Tag Archives: microcontroller

KeKePad is an ATmega32U4-powered wearables platform

KeKePad is a plug-and-play platform that replaces conductive thread with tiny connectors and thin cables.

Like most Makers, Michael Yang enjoyed using the Arduino Lilypad for his wearable and e-textile projects. However, he discovered that conductive thread has a few drawbacks: it is expensive, it has no insulation and its resistance is quite high. Plus, in order to achieve a tight connection, the wires need to be soldered (which means that it becomes rather difficult to remove if there are any mistakes).


So, as any DIY spirited individual would do, he set out to solve this problem. The result? KeKePad, a new modular platform that’s 100% compatible with the Arduino LilyPad USB and can be programmed using the Arduino IDE. The board is based on the ATmega32U4 — the same chip that can be found at the heart of the wildly popular Adafruit FLORA — and features built-in USB support, so it can be easily connected to a PC. Like other wearable MCUs, the controller boasts a familiar round shape (which measures 50mm in diameter) along with 12 tiny three-pin Ke Connectors and 11 sew tab pins.


What really sets the platform apart, though, is its unique wiring and connection method. The KeKePad entails a series of small sewable modules that link together via the Ke Connectors and special cables, or Ke Cables, with crimp terminals. This eliminates the frustration often associated with using conductive thread. With a diameter of only 0.32mm, the wire is extremely flexible, super thin and coated in Teflon.


At the moment, there are approximately 20 different modules to choose from, including sensors for detecting light, UV, sound, barometric pressure, temperature, humidity, and acceleration, as well as actuator modules for things such as LEDs, MP3s, OLED displays and vibrating buzzers.

Intrigued? Head over to KeKePad’s Indiegogo campaign, where Yang and his team are currently seeking $2,000. Delivery is slated for April 2016.

Rewind: 50 boards you’ll want to know about from 2015

Here’s a look at a bunch of boards that caught our attention over the last 12 months. Feel free to share your favorites below! 

“Hardware becomes a piece of culture that anyone can build upon, like a poem or a song.” – Massimo Banzi

Arduino Zero


A 32-bit Arduino powered by the Atmel | SMART SAM D21.

Arduino Wi-Fi Shield 101


An IoT shield with CryptoAuthentication that enables you to wirelessly connect your Arduino or Genuino with ease.

Arduino MKR1000


A powerful board that combines the functionality of the Zero and the connectivity of the Wi-Fi Shield.

Atmel | SMART SAM L21


A game-changing family of Cortex-M0+ MCUs that deliver power consumption down to 35 µA/MHz in active mode and 200nA in sleep mode.



An ultra-low power Bluetooth Smart SoC with an integrated ARM Cortex-M0 MCU and transceiver.



An ARM Cortex-A5-based MPU that offers great features integrated into lower pin count packages, making it ideal for applications where security, power consumption and space constraints are key considerations.

Atmel | SMART SAM S70/E70


An ARM Cortex-M7-based MCU with a floating point unit (FPU) that’s ideal for connectivity and general purpose industrial applications.



A space-ready version of the popular ATmega128.

Adafruit Feather


A new line of development boards that, like it’s namesake, are thin, light and let your ideas fly. Expect Feather to become a new standard for portable MCU cores.

Adafruit METRO 328


An ATmega328-driven processor packed with plenty of GPIO, analog inputs, UART, SPI and I2C, timers, and PWM galore – just enough for most simple projects.

Arduino GEMMA


A miniature wearable board based on the ATtiny85.

Adafruit Bluefruit LE Micro


A board that rolls the versatility of the ATmega32U4 and the wireless connectivity of the SPI Bluefruit LE Friend all into one.

SparkFun Stepoko


An Arduino-compatible, 3-axis control solution that runs grbl software.

SparkFun SAM D21 Breakout


An Arduino-sized breakout for the ATSAMD21G18.

Bosch Sensortec BMF055


A compact 9-axis motion sensor, which incorporates an accelerometer, a gyroscope and a magnetometer along with an Atmel | SMART SAM D20 ARM Cortex M0+ core.

