Two years ago, a small group of engineers from a company called RF Digital launched a Kickstarter campaign for the RFduino, a Bluetooth Low Energy (BLE) 4.0-enabled embedded controller that would be compatible with the open-source Arduino platform. The RFduino got significant traction with both hobbyists and major corporations as a development platform for everything from one-of-a-kind "maker" projects to prototypes for Internet of Things applications. But while RDduino eased the hardware development path for wirelessly connected devices, RFduino developers still faced another problem faced by all hardware developers: building applications for iOS or Android and getting them through the app approval process.

That chokepoint in device development was part of the inspiration for RF Digital's next big (or small, actually) thing. A new custom chip designed by RF Digital called Simblee makes it possible for device developers to embed mobile application behaviors in their devices themselves, passing interface information over BLE to a generic framework Simblee app on the mobile device. The result is that developers don't have to write a single line of Swift, Xcode, or Android code to produce working applications for their inventions, and they don't have to wait for Apple's or Google's app store to approve each individual app.

But Simblee does more than just ease the development path. The device's extremely low connection latency and its timing accuracy give it potential applications in everything from wearable medical devices to gaming to industrial applications. It also provides an easy onramp for developers to build Internet of Things applications. And it's so small and inexpensive that it can be embedded in a wide variety of objects, like toys, store shelves, restaurant tables, and aircraft engines.

"Simblee means Simple BLE," said Armen Kazanchian, the founder of RF Digital. "And the two E's at the end are for Everyone and Everything—as in it can be used by everyone for everything." Kazanchian gave Ars a demonstration of Simblee in a number of sample applications via video conference in advance of its launch, and we'll go hands with the technology when Simblee begins shipping.

There are a number of commonalities between Simblee and the RFduino. Like RFduino, Simblee is programmed using Arduino Sketch code. Simblee can be programmed through the Arduino Sketch IDE or with the Sublime editor, Kazanchian said. But Simblee extends the Sketch format used by RFduino by including interface logic for the mobile application it interacts with (currently only on iOS, though an Android version of the application is in development).





The Sketch code can also define Internet back-ends for the device-specific application, configuring the mobile app to send data to a specific Web address. Kazanchian told us that RF Digital will provide sample server-side code that includes a WordPres plugin for Simblee, allowing devices to create blog posts based on interaction with a mobile device as well as Twitter and Facebook plugins. Users will be able to leverage the code for their own applications or use it as a reference to build more sophisticated cloud computing back-ends that interact with the devices.

Simblee's sensitivity to Bluetooth signals can be tuned to different tolerances. The Simblee chip can be programmatically set to allow interaction from hundreds of feet away (as would be necessary in a toy remote control application) or only from inches away. Kazanchian demonstrated "writing" on a board of Simblee chips linked to LEDs with another Simblee-equipped device, changing the color of the LEDs as the device passed over them.

The tunable sensitivity of Simblee, Kazanchian said, could be used to limit access to particular interfaces to someone in very close proximity. "Say you have a Wi-Fi router with a Simblee chip in it," he said. "Normally, you have to plug into it through an Ethernet port on the LAN side to provision it."

With a Simblee-equipped router, he said, you could bring a mobile device up alongside it, "bring up the Simblee app next to it, and the configuration application gets transferred to the phone." In an instant, the configuration screen for the router would be on the phone or tablet, and it could be up and running without ever having to jack into the router.

The Simblee chip is custom-designed by RF Digital. The chip will be produced by Flextronics. Kazanchian added that "everything from manufacturing to packaging will be done in the US."

The new hardware also brings a number of improvements over RFduino's Bluetooth capabilities. For one, Simblee's signal processing latency is about three milliseconds, which Kazanchian said makes it potentially interesting to the gaming industry for things like motion tracking. And the timing between Simblee chips connected in a network can be synchronized with 10 microsecond accuracy—so, for example, wearable medical sensors could provide accuracy previously only possible with more expensive, stationary hospital equipment.

Another innovation within Simblee is a new "interference resistance" algorithm in the chip's wireless communications that allows it to continue to communicate in more challenging radio frequency environments, Kazanchian said. This could allow Simblee to be applied to more mission-critical tasks such as automotive and avionics applications.

For many larger organizations, the Simblee mobile app framework may just be a way to quickly prototype their own applications. But it could also provide an easy way for smaller organizations to deploy applications without getting into the "app" business, embedding logic for applications in their own retail environments or products. Instead of having to download a private-labelled app, customers would be able to use a more common app in a wider variety of scenarios. Since the actual application logic would reside in a thing instead of an app and the mobile device would only provide an interface and a connection to the Web, it would be more like visiting a website that interacts with real-world objects. And that may be the most interesting thing about Simblee in the long run as it broadens the definition of "things" in the Internet of Things.

Listing image by RF Digital