Video: The Google Authenticator-Arduino-LEGO mashup

Last week, Bits & Pieces took a closer look at an Arduino-powered Gmail (alert) lamp programmed to ping its creator in real-time about incoming emails labelled “important.” And today we’re going to get up close and personal with another Arduino-based project that involves a Google app known as Authenticator.

Essentially, Google’s Authenticator is a program that generates one time passwords (OTPs) for users, which are then employed as a second factor of authentication in conjunction with a “normal” password.

“OTPs work by having a shared secret and a synchronized clock on two devices,” HackADay’s Eric Evenchick explained. “When you generate the password, a hash based on the secret and timestamp is created. This proves that you have access to the secret, and can only be used once.”

As you can see in the video above (Note: hit the CC button for English captions), a Maker by the name of Luca Dentella designed a functioning authentication system using Google Authenticator and his Atmel-powered Arduino. The platform is showcased using a cute mini LEGO of a model house, complete with a door that swings open when the correct code sequence is entered.

“A web app is used to generate a secret that can be configured into the Arduino using an array, and into Google Authenticator using a QR code,” Evenchick added. “The Arduino is using a library that implements Time-based One Time Password authentication (TOTP).”

Interested in learning more about Luca Dentella’s Google Authenticator-Arduino-LEGO mashup? Be sure to check out his official project page here.

Arduino’s Yún powers this Gmail (alert) lamp

The Atmel-powered Arduino Yún may have only begun shipping this week, but eager Makers like Stefano Guglielmetti have already begun using the board in various DIY projects. Specifically, Guglielmetti built a Gmail (alert) lamp programmed to ping him in real-time about incoming emails labelled “important.”

“I need to be alerted in real time when I receive some important emails. Not all the emails –  we provide customer care for many clients, with different SLAs, and I need to be alerted only for the most important ones,” Guglielmetti wrote in an official Arduino blog post. “Moreover, sometimes I look forward to receiving a [specific] email, [so] I need something flexible, eye catching, that doesn’t depend on my computer or my cellphone.”

According to Guglielmetti, the working principle behind the DIY project is really quite straightforward.

“On Gmail, I defined a new label, so I can quickly change the rules for the messages that will go under it, then I tell to Arduino Yún which label to watch for (via REST APIs… amazing) and that’s it,” he explained. “The lamp – actually only just an LED [for now] – turns on every time I get new messages under that label. It’s the bat-signal principle!”

In terms of the code, Guglielmetti says he leveraged a number of new features unique to the Yún.

“In a single day I learned how to use the Bridge library to get data from REST webservices, how to save and load data from the Linux filesystem, and how to run processes on the Linux side and get the STDOUT results,” Guglielmetti added. “Now I will build the actual lamp, improving both the hardware and software.”

Additional information about the Gmail lamp project can be found here.

As previously discussed on Bits & Pieces, the Yún – designed in collaboration with Dog Hunter – is based on Atmel’s ATMega32u4 microcontroller (MCU) and also features the Atheros AR9331, an SoC running Linino, a customized version of OpenWRT. The Yún is somewhat unique in the Arduino lineup, as it boasts a lightweight Linux distribution to complement the traditional microcontroller (MCU) interface.

The Atmel-powered Arduino Yún can be snapped up for $69, or €52.