Garmin Edge 520 barometer manufacturer

I don't believe that information has been posted anywhere, and from teardowns I have seen of other devices it might be difficult to identify the exact barometer model used. You could always take it apart and check the model and manufacturer for yourself, but that information may not mean much as the raw pressure data is not currently exposed through CIQ. The sensor reading goes through some processing to calibrate it to reference, and that processing can cause the three parameters you listed above to change. Until an interface to the raw sensor data is available, it might be best for you to make your own measurements under controlled test conditions so you know how the provided value behaves.

Whoops, somehow didn't notice that, thanks for pointing it out. Ignore what I said previously then.

The question is what Garmin means with "raw data". The typical used barometric sensors (e.g. STMicro LPS22HB) have an internal temperature sensor to compensate the temperature effect on the barometric pressure. As I expect "raw data" is not really "raw", it is already temperature compensated. If you want to program a data field for Grade based on the pressure difference over a certain distance you have to consider the temperature effect in the barometric formula.

The value provided by this API is temperature compensated.

Hey,

I've created a ticket to better describe this in our documentation.

Thanks,
-Coleman

Thank you for the clarification. Now it is easy to get a grade data field:

• p1: pressure a the start point in Pa
  
• p2: pressure at the end point in Pa
  
• dh: height difference in meters between end point and start point
  
• dl: distance in meters between end point and start point
  

dh = 8434.15 * (p1 - p2) / p1
grade = dh / dl

Here you have the grade (multiply it with 100 to get the value in percent)