Fit Contributor

Hi,

just a question to the FitContributor: If I calculate the average values of an high-intensity period of an interval and write those values to the Fit file, does Garmin connect web make those values somehow visible or is it just a value in the Fit file?

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jim_m_58 over 8 years ago +1

There's a post here someplace about strings and the default length being 1. I('ll see if I can find it. Here it is: https://forums.garmin.com/showthread.php?359132-FitContributor-DATA_TYPE_STRING…
IMGrant over 8 years ago +1

By the way: I put this code in the onTimerLap() method, nevertheless, it seems that the fit file is written __before__ this code is executed which means that the data is written to the next lap :-( Is…
topcaser over 8 years ago +1

Hi IMGrant,

I already thought about this, but there is one reason I don't want to do this: performance. It's a really complex calculation I have to do. IMO it makes no sense from a datafield perspective…

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topcaser over 8 years ago

No one?

travis.vitek over 8 years ago

This is covered in the programmer's guide... here.

topcaser over 8 years ago

Thanks for that information. I have coded this now:

In the resources file:

<fitContributions>
		<fitField id="0" displayInChart="true" sortOrder = "0" precision="0" chartTitle="@Strings.AvHrGraphLabel" dataLabel="@Strings.AvHrGraphLabel" unitLabel="@Strings.AvHrUnits" fillColor="#FF0000"/>
	</fitContributions>

In the View file:

function setupField(session) {
		avHrField.session.createField("average_heartrate", 0, FitContributor.DATA_TYPE_UINT8, { :mesgType=>Fit.MESG_TYPE_RECORD, :units=>"bpm" });
	}

and in the compute(info) method:

hiAvHrField  = sumOfLapHr  / numOfLapSamples;
  avHrField.setData(hiAvHrField.toNumber());

Nevertheless, if I execute the code in the simulator I get this message for the setData line:

Failed invoking <symbol>
Unexpected Type Error

What am I doing wrong? Note that the hiAvHrField will never reach 255, therefore IMO the DATA_TYPE_UINT8 should be fine.

travis.vitek over 8 years ago

The object you call setData() on should be an object returned from createField().

topcaser over 8 years ago

OK, thanks for that information. I had a type error in my code. The correct code is:

function setupField(session) {

		avHrField = session.createField("average_heartrate", 0, FitContributor.DATA_TYPE_UINT8, { :mesgType=>Fit.MESG_TYPE_RECORD, :units=>"bpm" });

	}

Nevertheless, when is the setupField method called from the OS? I belief that the function is not called at all.

travis.vitek over 8 years ago

No, the setupField() function that you snipped from the programmer's guide is just an example. Nothing calls it. If you need an example, the MoxyDataField sample program included with SDK should have everything that you need.

Travis

topcaser over 8 years ago

OK, got it running, at least got it compiler clean. I created a .prg file and tried out the datafield but the graph is not shown in GC web. The fitContributor needs to get a certain permission. Can it be that the permission is not given if one sideloads the datafield?

travis.vitek over 8 years ago

The data won't appear in Garmin Connect until you upload your app to the app store. If you're not ready to upload to the store, you should be able to use the monkeygraph utility to display the data from fit files captured in the simulator and from the device.

topcaser over 8 years ago

Travis, you are really the best. I have tried monkeygraph out and the data is shown there. Many thanks to you for getting this running. My datafield will goes live in some days not least due to your help.

topcaser over 8 years ago

Hi,

just another question. I tried to write a string at the end of my workout to the .FIT file. The compiler did not complaint but in the end of the simulation I get following failure:

setData string too long for allocated space

The API says nothing about string length limitations. My string had 32 characters....