symbol not found error; only on Edge 820 how to fix?

As noted in DC Rainmaker's review, Edge 820 Explore does not support power meters. (As opposed to Edge 820, which does support power meters)

As for the Edge Explore 820, here’s how it’s different than the base Edge 820:

– No WiFi
– No Ambient Light Sensor
– No ANT+ Power Meter or Shifting Support
– No Structured Training Support (i.e. structured workouts)
– No advanced metrics like performance indictor, FTP, etc…

Devices which don't support power meters typically do not have power-related ActivityInfo fields such as currentPower, averagePower, etc. (Meaning that the symbol itself isn't present on the class.)

The docs for ActivityInfo.currentPower claim it's available for "Edge 820 / Explore": https://developer.garmin.com/connect-iq/api-docs/Toybox/Activity/Info.html#currentPower-var

It's also worth noting that there's a single edge820 device in CIQ, which is also referred to as "Edge 820 / Explore"

From context, it's pretty clear that the one edge820 device in CIQ actually refers to two products: "Edge 820' and "Edge 820 Explore". I have no idea why this decision was made, because it means that if you want to create an application that targets power meter support, you have no way of including Edge 820 but not Edge 820 Explore. It also means you probably have no way of simulating Edge 820 Explore (so you could see that it lacks power meter support).

Anyway, here's the fix for your code:

if (info has :currentPower && info.currentPower != null) {
  potencia = info.currentPower;
} else {
  potencia = 0;
}

You'll have to do that for all power-related fields, and possibly other fields related to advanced training or cycling. (Any field which has a list of supported devices in the docs could potentially be missing.) Since there's no shifting support in Edge 820 Explore, I assume frontDerailleurIndex and backDerailleurIndex will likely be missing, too.

(Personally I wouldn't use 0 for missing/null data tho. For my apps which display activity data, I store null internally for null/missing data, and display something like "--" to the end user.)

I also think Garmin should improve their documentation to note that just because a symbol is *sometimes* available for "Edge 820 / Explore', doesn't mean it's *always* available, since that's really 2 different products with 2 different feature sets.

I filed a bug report for the docs:

forums.garmin.com/.../ciq-documentation-doesn-t-make-it-clear-that-edge-820-explore-is-2-devices-with-different-featuresets-e-g-edge-820-explore-lacks-power-meter-support