logic)
The underlying Enterprise Service Bus means that no user intention is lost and everything is transactional
You implicitly get a full blown audit log from the previously mentioned fact
Fully Asynchronous – which means scalability and speed
Software becomes more scalable – Faster reads from data lead to a far more responsive website

Sneak Peak/How Do We Do This?

In the upcoming posts I will be covering the following technologies and approaches (don’t worry if you are not familiar with some of them – all will become clear with time).

ASP.NET MVC
Domain Driven Design – DDD
CQRS
MSMQ
NServiceBus
Event Sourcing
Behaviour Driven Development – BDD
MongoDB & Fluent Mongo
JSON
Knockout.js
JavaScript and jQuery
Some form of caching

Personal Goals for the Web Application

Implementation of best practices
Implementation of some new technologies (might as well try out some of these new technologies that have been coming out)
Robust
Logging/Audits
Scalable
Testable
Localization
Secure
Promote synergy – Like a Boss
As cheap licencing costs as possible

We’ll drill down into the details in the second post.

How to revise for MCTS 70-515 Web Applications with .NET 4.0

admin — Wed, 18 May 2011 02:48:37 +0000

Updated: I’ve re-uploaded my flash cards to WordPress. When you download the file, rename it to .anki (see the Anki application below). I wrote them for my personal use, so some might not make perfect sense, however I’m certain you will find them useful.

To prepare for sitting my MCTS the first thing I did was to ask as many of my colleagues (who have all taken many certification exams) about their approach to passing. The feedback was unanimous in that practise tests are the key to passing. This would be the backbone to my studying.

I bought the 70-515 Microsoft Self Paced training kit as a starting point. I would recommend the book as it was concise and covered 95% of the information that you need to know. Buy the book and read it cover to cover a few times.

After I was about half way through the book I asked around again as to which practise test provider I should use. My feedback was that Transcender was good quality and as it happened at the time had a 40% off deal through Microsoft Partners. I bought the practise tests and got to work running over and over them to get up to close to 100% correct. What I like about the Transcender package is that it comes with Flash cards which make you dig a bit deeper into your knowledge.

The actual MCTS 70-515 test is multiple choice, however with flash cards, you will be given a question and no options. Therefore you have to think. This thinking really strengthens those neural pathways and solidifies your memory.

I started off the process taking detailed, hand written notes. I soon found that was slowing me down and that It was slow to go back on them. With the knowledge that writing stuff down further helps your memory retention, and knowing that Flash cards were beneficial I found Anki which is a free piece of software that allows you to create flash cards. Instead of writing hand written notes I converted to writing them into Anki. I wrote my notes as meaningful questions, so that I could replay the flashcards and test my knowledge. Anki also will shuffle the ones that you get constantly correct to the back of the pack and the ones you get wrong more frequently to the front. /Win

I soon found that the book plus the test exams were not enough to pass. Reading MSDN proved to be very helpful as well as various blog posts. In particular the following post is an awesome listing of a huge swathe of items that you could be tested upon.

Part 1
Part 2
Part 3
Part 4
Part 5
Part 6

Make sure you do timed tests so that you have a feeling for how fast you should go. My test was 51 questions and I had 140 minutes to complete the test with the questionnaire and evaluation. It will take you around 10 mins to fill out the questionnaire and evaluation. Also worth noting, you can go forward and backward in the exam, whilst marking questions you want to come back to later. My approach was to go through all the ones I easily knew, marking down the ones I didn’t know or was unsure about. This meant I didn’t get anxious that I was spending too long on a hard question. I came back at the end to tackle all the odds and sods.

I found a decent approach to answering the multiple choice questions is that they usually give you 4 or 5 options. 2 of them will be blatantly wrong and the remaining possibilities will have subtle syntactical differences.

Each question in the exam is weighted differently and some of the questions aren’t even used in your score! The pass mark for the 70-515 was 700 out of 1000.

I hope this helps some one pass!
Good luck!

Difference between ASP.NET Data Controls

admin — Tue, 10 May 2011 16:35:49 +0000

Totally lame post, but I’m studying for my MCTS and thought this might help some one. Keep in mind the values in the matrices below are for out of the box ASP.NET – it doesn’t mean you can’t achieve certain functionality, by extending them.

