The V-USB library is a pretty handy piece of code that lets you add USB connectivity to ATtiny microcontrollers (it was previously named tinyUSB). But if you’ve ever looked into adding the library to your own projects you may have been stymied by the complexity of the code. There are many examples, but there’s a lack of a concise quick-start for the uninitiated. [Joonas Pihlajamaa] has been working to correct that shortfall with his four-part V-USB tutorial series. It’s not for the absolute newbie; you should already be comfortable working with AVR chips but that’s the only real prerequisite we can see.

He starts the series with a look into the hardware considerations. USB provides a 5V power rail but the data lines expect 3.3V logic so this must be accounted for. With the test rig built on a breadboard he moves on to pick apart the code, covering various user-defined variables that you’ll need to set based on your project’s needs. We’re going to keep this on the back burner and hopefully the Troll Sniffing Rat will get a makeover (although we must say comments have been a lot nicer as of late… keep it up!).

We’ve embedded links to all four tutorial parts after the break.

• http://codeandlife.com/2012/01/22/avr-attiny-usb-tutorial-part-1/ (primer)
• http://codeandlife.com/2012/01/25/avr-attiny-usb-tutorial-part-2/ (hardware)
• http://codeandlife.com/2012/01/29/avr-attiny-usb-tutorial-part-3/ (software)
• http://codeandlife.com/2012/02/04/avr-attiny-usb-tutorial-part-4/ (wrapping up)

FPGAs are the bee’s knees. Instead of programming a chip by telling it what to do, FPGAs allow you to tell a chip what to be. Like everything though, a new skill set is needed to fully exploit the power of FPGAs. [Mike Field] decided to give back to the internet community at large and put up a crash course in FPGA design.

Right now, [Mike] has a couple of modules up that include subjects like binary math, busses, counting, and of course setting up the FPGA hardware. The recommended hardware is the Papilio One, although the Digilent Nexys2 is what [Mike] has been using so far.

We’ve seen a ton of awesome stuff that uses FPGAs, like the emulated Mac Plus, breaking HDCP, and an Ocarina of Time. [Mike]‘s tutorials look like a great starting point for some FPGA work. [Mike] is also looking for some feedback on his tutorials, so if you’ve got an idea of what he should cover be sure to drop him a line.

EDIT: The server was running on an FPGA and we can’t find a cache anywhere. If you’ve found a mirror, send a message. Apparently Amazon’s EC2 runs on an FPGA.

If you’ve been reading Hack a Day for long enough, you know about our infatuation with stepper motors. These precious little devices put the oomph into our CNC routers, 3D printers, robots, and other miscellaneous projects. Steppers aren’t your run-of-the-mill motors, though. [Steaky] posted a great introduction to stepper motors that lets you hit the ground running building any moving project you could imagine.

Apart from identifying a stepper and figuring out if it works, [Steaky] goes over how to make these motors turn. The theory behind an H-bridge is easy enough, but theory isn’t something often presented in schematics or stepper driver datasheets.

We’ve pulled more than our fair share of steppers from flatbed scanners and old printers. There’s nothing wrong with scavenging old parts, and whether you’re making a robot band to play your kid’s birthday party, robochess, or one of the many 3D printers or CNC machines, there’s going to be a stepper motor in your future.

OK, year-old pop culture references aside [Kyle] dropped us a line to show us his tutorial on using interrupts with your Arduino. Given the single core nature of your average Arduino’s AVR you pretty much have two choices for monitoring occasional un-timed inputs: Either check an input at an interval (which risks missing the signal entirely) or set up an interrupt to pause the chip’s normal operation. Obviously working with interrupts saves you tons of clock cycles since you are not polling a pin over and over. [Kyle] plans on a follow up tutorial to cover timer based interrupts, which can come in handy when generating frequencies and stuff.

Looking for more Arduino Basics? How about Basic on an Arduino. Check out our other beginner concepts posts as well if you need to work on your fundamentals.

This week’s video is the last in a series of videos where we show how to use Eagle CAD. Today we will look a the Layout portion of the program and will create a circuit board from the schematic that we created previously. We start by creating a layout file and then moving all of the parts to appropriate places on the circuit board. After that, [Jack] shows how to route the traces. Along the way, he talks about the tools that he is using and various ways to use them. The end result is a prototyping board for the PIC18F44J11.

Like the others, this video is fairly long at 29 minutes, so make sure to have some time dedicated towards watching it if you do.

In next week’s video, we will be showing this board as it arrived to us from a manufacturer and will do a tutorial on how to solder.

If you have missed our previous videos, you can find them here:

Schematic part I
Schematic and Custom part creation
CAM Processor

We have also created many supplemental videos explaining how to use many of the tools in the tool palettes. You can find them on our Youtube channel:

Check out the video after the break!

[Dino Segovis] wrote in to tell us about his “hack”, making an AB Audio Amplifier. The advantage of this particular amp is that the transistors never turn off, which would cause distortion. A full schematic is given in the article as well as a parts list. A complete “bill of materials” makes any circuit building project easier, especially for the beginner.

Although this is by no means a new circuit design, (a similar setup is used in car audio equipment) [Dino] does a great job of explaining how things work in the article itself and in the video after the break. He also gives some great tips about transferring your drawn circuit to a breadboard in a neat and organized way at around 5:00 in the video.

[Dino] tries to come up with something like this every week, so be sure to check back on his aptly-named site, Hackaweek.com for more fun stuff like this. Also, he mentions using the “free music archive” for his videos. This looks like a good resource for those that want to make other videos like this and need some music that legally doesn’t have to be paid for.

[Chris] writes in to let us know about his latest animatronics tutorial, this time on robotic eyebrows! The tutorial takes us through the process of using a fairly simple PIC  circuit to display various facial expressions. Since a wide array of facial expressions have unique and well understood eyebrow positions this simple hack can make even the most bland looking mask come to life . Animatronics is a subject near and dear to our hearts, but the simple actuation of servos can go much further than cardboard faces. This easy to follow tutorial can help you on your way to controlling all sorts of servo stuff like vent flaps or um…  fish, if you’d like. The software is not very deeply explained but it is commented and available for download from [Chris]‘s site.

From here [Chris] plans to expand the project with more tutorials that can help further animate the face. We are particularly interested in the one and two eye systems he mentions, as well as more complicated eyebrow mechanics. Also check out [Chris]‘s other servo based robotics tutorials like the Sharpie Spotifier and the Wooden Menace.

There is also a video of the eyebrows in action after the break.

Interrupts are the name of the game for more functional microcontroller firmware. [Rajendra] just posted a tutorial covering all of the interrupt types for the PIC 16F688 microcontroller. He gives an overview of all of the major points: what an interrupt is, what causes interrupts, how to read the datasheet (often overlooked) to set up interrupts, and finally he applies it to a test platform and a bit of code.

We’ve been playing around with an Arduino again over the weekend and are a bit frustrated with the restricted access to interrupts. That issue deals with AVR interrupts, a topic with which we’re already well acquainted. But we work with PIC hardware much less often and it’s fun to explore how the other half does things, both in hardware and in code.

There is a plethora of electronics tutorials scattered about online. Sometimes it can be hard to separate the good ones from the bad, and the enlightening from the misinformed. We recently came across a pair that we found helpful, and thought they would appeal to anyone starting off in electronics.

In this video tutorial, [Dave Jones] at the EEVblog covers soldering, detailing good practices and common mistakes to avoid when working with through-hole components. As the second video in a series he picks up where part one left off, excitedly demonstrating the ins and outs of good soldering skills.

Hackaday reader [grenadier] is working on a series of beginner’s electronics tutorials, and this week’s entry covers wiring. He discusses wire types, gauges, and even provides a nifty self-computing chart that calculates power loss based on the length and gauge of the selected wire. Before wrapping things up, he briefly touches on fuses and the pitfalls of choosing wire that’s not up to the task at hand. While you’re over there looking over his tutorial, be sure to check out the Junkbox, there’s plenty of awesome stuff to be had!

