Bluetooth standards for cycling sensors

The Bluetooth Special Interest Group (Bluetooth SIG) announces acceptance of new Cycling Speed & Cadence profile. This standard better enables manufacturers to design fitness devices that they know will communicate with other Bluetooth compliant devices.

Various types of Bluetooth devices communicate with each other through standardized profiles which define the role of the device. Mobile phone headsets, for example, use the aptly named “Headset Profile,” which encodes audio and includes commands to answer the phone, hang up, and adjust volume. Heart rate monitors use the “Heart Rate” profile. Different profiles for medical devices measure things like blood glucose, blood pressure and body temperature.

The new Bluetooth 4.0 Low Energy Cycling Speed & Cadence profile enables interoperation between input devices and Bluetooth devices. Sensors transmit cycling speed, distance, and pedal cadence to a Bluetooth device such as a smartphone, sport watch, or cycle computer.

Today, wireless cycling sensors typically use Garmin’s ANT+ protocol to transmit cadence and power data to the handlebar mounted cycle computer or “head unit.” Choices of head units are limited to a couple of Garmin models and a handful of other solutions. Interoperability is a crapshoot. The Bluetooth Cycling S&C profile is a direct shot across the bow of Garmin’s ownership of low powered fitness sensor electronics.

ABI Research, Inc. forecasts shipments of Bluetooth enabled sports and fitness devices will grow ten-fold from 2011 to 2016, totaling 278 million and representing over 60 percent of the total available market. According to ABI’s Jonathan Collins, principal analyst in telematics and M2M technologies, this is being driven by the trend to move away from proprietary solutions [read "ANT"] and toward Bluetooth Smart devices.

The Bluetooth SIG also announced finalization of a Running Speed & Cadence profile, which supports sensor data for running cadence, stride length, and total distance. Coming Real Soon Now are additional profiles for Cycling Power, Location & Navigation (e.g. GPS data), and Environmental Sensing (altitude, air temp, wind speed & direction, which I anticipate Strava utilizing where available to maybe footnote those wind-assist KOMs).

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