Pressure difference last 3 hours

Hi,

I found on the internet a small program and I want to modify it to display the value of the barometer difference between current pressure and the last 3 hours.

Does anyone have an idea what I need to change.?

Thanks a lot

if ((Toybox has :SensorHistory) && (Toybox.SensorHistory has :getPressureHistory)) {

var last1=null, last2=null;

var itr = Toybox.SensorHistory.getPressureHistory({});

var sample = itr.next();

while (sample != null) {

if (sample.data != null) {

last1 = sample.data;

break;

}

sample = itr.next();

}

sample = itr.next();

while (sample != null) {

if (sample.data != null) {

last2 = sample.data;

break;

}

sample = itr.next();

}

if (last1 != null && last2 != null) {

return last1<last2 ? "decrease" : last1>last2 ? "increase" : "same";

}

return null;

0 jim_m_58 over 1 year ago

So what does your code actually do when you run it? Are you using the sim or a real device? In the sim, what you see in SensorHistory is canned data - here's a graph from the sim. Notice it starts low, gets the highest in the middle, and then drops back to the same low.

0 FlowState over 1 year ago

It looks like the code you posted:

- grabs the 2 most recent valid pressure samples

- compares them and returns the result of the comparison: "decrease", "increase" or "same"

3026192 said:
I want to modify it to display the value of the barometer difference between current pressure and the last 3 hours.

I'll assume that:

- the most recent valid pressure sample in the history is the "current pressure"

- we want to compare the "current pressure" with any valid sample that's at least 3 hours older

- you want to change the existing code as little as possible

Try this:

if ((Toybox has: SensorHistory) && (Toybox.SensorHistory has: getPressureHistory)) {
  var currentSample = null, previousSample = null;
  var itr = Toybox.SensorHistory.getPressureHistory({});
  var sample = itr.next();
  while (sample != null) {
    if (sample.data != null) {
      currentSample = sample.data;
      break;
    }
    sample = itr.next();
  }
  sample = itr.next();
  while (sample != null) {
    if (
      sample.data != null &&
      currentSample.when.value() - sample.when.value() >= 3 * 60 * 60 // 3 hours, in seconds
    ) {
      previousSample = sample.data;
      break;
    }
    sample = itr.next();
  }
  if (currentSample != null && previousSample != null) {
    return currentSample < previousSample ? "decrease" : currentSample > previousSample ? "increase" : "same";
  }
}
return null;

I made the following changes:

- renamed last1 to currentSample and last2 to previousSample

- for the code which sets the second sample (last2/previousSample), added the following condition:

currentSample.when.value() - sample.when.value() >= 3 * 60 * 60 // 3 hours, in seconds