Computed fields from fit file messages

[david]

You can now create custom activity and interval fields that process fit file messages with scripts. Tick the “Processes fit file messages” box:

Your script will be run when the file is first processed or re-processed. Here is an example script that extracts heart rate monitor details from the device_info messages:

{
  let hrm
  for (let di of icu.fit.device_info) {
    if (di.device_type?.value !== 120 /* HEART_RATE */) continue
    console.log("di " + di)
    let manufacturer = di.manufacturer?.valueName
    if (!manufacturer) continue
    let product = di.product?.value
    if (product) {
      if (manufacturer === "GARMIN") product = icu.fitSdk.enumValueName('GARMIN_PRODUCT', product)
      else if (manufacturer === "FAVERO") product = icu.fitSdk.enumValueName('FAVERO_PRODUCT', product)
    }
    let serial = di.serial_number?.value
    hrm = manufacturer + (product ? " " + product : "") + (serial ? " " + serial : "")
  }
  hrm
}

You need to poke around on fitfileviewer.com and in the FIT SDK to figure out what to look for.

There is documentation for the fit and fitSdk objects here.

I am going to be adding heart rate monitor related fields soon but its still a nice example of what can be done with this feature.

[Daniel_Harris]

This is amazing! Thank you David

[CuriousEndurance]

What an update, all the possibilities!

[david]

Here is another example. This one prints out the first 1000 messages from the file with fields:

{
  let c = 0
  for (let m of icu.fit) {
    console.log("[" + c + "] " + m._name + " " + m._num + ": " + m.join(", "))
    if (++c >= 1000) break
  }
}

[0] file_id 0: serial_number=3332779479, time_created=1060332298, manufacturer=1, product=3558, type=4
[1] file_creator 49: software_version=300
[2] unknown 288: unknown=1060332300
[3] event 21: timestamp(s)=1060332300, data=0, event=0, event_type=0, event_group=0
[4] device_info 23: timestamp(s)=1060332300, serial_number=3332779479, manufacturer=1, product=3558, software_version=3.0, device_index=0, source_type=5
[5] device_info 23: timestamp(s)=1060332300, manufacturer=1, product=3558, software_version=3.0, device_index=1, device_type=4, source_type=5
[6] device_info 23: timestamp(s)=1060332300, manufacturer=1, product=2957, software_version=2.5, device_index=2, device_type=0, source_type=5
[7] device_info 23: timestamp(s)=1060332300, serial_number=3437995431, cum_operating_time(s)=507058, unknown=2, unknown=2977473959, manufacturer=1, product=3299, software_version=2.5, battery_voltage(V)=2.99609375, device_index=3, device_type=120, hardware_version=49, battery_status=3, ant_network=1, source_type=1
[8] device_info 23: timestamp(s)=1060332300, serial_number=1482690984, cum_operating_time(s)=123456, unknown=2, unknown=84629600, manufacturer=263, product=12, software_version=4.8, battery_voltage(V)=4.19921875, device_index=4, device_type=11, hardware_version=4, battery_status=2, ant_network=1, source_type=1
[9] device_info 23: timestamp(s)=1060332300, manufacturer=36853, product=10, software_version=126.1, device_index=5, device_type=8, source_type=5
[10] device_info 23: timestamp(s)=1060332300, manufacturer=1, product=3559, software_version=0.06, device_index=6, device_type=12, source_type=5
[11] unknown 22: unknown=1060332300, unknown=2, unknown=2, unknown=4, unknown=1, unknown=3, unknown=5, unknown=4
[12] unknown 141: unknown=1060332300, unknown=1060127982, unknown=1060451982, unknown=1
...

[rolandplanitz]

Awesome. Any chance we could use that to match that activity to a gear component to track it without mapping it to the gear.

[Nitish_Nag]

It would be great if there was a library people can contribute scripts they create so others can use it too, similar to the charts library etc.

[david]

You can share custom activity fields with everyone. There are already a lot of them.

[david]

Unfortunately not. Having components or multiple gear items per activity requires quite a lot of changes.

I did just add custom fields to the ones you can use for gear filters.

[Nik_Om_Cinderella_Ri]

They’re bound to still be gears what are not connected to the head unit and be written to the fit file.

[stefcameron]

This is awesome, thank you, David! I was able to figure out how to pull battery voltages and statuses for my power meter and HRMs which is so convenient!