BNO055 Xplained Pro


A new extension board, which features a BNO055 intelligent 9-axis absolute orientation sensor, that connects directly to Atmel’s Xplained board making it ideal for prototyping projects for IoT apps.



A prototyping platform that combines SIGFOX, BLE, NFC, GPS and a suite of sensors. Essentially, it’s the Swiss Army knife for the IoT.

Qduino Mini


A tiny, Arduino-compatible board with a built-in battery connector and charger built-in, as well as a fuel gauge.

Tessel 2


A dev board with a SAM D21 coprocessor, reliable Wi-Fi, an Ethernet jack, two USB ports and a system that runs real Node.js/io.js.



A Windows 10 single-board computer equipped with an Intel Atom x5-Z8300 Cherry Trail processor, 2GB of RAM, 32GB of storage and an ATmega32U4 coprocessor.

LightBlue Bean+


An Arduino-compatible board that is programmed wirelessly using Bluetooth Low Energy.

Makey Makey GO


A thumbdrive-shaped device that can transform ordinary objects into touch pads.



An uber mini, DIY board based on an Atmel | SMART AT91SAM9N12 that runs Linux via a USB drive.



A set of tiny modular circuit boards that takes the hassle out of building electronics.

Microduino mCookie


A collection of small, magnetically stackable modules that can bring your LEGO projects to life.

The AirBoard


A compact, open source, wireless and power efficient dev board designed to learn, sketch and deploy prototypes out in the field.



A matchbox-sized, Arduino-compatible MCU powered by a small solar panel.



An integrated platform that brings the power of the cloud to the edge of the network, enabling you to observe, learn and capture actionable insights from existing physical ‘things’ in your environment.

Sense HAT


An add-on for the Raspberry Pi equipped with a gyroscope, an accelerometer, a magnetometer, a temperature sensor, a barometric pressure sensor and a humidity sensor, as well as a five-button joystick and an 8×8 RGB LED matrix — all powered by an LED driver chip and an ATtiny88 running custom firmware.



A HAT with an Arduino-compatible processor that responds quickly to real-time events, while letting the Raspberry Pi do all of the heavy lifting.



A cost-effective, Arduino-compatible board with built-in Wi-Fi.



A little board designed for wearable devices that features a BNO055, an ATmega328P and a CR2032 coin-cell battery.

 XeThru X2M200 and X2M300


A pair of adaptive smart sensor modules that can monitor human presence, respiration and other vital information.

LinkIt Smart 7688 Duo


An Arduino Yún-friendly platform powered by an ATmega32U4 and MediaTek MT7688 SoC.



A small, inexpensive controller with an embedded OLED display and Wi-Fi connectivity that you can program using existing tools like the Arduino IDE.



A next-generation, Arduino and Raspberry Pi-compatible dev kit for robotic motion structure systems and 3D printers that boasts an Atmel | SMART SAM D21 at its core.



A dedicated security peripheral for the Arduino and was made in collaboration with SparkFun’s previous hacker-in-residence, Josh Datko. This shield adds specialized ICs that perform various cryptographic operations which will allow you to add a hardware security layer to your Arduino project.



An add-on board that makes it easy to secure your Raspberry Pi and Linux applications.

Flip & Click


A two-sided, Arduino-like board with an AT91SAM3X8E for its heart.



An open source toolchain for embedded hardware security research including side-channel power analysis and glitching. The board uses a Spartan 6 LX9, along with a 105 MS/s ADC, low-noise amplifier, an Atmel | SMART SAM3U chip for high-speed USB communication, MOSFETs for glitch generation and an XMEGA128 as a target device.



An Arduino Leonardo-like board with built-in NFC that lets you replace your keys with any smartphone, NFC ring or proximity card.



An inexpensive, open source and shrunken-down version of the Arduino Zero that boasts a 32-bit ATSAMD21G18 running at 48MHz and packing 32K of RAM.



