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)

[Joel] of [Helion Microsystems] is at it again with his USB controlled solder reflow oven.  You may remember him from his crazy twitter-enabled Ewok model. Although these two projects are quite different, they both use the HU-320 USB breakout board that he’s in the process of getting funding for via [Pozible], or Australian Kickstarter for Yanks.

The reflow oven works using a thermocouple-enabled RS-232 voltmeter to output the temperature to the HU-320 board. [Joel] has been nice enough to provide us with the C# code to interface with many multimeters if you want to implement a similar project.  Temperature is controlled with a mechanical relay for what would appear to be a poor man’s PID controller.

Sadly, Fluke meters don’t seem to be listed, but your place of work probably wants their meter back anyway!  For another toaster reflow oven implementation, check out this [HAD] article.  Be sure to check out the video after the break for a video of the setup! (heat treat engineers may find the “recipe” format humorous).

Let’s get this straight, [Alex] is going to show us how to make controllers like this one? Where do we sign up? Even without seeing it in action we want one, but the urge to build is even greater after he shows it off (check the clip after the break). He’s a design student who made an open source project aimed at making it easier to build hardware controllers that pair with just about any software application.

The need for external controllers is on the rise, starting with music-based applications like DJ tools, and Midi controllers for musicians (we’re thinking Monome clones). But anything that can take input from a USB HID can be controlled with something like this. That’s because [Alex] is using the Teensy controller board as an interface. Just select the input types you want – sliders, potentiometers, buttons, switches – then wire them up to the microcontroller pins. If you start to run out of inputs he also discusses some add-on chips to use as port expanders.

Of course there’s a lot to be said for the physical appearance as well. Even though he used point-to-point connections for all of the controls, that wiring is hidden behind the aesthetically pleasing laser-cut dashboard. Follow his advice for layout and find a friend with access to a sweet laser cutter and you’re in business.

As masters of technology, our desks are often cluttered with odds and ends. We have cables spewing out of every nook, and our computer ports full. The last thing we really want is more stuff getting in the way or buried under piles of technical documentation when adding something like a USB hub. That is where [Michael] comes in, shoving a small USB hub into his Logitech keyboard.

The keyboard is already USB, and the hub has 3 forward facing ports and a fourth single port in the rear. Taking the 2 devices apart he used the already there USB cord from the keyboard replacing the input cord of the hub. Then he removed the rear port and directly wired his keyboard onto the hub.

From there, its just a matter of figuring out where he wanted the hub, and cutting out the plastic. He used a knife, and had fond memories of some minor cuts, which leads us to recommend being (more) careful. A little application of fire to blade goes a long way.

Once the keyboard is back together he has a convenient 3 port hub on the back of his keyboard that looks factory and saves clutter.

Behold this ATtiny85 based EEPROM programmer. It seems like a roundabout way of doing things, but [Quinn Dunki] wanted to build to her specifications using tools she had on hand. What she came up with is an ATtinyISP USB programmer, pushing data to an ATtiny85, which then programs an EEPROM chip with said data.

The hardware is the next module for her Veronica 6502 computer build. When we last saw that project [Quinn] was planning to add persistent storage for the operating firmware. This will be in the form of an EEPROM programmed with this device. Using ISP and an ATtiny as a go-between means that she should have no problems reflashing the OS without removing the chip. But it all depends on how she designs the interface.

For example, she blew a whole bunch of time troubleshooting the device because garbage data was being written to the chip. In the end, having her manual bus programmer hooked up during the flashing operation was the culprit. Lesson learned, it’s onward and upward with the build.

We’ve been featuring [Quinn's] projects a lot lately. That’s in part because they’re really interesting, but also because she does such a great job of documenting her experience.

[Mike] picked up a cheap USB hub for four pounds (about $6) including delivery. He wanted to know how it’s possible to get quality electronics for that price, and as you may have guessed it’s not possible. He cracked open the power supply that shipped with the hub and hooked it up for some testing.

