package fit
Install
Dune Dependency
Authors
Maintainers
Sources
sha256=692faf7156994c7ff9ea84c668f6d37d7e5a5ac0a4f7dacfb4c19ed66193208f
sha512=a989fac0c41b5f627f3d1547e3deb941107dcd34d9310d35cc40da797ce4bfc9dd982ba69d5e192c989791f2783194b325be701d52f9b743a05078add24c9e84
README.md.html
README.md
FIT
This is a minimal OCaml project to parse FIT files as they are produced by personal fitness devices. FIT is a binary format invented by Garmin that groups basic values in records, which typically include a timestamp.
{
"msg": "20",
"13": 11,
"2": 1900,
"5": 1732414,
"6": 0,
"1": 1669620,
"0": 622905943,
"253": 971857351
}
Each record has a global message number (like 20) which defines the purpose of the record and a number of values in position slots. The meaning of these is defined in the FIT Protocol but this library (so far) only implements the parsing. For example, message 20 is called record in the FIT protocol and slots have these meanings:
0 position_lat
1 position_long
2 altitude
5 distance
6 speed
13 temperature
253 timestamp
Values are further scaled and shifted, which is also defined in the protocol, and this transformation is only implemented for a few fields of the "record" message:
{
"msg": "record",
"timestamp": "2020-10-17T06:25:19",
"0": 622927716,
"1": 1703145,
"speed": 2.745,
"distance": 277.23,
"altitude": -118.8,
"temperature": inf
}
CLI
This code is primarily intended as a library but it also provides a small binary. The fit
command emits the data to stdout in JSON format. I am using this currently for inspecting FIT files. The FIT file in data/
is from a bike computer.
$ fit data/xpress-4x-2020-10-17.fit | head -25
[
{
"msg": "0",
"3": 5122,
"4": 971850094,
"1": 267,
"2": 1803,
"5": 0,
"0": 4
},
{
"msg": "68",
"0": 17,
"1": 1,
"2": 0,
"3": 10,
"4": 255,
"5": 0,
"6": 0,
"7": 0,
"8": 232,
"9": 0,
"10": 60,
"11": 19693
},
...
Installing FIT
Version 1.0.1 has been published as an Opam package such that it can be installed from Opam:
opam install fit
You can also pin it directly for access to unpublished changes:
opam pin add -y git+https://github.com/lindig/fit
Once installed, you can use it:
$ utop -require fit -require rresult
utop # open Rresult;;
utop # Fit.read "data/xpress-4x-2020-10-17.fit" >>= fun fit ->
Fit.to_json |> R.return;;
The fit
binary takes a FIT file as argument:
$ fit data/xpress-4x-2020-10-17.fit | tail -15
"58": 11,
"20": null,
"21": null
},
{
"msg": "activity",
"timestamp": "2020-10-17T08:22:35",
"0": 7263000,
"5": 971860957,
"1": 1,
"2": 0,
"3": 26,
"4": 1
}
$ fit --help
Resources
https://developer.garmin.com/fit/protocol/
https://www.pinns.co.uk/osm/fit-for-dummies.html
Contribute
If you find this useful, please contribute back by raising pull requests for improvements you made.