An open source, Arduino-compatible board with an ATmega32U4, ESP8266 Wi-Fi module and lithium-ion battery support.



An ATmega32U4-powered, 8-bit synthesizer that enables you to create NES, C64 and Amiga-style chiptune music by simply connecting a MIDI device.

Zodiac FX


An OpenFlow switch that is powerful enough to develop world-changing SDN apps yet small enough to sit on your desk. Based on an Atmel | SMART SAM4E, the unit includes four 10/100 Fast Ethernet ports with integrated magnetics and indicator LEDs along with a command line interface accessible via USB virtual serial port.

Goldilocks Analogue


A board that brings sophisticated analog and audio input, output and storage capabilities to the Arduino environment.



A super small and expandable IoT system for Makers.



A smart display that features an Atmel | SMART SAM D21 MCU operating at 48MHz and packing 32K of RAM, along with a 1.5” 128×128 pixel OLED screen and a microSD slot.



An Arduino crammed inside an SD card.

… and how could we not mention this?

The WTFDuino!


Do you feel like today’s MCUs are too simple and sensible? Well, one Maker decided to take a different approach by “undesigning” the Arduino into a banana-shaped processor whose form factor is impossible to breadboard and whose pins are incorrectly labelled.


UC San Diego engineers develop a smart mouth guard

Researchers have developed an integrated wireless mouth guard biosensor for real-time monitoring of health markers in saliva.

Engineers at the UC San Diego have developed a smart mouth guard capable of monitoring health markers, such as lactate, cortisol and uric acid, in saliva and transmitting the data wirelessly to a mobile device. The idea is that, one day, the technology could be used to keep tabs on patients without invasive procedures, as well as track athletes’ performance or stress levels in soldiers and pilots.


The study, which was led by UC San Diego professors Joseph Wang and Patrick Mercier, focused primarily on uric acid, which is a marker related to diabetes and gout. Currently, the only way to monitor these levels in a patient are through blood tests. Wang explains, “The ability to monitor continuously and non-invasively saliva biomarkers holds considerable promise for many biomedical and fitness applications.”

The team of researchers developed a screen-printed sensor using silver, Prussian blue ink and uricase. To ensure that the sensors only reacted with the uric acid, the nanoengineers had to set up the chemical equivalent of a two-step authentication system. The first step involves a series of chemical keyholes that allows only the smallest biochemicals to enter inside the sensor. The second step is a layer of uricase trapped in polymers. The reaction between acid and enzyme generates hydrogen peroxide, which is detected by the Prussian blue ink.

That information is then sent to a circuit board as electrical signals via metallic strips that are part of the sensor. The board, which is no much bigger than a penny, is equipped with a microcontroller, a Bluetooth Low Energy transceiver, and a potentiostat. These small chips detect the sensor output, digitizes it and wirelessly relays the data over to a smartphone or computer.

Thus far, the researchers have been able to show that the mouth guard sensor could offer an easy, more reliable way to monitor uric acid levels; however, it has only been tested with human saliva and not yet actually in a person’s mouth. Looking ahead, the team plans to embed all of the electronics inside the wearable device so that it can be worn. This process will entail testing the various sensors and electronic materials to ensure their biocompatibility.

The next iteration of the mouth guard is expected to be completed in a year or so. Until then, you can read all about the study in its recently published article in Biosensors and Bioelectronics.

(Image: UC San Diego, Jacobs School of Engineering)

Bluefruit LE Micro is a BLE board for Makers

Bluetooth Low Energy + ATmega32U4 = Bluefruit LE Micro 

Makers who are looking to create a Bluetooth-enabled project will be excited to learn of Adafruit’s latest product. The newly-unveiled Bluefruit LE Micro rolls the versatility of the ATmega32U4 MCU and the wireless connectivity of the SPI Bluefruit LE Friend all into one board.


