Excited by the Fitbit Charge 2’s second by second heart rate data, but frustrated by the lack of an easy export function for accessing this data in raw form, I rolled a very quick Node.js app to give me CSV-formatted raw data from Fitbit. Note that to access the APIs I am using, you either need special approval, or a Personal application registered on the Fitbit developer portal.
It looks like this, after the app is initially authorized:
Clicking the “Get HR for Today” link gives me this raw CSV:
And so on.
Here’s the bare bones code, posted as a gist on GitHub: