Tag Archives: Arduino Gemma

Starduino is an 8-bit Super Mario tree topper

Bring this classic power-up to life as part of your Christmas decor. 

Super Stars (also referred to as Starmen) can be found in a plethora of Mario Bros. games, including the original and the Mario Kart series. One place you’d typically not find them, however, is on top of a Christmas tree. That was until now.


In the game, when a player gets a star, they become temporarily invulnerable to all damage. This enables them to defeat anything and rack up points, except to hazards that would normally be fatal regardless of power-ups. Well, John Edgar Park has decided to swap out invincibility for some sparkling decor.


The Super Mario fan has built his own 8-bit tree topper using an Arduino, LEDs and a few other off-the-shelf tools. Starduino — a name that was coined by yours truly — is a fairly straightforward project. It consists of an Arduino GEMMA (ATtiny85) that drives an Adafruit NeoPixel ring housed inside a 3D-printed blocky star. Meanwhile, power is supplied by a USB cable plugged either into a wall adapter or a battery.

Still looking for a last-minute focal piece for your tree? Don’t despair! Park has provided a step-by-step breakdown of his build on Adafruit, so you can spark some nostalgia of your own this holiday season.


These smart shoes will improve your morning jog

These Arduino Gemma-based sneakers will make your run more fun with less injuries! 

Like 75% of runners, Maker Lisa Kusaka is an avid jogger, but doesn’t enjoy it so much without her extensive playlist of music. One day, she noticed that certain songs seemed to suit her pace better than others, becoming a natural and entertaining pace keeper. With this in mind, RunBeat was born.


Developed while at SLEM (an international innovation and education institute for footwear located in the Netherlands), it is a smart insole that measures your running pace and generates music with the same beats per minute to match your stride. The system consists of a pressure sensor embedded into the insole beneath the ball of the foot to promote proper running form. The sensor reads the impact of each step and sends the data over to an Arduino Gemma (ATtiny85) located in the shoe’s arch.

This pace data is also transmitted to an accompanying mobile app via Bluetooth. This app then selects the tunes based on the preferred genre and the current running pace. What’s nice is that, since all of the technology is located in a 3D-printed insole and not the sneaker itself, RunBeat is compatible with just about every running shoe on the market.


On top of that, fellow SLEM classmate Chrissy Glove recently came up with an idea to improve the running experience as well. This time, instead of pairing beats to stride, the maker wanted to create a wearable device that would help improve form. Having dealt with injuries throughout her own career, she was well aware as to how imperative injury prevention is to any runner. So, she decided to develop a smart sneaker that would detect improper form in three ways: by recognizing when a runner’s gait differed from their norm, suggesting a forefoot foot strike and detecting the precise location of an injury when one strikes.


The aptly named Strike features a side lacing system to relieve pressure from the tendons on the top of the foot, while Adafruit NeoPixel lights allow for nighttime safety and easy notification. Glove attached an Velostat sensor in the heel pad to an Arduino Gemma (ATtiny85) and a piezo buzzer. These electronics, along with a battery, are all enclosed inside a 3D-printed insole.

The Maker wrote some code that would read the pressure sensor as input, and in turn produce a different effect with the LEDs and piezo buzzer accordingly. For example, when the runner strikes with their heel, they will feel a buzz to alert them so they can modify their footstrike to be more forefoot. Additionally, the shoe records the wearer’s normal foot strike pattern and stores it in its internal memory. This way, should the runner happen to stray away from his or her natural gait, they will be warned in similar fashion.


Beyond that, Glove included electrodes in the shoe that could read the nerve endings on the bottom of the runner’s foot. As a precaution should they get hurt, Strike can better determine the exact location of the injury by buzzing in a varying sequence and illuminating the red LEDs.

Arduino and Adafruit unveil the Arduino Gemma

During his Maker Faire Rome presentation, Arduino Co-Founder Massimo Banzi offered attendees a preview of the company’s new collaboration with Adafruit — the Arduino Gemma, a tiny wearable MCU board packed in a 1-inch (27mm) diameter package.


Similar to the original Adafruit Gemma, the mini yet powerful wearable platform board is powered by the versatile ATtiny85. The board will be default-supported in the Arduino IDE, equipped with an on/off switch and a microUSB connector. Since it is programmable with the Arduino IDE over USB, all Makers will have the ability to easily create wearable projects with all the advantages of being part of the Arduino family.


“We wanted to design a microcontroller board that was small enough to fit into any project, and low cost enough to use without hesitation,” Adafruit’s Limor Fried (aka LadyAda) explained in a blog post last September. “Gemma is perfect for when you don’t want to give up your Flora and aren’t willing to take apart the project you worked so hard to design. It’s our lowest-cost sewable controller.”

Ideal for small and simple projects sewn with conductive thread, the [tinyAVR based] Arduino Gemma fits the needs of nearly every entry-level wearable creations — ranging from reading sensors to driving addressable LED pixels.

To better visualize just how small we are talking, look at this image from an earlier version of the Adafruit Gemma.


“The ATtiny85 is a great processor because despite being so small, it has 8K of flash and 5 I/O pins, including analog inputs and PWM ‘analog’ outputs. It was designed with a USB bootloader so you can plug it into any computer and reprogram it over a USB port (it uses 2 of the 5 I/O pins, leaving you with 3),” Arduino noted in its announcement.

In addition to ATtiny85 MCU, other key hardware specs include:

  • Operating Voltage: 3.3V
  • Input Voltage (recommended): 4-16V via battery port
  • Input Voltage (limits): 3-18V
  • Digital I/O Pins: 3
  • PWM Channels: 2
  • Analog Input Channels: 1
  • DC Current per I/O Pin: 40 mA
  • DC Current for 3.3V Pin: 150 mA
  • Flash Memory: 8 KB (ATtiny85) of which 2.5 KB used by bootloader
  • SRAM: 0.5 KB (ATtiny85)
  • EEPROM: 0.5 KB (ATtiny85)
  • Clock Speed: 8 MHz
  • MicroUSB for USB Bootloader
  • JST 2-PH for external battery

For those seeking to use an Arduino Gemma in their next DIY wearable project, the board will be available for purchase on the Arduino Store and Adafruit Industries beginning late Fall 2014.