What’s nice is that the Bluefruit LE Micro makes is easier than ever to add BLE capabilities to any number of DIY projects. Makers can program the ATmega32U4 over USB using its built-in USB bootloader, either directly with AVRDUDE or the Arduino IDE. The board runs at a 8MHz clock speed, boasts a logic level of 3.3V for compatibility with a wide range of sensors, and features more than 20 GPIO pins, including I2C, SPI, a UART and six analog inputs. On top of that, the chip packs 28KB of Flash, 2KB of RAM, and of course, native USB for programming and communication.

As Adafruit points out, Makers can add a rechargeable LiPo battery with the help of a LiPoly backpack as well. Simply solder it on top of the Bluefruit LE Micro and it’ll juice up the battery via the microUSB connector. When the USB is unplugged, it will run off the battery.

“The Bluefruit LE module is an nRF51822 chipset from Nordic, programmed with multi-function code that can do quite a lot! For most people, they’ll be very happy to use the standard Nordic UART RX/TX connection profile. In this profile, the Bluefruit acts as a data pipe, that can ‘transparently’ transmit back and forth from your iOS or Android device.”


“Thanks to an easy-to-learn AT command set, Makers will have total control over how the device behaves, including the ability to define and manipulate your own GATT Services and Characteristics, or change the way that the device advertises itself for other Bluetooth Low Energy devices to see. You can also use the AT commands to query the die temperature, check the battery voltage, and more, check the connection RSSI or MAC address, and tons more.”

Additionally, the Bluefruit app enables Makers to quickly prototype their projects by using their iOS or Android device as a controller. Adafruit has a color picker, a quaternion/accelerometer/gyro/magnetometer, an eight-button gamepad and a GPS locator. This data can be read over BLE and relayed to the on-board ATmega32U4 for processing.


Interested in this un-BLE-ievable board? Head over to Adafruit’s official page to order yours.

CMYK 4.0 is a smart, foldable electric bike for your morning commute

This smart electronic bike will let you know the fastest, easiest and safest way to work.

Are you among the millions of city dwellers that ride a bike to work in the morning? If you’re looking to make your commute from home to the office a bit more efficient, then CMYK 4.0 may be for you. Created by New York City-based startup Brooklyness, the foldable electronic bike will automatically reroute you should there be any construction, traffic jams or pothole-filled streets in your way.


The smart bike is packed with several features including advanced hardware and mobile integration. CYMK 4.0 is equipped with a gyroscope and an accelerometer to analyze the terrain and map the road, a cadence sensor to determine how fast you are pedaling and to adjust parameters for a smooth ride, a built-in heart rate monitor on its grips to track performance, and an Atmel MCU to process the information gathered by each of its sensors.

An accompanying app is tasked with crunching the collected data and displaying it on your smartphone over Bluetooth. What’s more, the e-bike boasts a phone charger directly on its handlebar so you can power your mobile device on-the-go, a 24V lithium battery, and a 250W motor that allows for 30 miles of assisted riding on a single charge.


Not only does the e-bike’s embedded sensors determine the condition of the road as you ride it, upon getting to their destination, the app will prompt you to answer a few questions about the traveled course. The more people riding, the more data that can be garnered to generate a map of the best routes to take. This can help you decide which way to go in order to avoid Greenwich Village’s cobblestones, for example.

Its app also enables you keep tabs on performance by measuring things like calories burned, average heart rate, and peaks and lows so you can target which areas of your daily commute to increase speed. Aside from your smartphone, a web-based dashboard lets you take a closer look at battery rate of discharge, charging time and how power consumption changes along your route. You can even plan your commute and socialize with other cyclists to organize a group ride or to receive helpful advice.


Designed with safety and security in mind, the CMYK 4.0 includes an electronic lock that will sound if the bike is ever moved, an RFID tag for easy locating, app-controlled headlights for visibility, and laser beams that project a virtual lane on the road. Beyond that, the two-wheeler is super portable, weighing just 25 pounds and can be folded up to make for easily carrying on public transit or stowing away at work.