The wall wart has a sticker on it that claims a rating of 1 Amp at 5 volts. It’s pretty easy to see that this hardware cannot meet that spec just by looking at the circuit board. It’s a low-end single sided board that has some really disappointing isolation between the mains and regulated side of the circuit. As far as we can tell there’s really no reliable regulation circuit on the low side of the transformer, and the tests that [Mike] runs in the clip after the break show this. From left to right in the picture above you can see voltage at the hub-side of the power cord, current on the load, and voltage leaving the circuit board. At just 560 mA the voltage the USB hub is receiving has fallen below 3 volts!

The link to this project was sent in by [Paul] after reading about that fake Canon camera PSU. We love this kind of stuff so keep the tips coming as you find them!

Tweet Receiving, that is. This Ewok model, named “Ewen the Cheerlight,” is able to rotate its head left and right as well as show expressions. The most interesting feature of this hack, however, is that the little Ewok actually wakes up each time one tweets a “colour” to @cheerlights and lets it’s owner [Joel] know what he thinks of the “color” you’ve chosen. [Joel] insists that he’s like this featured on [HAD], although it remains to be seen if it will soon be turned off after the tweets start rolling in…

As far as how the device works, the head is turned with a simple hobby servo motor, and the expressions are shown on a LED matrix. The model itself is built from a polystyrene ball and an old table lamp. The build really looks awesome.

All of this is controlled by an Easy USB Interface Board which is listed on [Pozible], the Australian version of [Kickstarter]. Be sure to check out the video of “Ewen” in action after the break!

This dorm room is ready to entertain, thanks in part to the LED wall sconces that [Joseph] hacked together. Inside each fixture you’ll find three 3-Watt LED modules. For proper heat dissipation he mounted them on sheet metal which he cut out, including some fingers for additional surface area. The shape for the heat sink was chosen to fit behind the diffuser of the sconce, which is an incandescent light fixture with the socket removed.

[Joseph] designed his own control boards for the base station and LED modules. They communicate with each other via RS485, which lets him run CAT-5 cable to each, but the lights do require external power as well. The controller itself is a USB dongle which takes the serial commands from a computer and pushes them out over the RS485 protocol. In the video after the break you can get a good look at the hardware and the overall performance of the system.

[Eric Gregori] had an OWI535 toy robotic arm. Although cheap (coming it at around $30) the arm is only set up to be used via a wired control box. [Eric] knew he could do better by adding computer control via a TI Launchpad and motor driver peripheral.

The arm has shoulder, elbow, and wrist joints, a rotating base, and a gripper. All of these are actuated by 3V DC motors and have just two control wires. [Eric's] motor driver add-on for the Launchpad works great in this case. It’s got three FAN8200 dual motor driver chips on board so it can control up to six motors. Once he made the hardware connections it’s just a matter of sending the commands to the Launchpad via its USB interface, but you will also need to use a larger microcontroller than comes with the Launchpad. Here he’s chosen an MSP430G2553.

In order to make things a little bit more fun he also wrote a GUI for controlling the arm from the computer. He used RobotSee, a programming language that lets you use an image of the hardware, and overlay the controls on top of it. Now he just needs to make this into a web interface and he can have a smartphone controlled crane game.

Don’t forget to check out the video after the break.

We love looking in on [Simon Inns'] projects, and this must be one of his very best. This is the fifth version of his MIDI-capable stylophone. The gist of the control system is that a conductive keyboard (made of a tinned PCB) is played by making a connection with the tip of a wired stylus — hence the name. The idea comes from the original 1968 Dubreq Stylophone hardware, but [Simon's] not just using the idea. He has his own working original and used it to reverse engineer the circuit design.

When it first came out, the Stylophone had three flavors for Bass, Standard, and Treble audio ranges. They differed only in the choices of passive components used in the circuit. [Simon] built the variations into his design so that they are selectable on one unit. This most recent version connects via USB, allowing you to control MIDI software. But unlike his first four iterations, this also offers MIDI-In capabilities. This makes it possible to control tuning, vibrato, and to drive the Stylophone circuitry from the computer interface. Get a good look at that, and a nostalgic Portal moment, by watching the clip after the break.

If you’re looking for an easier build, you might try this analog standalone version of the Stylophone.