Those following the ProtoStack tutorials will be happy to hear that there is a new installment which explains Pulse Width Modulation. If you’ve never heard of PWM before, it’s a method of generating a signal that is logic 1 for a portion of the time and logic 0 for the remainder of the time. It is the most commonly used method for dimming an LED, and that’s [Daniel's] example in this tutorial. But you’ll also find it used in many other applications such as servo motor control and piezo speaker control.

[Daniel] starts off with a brief explanation of duty cycle, then moves on to some examples of hardware and software PWM. Many of the AVR microcontrollers have a hardware PWM feature that allows you to configure a pin that toggles based on a target timer value. This is demonstrated using an ATmega168, but a method of using interrupts and your own code is also covered in case you don’t have a hardware PWM pin available.

[Rajendra Bhatt] wrote in to share a tutorial he put together demonstrating the basics of using LED dot matrix displays. While this subject might be old hat to many out there, his helpful walkthroughs are geared more towards beginners who are exploring various electronics concepts for the first time.

He explains the theory behind LED displays using a PIC-driven 5×7 matrix as an example. He discusses persistence of vision and how tricking the human eye can save you quite a bit of time and a whole lot of pins. Multiplexing is broken down into its most basic steps, which [Rajendra] illustrates by showing how a letter would be drawn on the LED display one column at a time. The use of a ULN2803A Darlington Array is also discussed, and he details why it is used when pulling the five columns of LEDs to ground.

The only portion of the tutorial we thought could be expanded upon was the programming section. While he does show how each letter of the alphabet can be displayed via a series of five hex values, he does not cover the “why” part of the process. Obviously while anyone familiar with binary and hex can figure it out in pretty short order, we think that it would be a great place to pause and expand the readers’ knowledge even more.

Overall it’s a useful tutorial, and most beginners would likely find it quite helpful.

This video falls under the category of things we want to send people when they ask “how do I get started with electronics”, and we get asked that a lot. For those of you who have been working with electronics for years at all, you can skip this entire video. That is, unless you really want to watch an instructional video on multimeters. In the video, which we’ve included after the break, they talk about the differences between different meters, the common uses and how to actually use the meter to get the results you need. Stuffed full of useful information, this video will get those of you who are still reading up to snuff pretty quickly. Now go use your multimeter to do some hacking!

[Adam] over at lifehacker is putting together a series on the principles of programming called “Learn to code”. They are using Javascript as a basis to teach the fundamentals that would allow you to get stuff done in any similar language, like actionscript. After you’ve got these basics down, even moving to an object oriented language shouldn’t be too difficult. We absolutely love educational resources and hope they continue this series pretty far. They’ve already released part one and part two. We have supplied the video from each after the break, but there’s more info at the links.

[Ladyada] is working on a tutorial series covering power supplies. If you’ve ever built an electronic project you’ve used some type of power supply but we think that most people have no idea how you get from mains power to the DC voltages that most small projects use. So if you want to learn, get started with the first installment which covers AC/DC converters based on a transformer like the one seen above.

These transformers are inside the heavy and hot wall-wart plugs that come with many electronics. We used one along with a breadboard power supply when building the pumpkin LED matrix. They use a pair of coils to step down the voltage to a much smaller level. From there it’s a matter of rectifying the AC into DC power, which she talks about in an easy to follow discussion.

We understand this type of converter quite well but we’re a bit foggy on switch-mode AC/DC converters that don’t use a transformer. They’re much better because you don’t have to build a regulator into the target project like you do with wall-warts. Can’t wait until she gets to that part of the series!

In this tutorial we are going to get up close with the Visual Studio 2010 environment. We will learn how to make a console application as well as a form to display our hello world applications.  This will give us an opportunity to view 2 types of solutions of the many available in Visual Studio.  We will start making the console application first then progress to the forms application.

First we must  understand the development environment we are going to use.  On the far left side is the toolbox panel.  This panel gives us access to a lot of controls  that can be used by the Windows Forms.  Next is the Solution Explorer that will allow us to navigate the projects and files we are going to create in this Solution.  The Properties panel is directly under my Solution Explorer and will allow us to change properties of controls and of the form we will create later on.  If any of these are not being displayed they can be retrieved from the View menu at the top under Other Windows.  For more information on the Visual Studio IDE visit MSDN and search for the specific questions you are having.

