Are the sensors on Fitbit Sense and Charge 5 & 6 the same?

[RadoslavaS]

Hi, I am planning to conduct a research study and want to ask if sensors used in Fitbit Sense (generation 1) and Fitbit Charge 5 / 6 are the same? I do not care about the features of watch, but rather about the hardware - the sensor for data collection. Thanks. 

[Gondwana]

What could be more important is whether you can access the sensor data in a way that you can use.

[RadoslavaS]

I access them through API and have a specific purpose for which this is
feasible. Do you know if the sensors are the same?

[Gondwana]

Which API?

[RadoslavaS]

fitbit api, from their program for developers. But in this question I need
to understand which sensors are used in the two devices and if they are
comparable in terms of hardware.

[Gondwana]

There are several Fitbit APIs. Please provide a link to the particular API you're proposing to use, then I can tell you which device's sensors it can access. Not all APIs are relevant to all device types. If you can't access a sensor's data, then it doesn't matter what type of hardware it is.

[Guy_]

Hi @RadoslavaS - like @Gondwana says, for instance, a Sense 1 has a gyroscope and only the original Versa has one too in the smart watches.

The heart rate sensor on the Sense 1 is different to prior Versas and I believe is different to the Charge 6. The Charge 5 may be the same as the Versa. You probably can find more about that based on initial release date. The Charge 6 is the latest generation hardware wise.

[RadoslavaS]

Where can I find the release dates or other information relevant for identifying sensor types, please? 

[RadoslavaS]

Hi Peter, thanks for the clarification. I am planning to extract all the data points within Web API, with focus on the following datapoints: steps, heart rate, activities (automatic recognition and whatever is available) , sleep related metrics, body metrics. I am collecting data from multiple participants and they are wearing different watches and I want to report on which watches sensors are different, as it might lead to some systematic shift in the data.

[Guy_]

@RadoslavaS- see the wiki. or a smartwatch overiew

Note of caution, comparing data across devices, and people, with their resultant disparate measurements is likely to produce inconsistent/incomparable information.

The variation of results [within the same watch model, due to differences in tolerances and operating issues] and the measurements from different people with incompatible wearing habits and behavioural activities may not give you anything near what you are hoping for..

In general they are better at spotting a long term trend for one watch and one person, but it could be a fun project.

[Gondwana · Accepted solution]

@RadoslavaSThanks for clarifying Web API. That's the only API that lets you extract data from all Fitbit types.

Teardown articles (eg, this and this) are probably your best bet for finding out hardware details, since Fitbit doesn't release the info.

It's quite possible that differences in the software algorithms used to convert raw sensor data into processed info (eg, heart rate) are more significant than the changes in sensor hardware. If so, I'd opt for the most recent watch.