[Oliver] had an old NES controller laying around, and without any other use for it, he decided to repurpose it as a portable storage device.

He gutted most of the controller, removing the plastic standoffs, leaving the D-pad and remaining buttons intact. He crammed a 32 GB flash drive inside, along with the guts from an SD card reader. Using a Dremel he cut several openings into the controller, one for the flash drive and SD card reader’s USB ports, as well as for the SD card itself. When the physical modifications were finished, he installed a small Linux distro on the flash drive, which can be run by any PC that supports booting from USB.

While some might argue, we think it’s a neat way to reuse an old gaming peripheral that he might have otherwise thrown out. The portable OS is something that would certainly come in handy, though we can’t wait until the Raspberry Pi is finished – it would be awesome to have a complete computer packed in there too.

Looks like the Lightweight USB Framework for AVRs (LUFA) has just been ported for ARM microcontrollers. NXP recently released a package for their LPC Cortex M3 family of ARM controllers. You won’t find a reference to LUFA on their nxpUSBlib description page (which we think is kind of sad), but if you grab a copy of the beta code the Version.h header file shows that it is indeed a port of the project. This is further backed up by the LUFA creator, [Dean Camera], who consulted with the NXP team doing the work.

The package provides an open-source USB stack that you can use in your projects as a USB host or USB device. We’re advocates of open source packages like this one as it makes it much easier for hobbyists to get help using the tools, and it allows the community to give back through bug fixes and feature additions.

We’ve highlighted a few LUFA projects, like this keyboard remapper and this AVR programmer. We’re looking to seeing the first set of NXP LUFA projects roll through!

[Thanks Johnny]

[Irongeek] is up to his old tricks once again with this new key logger prototype. It’s in the early stages, as attested by the breadboard built circuit, but [Adrian] still gives us a demo video after the break showing where he’s at right now. It comes in two flavors, the USB pass through seen above, or another that still connects to the computer via USB but functions with a PS/2 keyboard.

Aside from the obvious issue of a key logger stealing everything you type, there’s some prank value in this device too. The Teensy has more than enough processing power to watch what you typing and make changes as it goes. He shows off blatant rewrites, like changing “has” to “haz” or “you” to “U”. We think it would be better to change things like “they’re” to “their” or “it’s” to “its”. These would be very difficult to see happening and if you added randomness to how often the replacements occur, your victim would sooner come to the conclusion that they’re going crazy than that they’re the target of a little hazing. In fact, that’s probably the reason for our own grammar errors though the years; blast!

The advent of integrated USB peripherals in microprocessors (PIC, AVR, etc.) has certainly taken a lot of the work out of developing USB devices, not to mention reducing the silicon parts in these designs. But do you know what you’re doing when it comes to controlling them with user-friendly applications? [Simon Inns] is lending a hand with this in his recent tutorial. He shows how to use USB capable AVR chips along with your own Windows applications.

After the break you can see the video from which the above screenshot was captured. That’s a development board of his own making which hosts an ATmega32U4, as well as a USB-B port, LEDs, potentiometer, and a few switches. Taking a closer look, we love the breadboard friendly headers he used on the bottom of the board to break out all of the pins.

His demo shows the Windows app turning LEDs on the board on and off, as well as ADC data displaying the current potentiometer position with the onscreen dial. His code package includes the hardware design, firmware, and app software needed to follow along with what he’s doing.

[Cosimo Orlando] has a Motorola Xoom tablet. It’s an Android device that works great as a tablet, but can double as a Laptop when you need it to by adding a keyboard. The problem he was having is that the USB On-The-Go cables that he tried were never the right size or orientation. So he scavenged them for parts and built his own flat cable for a custom fit.

The final product pictured here actually uses protoboard to give the body some strength. [Cosimo] first laid out the dimensions on the substrate using a felt-tipped pen. He then took connectors from his mis-sized commercial cables and affixed them to the board with a combination of hot glue and solder. From there, just connect the five data lines and ground with some jumper wire and test for continuity. He finished this off with what he calls ‘adhesive plastic glossy black’ shaped to make a decent looking case. If you have any idea what product was used here, let us know by leaving a comment.