Smart Sensors, Simplified

Date Posted: 25 November 2020

At Wildfire Sports, we frequently have customers enquire about the function, difference and compatibility of devices which use these protocols, so we decided to explain the technologies and address some common questions and problems.

Image by Polar

Whether you swim, run, ride, or do any sort of exercise or activity which you track using your smartphone, or any sort of Garmin, Wahoo Fitness, Polar device, the chances are you are familiar with (have been frustrated/confused by) Bluetooth, ANT/ANT+ sensor technology and the concept of ‘pairing’.

At first, pairing and setting up these sensors and devices can seem overwhelming and complex to the unfamiliar, and while manufactures like Wahoo Fitness and Garmin are making this process easier and more autonomous, it’s worth having a basic understanding of how these protocols work and differ from one another to make following the prompts easier.


ANT and ANT+

The most widely applied sensor technology used in exercise monitoring is the ANT, and now ANT+ protocol. ANT+ is a transmission protocol designed to wirelessly connect sensors to an array of devices. Owned by Garmin, ANT+ Wireless is a favourable protocol because of its low power consumption properties, and allows sensors to operate across several profiles, or classes of information (heart rate, speed, power, kilometres etc.), which allows for communication based on profile, not manufacturer. This also means one sensor can communicate with multiple devices, even simultaneously. For example, an ANT+ Cadence sensor can talk to a Wahoo KICKR, a Garmin Edge computer or a Forerunner, it doesn’t matter. We can compare this to Polar’s relatively outdated communication system, which does not allow their heart rate sensor to connect with any device that isn’t made by Polar.  



The present-day barrier for ANT+ however, is its lack of compatibility with today’s array of smartphones (with the exception of a limited number of mobile devices), meaning it is beginning to lose ground to its elder protocol brother, Bluetooth. Bluetooth has always been the protocol of choice for smartphone manufacturers when it comes to sensors and pairing, however ANT and ANT+ have previously found their place in the more niche market for competitive, ‘high performance’ sensors (bike sensors etc.).

An easy way to understand where ANT+ and Bluetooth sit in correlation with one another in the world of sensors and device pairing, is to think of ANT+ as the niche sensor protocol, and Bluetooth as the smart device technology of choice (most commonly utilised in smartphones, headphones, laptops,). The main reason for this has mainly been ANT+’s superior battery life and more reliable connection properties (drops out less often).

However, this is 2017, and smart technology is stampeding through the device marketplace, and their protocol of choice? Bluetooth. Why you ask? Bluetooth technology has been evolving in terms of its function, efficiency and reliability in leaps and bounds as more devices are becoming Bluetooth compatible, while ANT+ in recent years has remained relatively stagnant.

Smartphone compatibility is becoming one of the biggest selling points for exercise tracking technology in the fitness marketplace of today, simply because everyone has one, which removes the accessibility barrier of having to purchase separate, purpose built tracking devices which may be considered excessive by your recreational, non-competitive user.

So as manufacturers continue to bring out devices designed to provide users with the option to use ANT+ and Bluetooth interchangeably (which Wahoo Fitness is doing with their TICKR HR monitors and KICKR power trainers), unless ANT+ introduce something big in the next year or two, they risk being pushed out of the modern technology market completely by Bluetooth, as the technology continues to adapt and evolve.


Some final Troubleshooting tips for pairing and operating Bluetooth and ANT+ sensors/devices:

  • When pairing things like cycling computers and smart watches with your smartphone, check both device and sensor are in their ‘pairing ready’ state. This can be particularly fiddly, so make sure Bluetooth is enabled on both devices and try to put the devices in pairing mode at the same time (as close as possible).
  • Your devices just aren’t discovering each other? Sometimes it helps to either turn off Bluetooth/pairing mode and try again, or even turn off the device completely and start a-fresh.
  • Many ANT+ devices will enter a sleep mode after a period of inactivity, if your device is struggling to pick up a sensor, make sure you are moving it around to activate the accelerometer.
  • Keeping the sensor as close to the device as possible during set up also helps with the pairing process.
  • Battery power of devices can affect pairing efficiency and speed, so make sure they are charged up for best results.
  • ANT+ devices and sensors are run most commonly using CR2032 Lithium Batteries. 85% of the time, these can be the source of a sensor’s inaccuracy or inability to pair/hold a connection. It is always worth checking/changing the battery before taking further action or rendering your expensive piece of tech broken!
  • Remember that tampering with a device or sensor yourself will often void your warranty, so think twice before you undertake any DIY repairs. 

To browse further details and specifications of products with smart sensors, please click on the following links: 
Bike Trainers
Sports Watches & Activity Trackers
Handheld GPS Navigation