Single Item Display

FormView

Property	Value
Multiple Items	No
Templated	Yes
Create	Yes
Read	Yes
Update	Yes
Delete	Yes
Sorting	No. It is a single item view, so there is no need.
Pagination	Yes, but it’s only one page at a time. Use the AllowPaging=”true” attribute to turn it on. Use the PagerSettings-Mode attribute to state the type (NextPrevious, NextPreviousFirstLast, Numeric, NumericFirstLast). Use the PagerSettings element within the FormView to specify paging options such as the text for the previous and next buttons.

References:
http://msdn.microsoft.com/en-us/library/ms227992.aspx

DetailsView

Property	Value
Multiple Items	No
Templated	No
Create	Yes
Read	Yes
Update	Yes
Delete	Yes
Sorting	No. It is a single item view, so there is no need.
Pagination	Yes, but it’s only one page at a time. Use the AllowPaging=”true” attribute to turn it on. Use the PagerSettings-Mode attribute to state the type (NextPrevious, NextPreviousFirstLast, Numeric, NumericFirstLast). Use the PagerSettings element within the FormView to specify paging options such as the text for the previous and next buttons.

References:
http://msdn.microsoft.com/en-us/library/s3w1w7t4.aspx

Multiple Item Display

Repeater

Property	Value
Multiple Items	Yes
Templated	Yes
Create	No
Read	Yes
Update	No
Delete	No
Sorting	No
Pagination	No

References:
http://msdn.microsoft.com/en-us/library/x8f2zez5.aspx

ListView

Property	Value
Multiple Items	Yes
Templated	Yes
Create	Yes
Read	Yes
Update	Yes
Delete	Yes
Sorting	Yes. You add a LayoutTemplate and set the button’s command name to “Sort”. Set the CommandArgument to the direction that you want sorting.
Pagination	Yes, use the DataPager control

References:
http://msdn.microsoft.com/en-us/library/bb398790.aspx

DataList

Property	Value
Multiple Items	Yes
Templated	Yes, but it does wrap the output in a table.
Create	No
Read	Yes
Update	Yes
Delete	Yes
Sorting	Yes, but you have to take care of this manually in your code behind.
Pagination	Yes, but you have to take care of this manually in your code behind.

References:
http://msdn.microsoft.com/en-us/library/es4e4e0e.aspx

References:
http://msdn.microsoft.com/en-us/library/bb398790.aspx

GridView

Property	Value
Multiple Items	Yes
Templated	No
Create	Yes
Read	Yes
Update	Yes
Delete	Yes
Sorting	Yes
Pagination	Yes

References:
http://msdn.microsoft.com/en-us/library/2s019wc0.aspx

Netduino Transistor Switch

admin — Wed, 23 Feb 2011 16:20:41 +0000

A transistor switch allows you to use a smaller flow of electrons to control a much larger flow of electrons. In this case, we are using the Netduino’s 3.3V output to control turning on and off a 9v supply.

It took me a while to figure out how this should be wired up, but after a lot of looking around I found some arduino examples. This one in particular was very helpful

My take away is that you should have your circuit set up like this. Effectively your transistor is blocking the current from going to ground until some input to the base is given from the Netduino.

Some notes on the switch: There is a formula for figuring out the value of the resistor going to base is, however it is outside the scope of this tutorial. I’ve just used 1k and it works fine. Also be sure to connect both the ground from your power, and the ground from your Netduino. For the longest time I didn’t have my Netduino grounded like in the images above and could not figure out why it was not working!

Netduino Pull up and Pull down Resistor

admin — Sun, 20 Feb 2011 19:12:54 +0000

The idea of a pull up and pull down resistor initially confused me. After reading around the web a bit I found a description that helped me. Pull up and pull down resistors are used when you have something on your board that is not connected between the Vcc and ground (this is also known as an open circuit). Say for example when we wire up a motion sensor to our circuit, there will be a period of time when it is an open circuit or open collector. Whilst something is not connected directly between Vcc and ground it is susceptible to external electrical noise – which means you might get random erratic readings. For this reason – we use the pull up or pull down resistor.

Pull Up Resistor Example on the Netduino

The pull up resistor will make the input read as high/Vcc and when triggered go low to 0/ground.

Pull Up – Not Connected

Here we have the input port d0 being pulled up to Vcc by the 10k resistor. If we didn’t have the resistor you might get the event handler being randomly fired by electric fluctuations in the circuit.