Looking for a new means of transportation to work? Hurry over to CMYK’s Indiegogo page, where the Brooklyness team is currently seeking $30,000. However, you’ll have to wait until March 2016 for delivery.

The CryptoCape is the BeagleBone’s first dedicated security daughterboard

The CryptoCape extends the hardware cryptographic abilities of the BeagleBone Black.

With the insecurity of connected devices called into question time and time again, wouldn’t it be nice to take comfort in knowing that your latest IoT gadget was secure? A facet in which many Makers may overlook, Josh Datko recently sought out to find a better way to safeguard those designs, all without hindering the DIY spirit. The result? The CrytpoCape — which initially debuted on SparkFun last year — is a dedicated security daughterboard for the BeagleBone that easily adds encryption and authentication options to a project.

Generally speaking, cryptography offers a solution to a wide-range of problems such as authentication, confidentiality, integrity and non-repudiation, according to Datko. SparkFun notes that the $60 Atmel powered cape adds specialized ICs that perform various cryptographic operations, amplifying a critical hardware security layer to various BeagleBone projects.

The CyrptoCape is packed with hardware, including 256k EEPROM with a defaulted I2C address (plus write protection), a real-time clock (RTC) module, a Trusted Platform Module (TPM) for RSA encryption/decryption, an AES-128 encrypted EEPROM, an ATSHA204 CrypoAuthentication chip that performs SHA-256 and HMAC-25 and an Atmel ATECC108 tasked with the Elliptic Curve Digital Signature Algorithm (ECDSA).

“You will also find an Atmel ATmega328P microcontroller and a large prototyping area available on the board. The ATmega is loaded with the Arduino Pro Mini 3.3V bootloader and has broken out most of the signals to surrounding pads,” its SparkFun page reveals.

Beyond that, each easy-to-use CryptoCape comes with pre-soldered headers making this board ready to be attached to your BeagleBone right out of the box. The only additional item a Maker will need to get the CryptoCape fully-functional is a CR1225 coin-cell battery.

Interested? You can check out the product’s official SparkFun page here. Meanwhile, those looking to learn more should also pick up a copy of Datko’s book entitled “BeagleBone for Secret Agents.” The third chapter of the resource is devoted to the CryptoCape where Makers will learn how to combine a fingerprint sensor, the on-board ATmega328P, and the crypto chips to make a biometric authentication system.

Control your connected devices with augmented cords

Inspired by a water hose, MIT’s Tangible Media Group wants you to control connected devices with their cords.

It happens all the time: You reach into your bag, pocket or desk to pull out your headphones. And, no matter how neatly they were wrapped up beforehand, the cords are a tangled mess. Pair this with the rise of wireless technologies, and you can see why they’ve gotten a bad rap throughout the years. However, what if those cables were used as an interface with your connected devices? Imagine if such things as tying knots, stretching, pinching and kinking the wire could actually control the flow of data and/or power of your gadgets.


That’s what one joint research team, led by Philipp Schoessler of MIT’s Tangible Media Group and Sang-won Leigh of the Fluid Interfaces Group, has set out to do. Aptly called Cord UIs, it’s a project that wants to turn cords into a user interface and hopefully give them a meaning other than simply a nuisance.

“Cord UIs are sensorial augmented cords that allow for simple metaphor-rich interactions to interface with their connected devices. Cords offer a large underexplored space for interactions as well as unique properties and a diverse set of metaphors,” Leigh writes. “We also look at ways to use objects in combination with augmented cords to manipulate data or properties of a device. For instance, placing a clamp on a cable can obstruct the audio signal to the headphones. Using special materials such as piezo copolymer cables and stretchable cords we built five working prototypes to showcase the interactions.”

The Tangible Media Group’s latest paper explains that despite the intensive research on wireless technologies typically associated with the rise of the Internet of Things, cords aren’t going to entirely disappear for quite some time. In fact, those ubiquitous wires hold some unique properties, thereby making them an interesting and useful tangible interface. Among their most notable properties are their wide-range of materials and form factors, which range from flexible and spiral to flat and rigid. This enables them to potentially be employed to offload interactions from a device and to offer quick and eyes-free interactions.