Then we need to start the Visual Studio environment and create a new project.  To do this we will go to File then navigate to New Project and click it.  A dialog box will appear and ask you which project you would like to include in your solution that will be automatically created for your project.  We need to use the Console Application.  Next we need to replace the box at the bottom where it says ConsoleApplication1 with HelloWorldConsole and then after the project and solution is created press CTRL-S to change the name of the solution file to HelloWorld in the box under the project name box and press OK.  This will create a project inside a Solution file. The solution file acts like the glue that binds all projects included in the solution file together.  Later on we will discover how this is beneficial for creating projects and making class files that reference DLL’s that we will code.

Once the project is created we are going to edit the program.cs file.  After you have open the program.cs we are going to add the text necessary to have the program output “Hello World” to the console.  To do this we will need to add the line Console.Out.WriteLine(“Hello World!”); inside the static void main curly brackets.  After this is complete we can now build and attempt to build our solution.  To build the solution we need to press CTRL + SHIFT + B and the build process will being.  After the build is a success we can now run the Console Application by pressing CTRL + F5. This will display a command prompt with “Hello World!”.

Here is the source code for program.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace HelloWorldConsole
{
class Program
{
static void Main(string[] args)
{
Console.Out.WriteLine("Hello World!");
}
}
}

We can now move on to the windows forms application of Hello World.  To do this, we need to go to the solution and Right Click, then go to Add then click New Project.  For the project we will name it HelloWorldForms.  After the project is created we are going to delete the Form1.cs and we are going to create a new form by Right Clicking the HelloWorldForms Project, Navigating to Add then to New Item,  and when the dialog box appears we are going to pick Windows Form.

The name we are going to use is main.cs and press Add.  We now edit the program.cs to change the Form1 that can be found in the file to main.  After the Windows Form is created we can start adding in Controls from the Toolbox.
We are going to drag a label and a button onto the form portrayed in the middle of the program.  We are going to edit the properties here to make the text inside the label blank and the name of the label lbHelloWorld instead of label1.  After this is done we are going to want to edit the button we dropped onto the form earlier.  We will change the name of the button to btnHelloWorld and the Text of the button to Click Me!.  After this is done we are going to want to use an event handler to tie the button and the label together, so when the button is clicked “Hello World!” will appear in the label.

To make an event handler for the button we are going to go to the Properties panel and click the button on the top that looks like a lightning bolt.  This will take us to all o the event handlers that this button can handle.  We want the Click event handler, this will create the code required to handle a click event in the main.cs.  Now that the wrapper is there we can code the output to the label when the button is clicked.  Inside the curly brackets of “private void btnHelloWorld_Click” in main.cs input the following line of code to link the two Controls:

lbHelloWorld.Text = “Hello World!”;

This will make the main.cs look like this:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace HelloWorldForms
{
 public partial class main : Form
 {
 public main()
 {
 InitializeComponent();
 }

 private void btnHelloWorld_Click(object sender, EventArgs e)
 {
 lbHelloWorld.Text = "Hello World!";
 }
 }
}

The program.cs should look like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace HelloWorldForms
{
 static class Program
 {
 /// <summary>
 /// The main entry point for the application.
 /// </summary>
 [STAThread]
 static void Main()
 {
 Application.EnableVisualStyles();
 Application.SetCompatibleTextRenderingDefault(false);
 Application.Run(new main());
 }
 }
}

After all of this is completed we need to run the program by pressing CTRL + F5 again. The screen that should appear should be something like this:

The screen after the button has been pressed should look like this:

Now that we have completed the next tutorial you should be able to move through the Visual Studio IDE to make multiple projects under one solution, delete files within a project and create new forms and classes, and modify source code within event handlers.  The next tutorial will go more in depth with the Visual Studio Toolbox and make a form with controls on it with minimal backbone code, as well as review some of the common files created and what is automatically included for you.  For more information on Toolbox Controls you can check out Microsoft MSDN article on Toolbox Controls. If you are having any trouble with this project feel free to comment and I will help to try and resolve the issue.  Until next tutorial, Happy Hacking!