Pull Up – Connected

Now when we complete the circuit by connecting to ground, we will fire the event handler. Our pin was being held at Vcc (3.3v) and now will be pulled to ground (0v). So our second parameter in the event handler will read as a low of 0.

Pull Up – Source Code

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.NetduinoPlus;

namespace _3_Digital_Input
{
    public class Program
    {
        public static void Main()
        {
            InterruptPort input = new InterruptPort(Pins.GPIO_PIN_D0, true, Port.ResistorMode.PullUp, Port.InterruptMode.InterruptEdgeLow);
            input.OnInterrupt += new NativeEventHandler(input_OnInterrupt);

            Thread.Sleep(Timeout.Infinite);
        }

        static void input_OnInterrupt(uint data1, uint data2, DateTime time)
        {
            string s = "";
        }
    }
}

Pull Down Resistor Example on the Netduino

The pull down resistor will make the input read as 0. When it is triggered it will go high to Vcc (3.3v).

Pull Down – Not Connected

Here we now are connected via the 10k ohm resistor to ground, bringing the pin to 0v.

Pull Down – Connected

When I complete the circuit the event handler fires. The pin was being held at 0v and now has been pulled high to 3.3v. If you breakpoint on the event handler and inspect the second parameter (data2) you should see the value come in as 1.

Pull Down – Source Code

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.NetduinoPlus;

namespace _3_Digital_Input
{
    public class Program
    {
        public static void Main()
        {
            InterruptPort input = new InterruptPort(Pins.GPIO_PIN_D0, true, Port.ResistorMode.Disabled, Port.InterruptMode.InterruptEdgeHigh);
            input.OnInterrupt += new NativeEventHandler(input_OnInterrupt);

            Thread.Sleep(Timeout.Infinite);
        }

        static void input_OnInterrupt(uint data1, uint data2, DateTime time)
        {
            string s = "";
        }
    }
}

Side note: The Netduino does also have an inbuilt Pull up resistor that you can turn on and off by the software. This is an enumeration that you can see as one of the parameters when creating the interrupt port. I didn’t include it on this example, as I wanted to show mirror symmetry between the pull up and pull down circuits.

The Netduino does not have an inbuilt Pull down resistor. So you will always have to wire it like the example above.

Building a DIY Home Alarm Part 2 (Netduino Plus WebServer)

admin — Fri, 18 Feb 2011 16:01:58 +0000

For this second part in the series I wanted to prototype the network connectivity of the Netduino. Why? Because I want the alarm to message me some how if some one breaks in AND I want to be able to interact with it from my phone.

Prototype Features

Run a threaded web server, capable of returning 200 OK with the HTTP body of “Hello World”
Flash the onboard LED whenever the webserver services an inbound request
Trigger a sound (I’ll cover this sound in more detail later in my posts). I was using a transistor switch to trigger a 555 timer which makes a 3khz sound to the speaker

Approach

I started off using any old network cable to connect to the Netduino. After some thought and discussion on the NetDuino chat I realized I should be using a Crossover cable. Luckily I had one to hand. (Good thing I hoard my electronics stuff ). I made sure the network cable was connected before I turned the NetDuino on. I think I read somewhere that with certain versions of the flashed software, it can be troublesome connecting the network cable afterwards.

I discovered that the Netduino’s network configuration can be configured programatically or through the tool that comes with the microframework MFDeploy.exe (I found it in C:\Program Files (x86)\Microsoft .NET Micro Framework\v4.1\Tools). Through a lot of experimentation I figured the easiest way of me connecting the pc and the netduino would be to manually assign ip addresses on the same subnet mask. My laptop was initially setup for DHCP assigned ip on the physical network connection and the netduino was pre-wired with an ip. I set the pc to be a manually assigned IP of 10.5.0.1 and the netduino to 10.5.0.2 and both on a subnet mask of 255.0.0.0.

Using Fiddler I sent HTTP Get Requests to the web server and received 200 OK messages back with the content “Hello World”.

Demo

Source Code

Note: I used the .Net Micro Framework Networking Toolkit to run the web server.
PS: Make sure you use the assembles found in the folders prefixed with “Micro” as they are compiled for the micro framework.
PPS: I used port 8080 as my machine is running IIS on port 80.