“Moreover, one of the underlying principles of tangible interface design is to augment everyday objects with technology aimed at exploiting real-world metaphors. Most interactions we describe in this paper evolved from the idea to regard the cord as a water hose and data or power as water flowing in this water hose.”

The basis of the interactions stem strongly from the metaphor of looking at the cord as a hose, while the power and data are the liquid flowing through it. Furthermore, the researchers explored other analogies, such as “breaking a connection” and “pulling something out of something,” that create a strong conceptual model that would assist in making these interactions much relatable and easier to comprehend.

Subsequently, the team classified these cord actions into three categories: touch, knot and objects. In order to explore some of their proposed interactions, they devised five prototypes — each of which work by augmenting the entire or parts of a cord. The prototypes were all comprised of readily available materials, sensors and cables, while an Atmel based Arduino was used to program the cords and control the sensor readings.

Imagine if tightening a knot could dim a lamp; attaching a clip on a power cord could put a computer to sleep; squeezing a headphone cable could temporarily mute the earbuds; kinking a power strip’s cord could toggle it on/off; and, stretching a USB cord could safe-eject the hard drive. Here’s a look at the five different ways the researchers are looking to redefine those once “dumb” wires.



“To detect a knot in a cord, and use it to adjust the brightness of a lamp by altering its tightness, we embedded a Flexpoint 2.2-inch bend sensor into wrap-around isolation together with a four-strand cable. Two of the strands were used to read out the sensor data. The other two strands were used to power the lamp. We used the microcontroller to read out the analog resistance value and to control the brightness of the light accordingly.”



“We augmented a MacBook power cord with conductive polymer sandwiched between two sheets of heavy copper foil. When applying pressure the resistance between the two copper sheets decreases. Since the power cord doesn’t offer the possibility to send any signals to the laptop we decided to send a long pulse (1000ms) by switching the power cord on/off using a relay. Using AppleScript we listen for this rising-edge ‘signal’ by checking if the computer AC power is connected or not. We then issue the command to go to sleep or wake up.”



“We use conductive yarn that we wove into the fabric of braided cable sleeving. The microcontroller detects touch via a large resistor (~1 MOhm) placed in series, which responds to any resistance changes following contact with the human body and ground. It can also detect the amount of pressure that is applied to the cord, since the resistance is inversely correlated to the area of human skin touching the cord. By temporarily shorting ground to the microphone input on an audio cable we can toggle the pause/resume functionality in an iPhone. We chose to use capacitive sensing over pressure sensors to detect pinching, to avoid accidental triggering in through cable stress.”

Power Strips


“Alongside the power cord we placed a Piezo Copolymer Coaxial Cable from Measurement Specialties to detect kinks and switch on/off the power strip. The piezo polymer generates a voltage that is proportional to the amount of compression or stretch that is put on it. Piezo cables are often times used in traffic counting. To switch the power on/off we implemented a relay into a power strip that is controlled by a microcontroller.”

Hard Drives


“For the easy-eject hard drive we augmented a stretchable cord with a stretch sensor (resistive rubber) that decreases its resistance when expanded. We use a a special stretchable cord which is often used in robotics where it can help to reduce a lot of wear and tear caused by the moving robots. This cable can usually only be stretched up to 30% of its original length but by removing the curled strands from their original sleeving and threading it in rubber tubing we increased the stretch to more than 50%. To interpret a stretch and eject the hard drive we used openFrameworks in combination with AppleScript.”

The team notes that another potentially interesting area for further exploration is the actuation of cords. Meaning, Cord UIs could be used as output rather than only input, which would allow for ambient, audio, visual or haptic feedback about events or interactions. This project goes to show that there’s no reason these cables can’t become smarter, much like everything else these days. In fact, a majority of the interactions the team has suggested with Cord UIs would be inexpensive and easy for companies today to implement. Interested? You can read the entire research paper here.