IoT DIY with Bluetooth Low Energy and Arduino

February 1, 2015 OpenSystems Media

Connecting yourself into the Internet of Things (IoT) is becoming increasingly accessible as DIY platform features and capabilities expand. DIY board and peripheral developers are coming out with more connected products all the time. Bluetooth Smart is one connectivity technology that shows a lot of promise for the IoT and small, low-power maker projects – plus the ubiquity of Bluetooth-enabled devices doesn't hurt.

Bluetooth Low Energy (BLE) includes additional functionality on a Classic Bluetooth controller, including lower power consumption, AES-128 encryption using CCM for strong packet encryption and authentication, and extended range from 30 feet to 200 feet – good for home-wide automation and sensing projects.

RedBearLab (www.redbearlab.com) is a maker board company who was an early adopter to BLE on maker platforms, specifically Arduino. The company focuses on IoT applications with special interests in embedded to mobile/portable devices and embedded to embedded technologies utilizing BLE and/or Wi-Fi. In 2012 they launched their first BLE shield for Arduino.

"At the time, there was a lot of interest in trying out the latest Bluetooth technology, but no 'user-friendly' development option was available – most of the BLE development tools still required very low-level embedded programming skills," says Ma Chi Hung, CEO at RedBearLab.

For Apple product support, BLE was a great addition to a maker's connected device development options.

"Before the launch of BLE, developing hardware that could work with iOS was limited to Apple's Made for iPod (MFi) licensees," Ma says. "Although you could use Wi-Fi instead of BLE, BLE is cheaper and more power efficient."

The biggest advantages of BLE are its low energy consumption compared to Wi-Fi, and its better mobile device and PC support compared to ZigBee, Ma says.

BLE does have some drawbacks as well: Support on Android and other mobile and desktop OSs are still under development, Ma says, among other issues. For example, before BLE v4.2, BLE couldn't connect to TCP/IP networking directly, limiting its IoT usefulness. Even though that issue has been addressed, it'll take time for the specification to become widely adopted.

"Bluetooth Low Energy was only introduced in 2010 – it is still evolving; it took classic Bluetooth more than 10 years before it became stable and mature," Ma says.

In all, BLE excels at certain applications and struggles with others. RedBearLab sees a mix of all existing and upcoming connectivity technologies being the most useful in the future IoT space.

As for Arduino as an IoT platform, RedBearLab finds it to be a user-friendly, widely used platform.

"A lot of existing users are familiar with Arduino and there is a big community of Arduino users sharing their BLE projects online," Ma says.

Arduino boards will celebrate their 10th year in 2015 – plenty of time to build a strong community and project resources. On the arduino.cc forums, "Home Automation and Networked Objects" is one of the largest topical boards (second to robotics at the time of posting – it's hard to beat robots in project coolness), not to mention the various other communities that focus on the platform.

However, Ma says the Arduino's Atmel MCU could cause some scalability issues for BLE projects – running the library for BLE on the Arduino takes up a lot of resources quickly. Arduino can also be less than ideal for low power processing as it lacks a stand-by mode, but this could be addressed in future board versions.

Developing firmware can be a challenge based on your skill level. RedBearLab tries to make this more accessible to makers familiar with the Arduino IDE with their open source Arduino library for Nordic nRF51822 IC (github.com/RedBearLab/nRF51822-Arduino), an ARM-M0 SoC with BLE capability. More advanced users can still use KEIL, GCC, or mbed.org.

With a maker board, some development skills, and good community support, you could be on your way to the next big IoT thing.

"We believe that DIYers and makers are the driving force for the adoption as well as innovation in the IoT space," Ma says. "The majority of IoT successes so far are from new startups with strong maker, open source, and crowd-sourcing backgrounds."

Monique DeVoe (Managing Editor)
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