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware;
using SecretLabs.NETMF.Hardware.NetduinoPlus;
using MFToolkit.Net.Web;
using Microsoft.SPOT.Net.NetworkInformation;

namespace WebServer
{
    public class Program
    {
        public static void Main()
        {
            HttpServer httpServer = new HttpServer(8080, new MyHttpHandler());
            httpServer.Start();
        }
    }

    public class MyHttpHandler : IHttpHandler
    {
        private OutputPort led = new OutputPort(Pins.ONBOARD_LED, false);
        private OutputPort sound = new OutputPort(Pins.GPIO_PIN_D5, false);
        private bool playSound = false;

        public void ProcessRequest(HttpContext context)
        {
            led.Write(true);
            BuildHttpResponse(context.Response);
            led.Write(false);

            if (playSound == false)
            {
                playSound = true;
            }
            else
            {
                playSound = false;
            }

            sound.Write(playSound);
        }

        public void BuildHttpResponse(HttpResponse httpResponse)
        {
            httpResponse.HttpStatus = HttpStatusCode.OK;
            httpResponse.WriteLine("Hello World");
        }
    }
}

Building a DIY Home Alarm Part 1 (Learning electronics)

admin — Tue, 15 Feb 2011 16:04:38 +0000

Background

After listening to Scott Hanselman’s podcast on the NetDuino I was really interested in the idea of building my own hobby projects and learning electronics. I’ve got two projects that I want to build, both of them rather ambitious

The first idea was to build a Snowbot (snow blowing robot) and the other idea was to build a home alarm system. I’m starting with the home alarm system as it in theory should be easier to build.

This is what I would ideally have in a home alarm system:

Networked, so that I can arm/disarm and check the status over the web
Email alerts
Sensors on all the doors and windows
2x Motion sensors (main floor and basement)
Bloody loud alarm system

Starting Point

So looking at the best places to start learning how to do all of this I decided it would be best to start learning electronics. The best resources I have found so far are:

allaboutcircuits.com – an education website about electronics
MAKE: Electronics the book (totally awesome)
MAKE: Magazine videos on youtube are really well done and entertaining

I tried using software to model circuits but found them really confusing. I tried Tina-TI, while it is really good for certain learning, I have found that actual hands on with components is easier to learn from.

I decided to buy some basic electronics components. Looking through the Make electronics book and searching on the web i found this product, a starter electronics kit for the first few chapters of the MAKE: Electronics book. I noted down what i thought were the key components and went to the local electronics shop and bought them for around $150 including digital multimeter.

The main components I bought were the multimeter, a $15 dollar pack of assorted resistors (definitely worth the money), various capacitors, some NPN transistors, breadboard and 9v supply, assorted LEDs and wires.

After reading up on DC theory at allaboutcircuits.com I started building some really simple circuits, with the home alarm system in mind.

I tried to visualize what components the alarm would need to have to make this alarm system. At its simplest it would need the following:

Blinking LED
Siren
Circuit that would break when a window/door was opened
Some sort of keypad interface (ideally touchscreen)
Netduino as the microcontroller

The next post in this series will cover the alarm’s blinking LED.

Sebastian Patten

Node.js sharing JavaScript code between client and server

Current state of affairs

Solution

Setting up the Server Side (Node.js)

Server Side Code – Server.js

Code that can live on client or server – Person.js

HTML Page

My Sample Project

JavaScript for the HTML Page – Main.js

More Reading

Tips For Writing Software And General Business Heuristics

Highlight the current line in Visual Studio 2010 with Resharper

Steps

Building a Website Like a Boss (Part 1)

Links to tutorial parts

Background

What The Architecture Offers

Sneak Peak/How Do We Do This?

Personal Goals for the Web Application

How to revise for MCTS 70-515 Web Applications with .NET 4.0

Difference between ASP.NET Data Controls

Single Item Display

FormView

DetailsView

Multiple Item Display

Repeater

ListView

DataList

GridView

Netduino Transistor Switch

Netduino Pull up and Pull down Resistor

Pull Up Resistor Example on the Netduino

Pull Up – Not Connected

Pull Up – Connected

Pull Up – Source Code

Pull Down Resistor Example on the Netduino

Pull Down – Not Connected

Pull Down – Connected

Pull Down – Source Code

Building a DIY Home Alarm Part 2 (Netduino Plus WebServer)

Prototype Features

Approach

Demo

Source Code

Building a DIY Home Alarm Part 1 (Learning electronics)

Background

Starting Point