| Age | Commit message (Collapse) | Author |
|---|
|
The altimeter was erroneously made to add to the sea level air pressure instead of subtracting from it, which resulted in inverted behaviour. This has now been fixed.
This also allows setting a negative altimeter offset
|
|
Asteroid watches don't generally have a pressure sensor, as it isn't generally exposed by android's HAL. Hence we use the basic 12Pa/m relationship to calculate an approximation for altitude from the pressure sensor (barometer) reading. This kind of precision seems appropriate given that a) we don't expect this to be used as a flight computer and b) the android barometer, while precise, isn't super accurate anyway.
In order to make the reading a bit more useful, we allow the user to calibrate the current altitude. Since we allow separate calibration of this from the barometer calibration, we use the uncalibrated barometer reading as the input for our calculation.
|
|
This is meant as a multitool app that currently allows usage of compass and barometer.
The app includes a means of 'calibrating' the barometer reading. This is not a system level calibration and only affects the app (or any other apps that choose to use the value I'm setting in dconf). The mechanism was initially inspired by the same feature on Casio's watches: under WearOS, all of Casio's apps use a shared calibration offset for barometer.
The calibration aims to rectify the infamous inaccuracy of the android barometer sensor. While the sensors are generally very precise and can sense small changes in air pressure, the sensors often lose calibraton and hence suffer from zero error. This can be somewhat helped by allowing the user to set a zero point - it seems this allowed Casio to make the sensor into an actually useful feature.
There was discussion about making this calibration into a system-level feature (for example, as a patch to sensorfw or to QtSensors) but I think it's reasonable to expect the sensor to always return the raw value (even if it is wrong) and then have the calibration as a separate, opt-in feature.
|
