How to track time since phone disconnected?

Former Member over 4 years ago

I am displaying temperature on a watch face, and after a while the temperature is inaccurate simply because my watch has not connected with my phone. I want to change the temperature reading to "--" after the watch has been disconnected for more than 8 hrs. I am thinking I can do this by capturing the moment in time it disconnected and then using an if statement or a timer for an 8 hr period. But I do not know how to capture the instance that the phone disconnects. Do I need to implement this in the background as a temporal event? If so, how do I use the phone disconnect as a trigger?

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jim_m_58 over 4 years ago +1

Depending on your weather source, the data you receive might have a time stamp. For example, OWM has it as

"dt":1545583620

and for Garmin Weather, it's in currentConditions, and it's observationTime…

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jim_m_58 over 4 years ago

Depending on your weather source, the data you receive might have a time stamp. For example, OWM has it as

"dt":1545583620

and for Garmin Weather, it's in currentConditions, and it's observationTime.

Both are in "unix time" (number of seconds since Jan 1,1970, 00:00 UTC)

So, Time.now().value() is the current time in "unix time:, and that minus the timestamp, is how old (in seconds) the data is.

Convert that to hours, and if it's greater than x hours, the data is stale, so display "--" for temperature.

Much easier than monitoring the phone connection

Former Member over 4 years ago in reply to jim_m_58

Ah, thanks! I did not know about the observationTime feature. That is much easier!

jim_m_58 over 4 years ago in reply to Former Member

It's also something to consider displaying along with the temperature - you can see how old the reading is - a few minutes vs a few hours.