Sunday 26 May 2013

Android App Updated (version 0.6b)

I have just completed a major update of the Android app. It should be in the play store in the next 24 hours. This has been prompted by the next version of the prototype hardware, which has been shipped to a few people and will be ready for general release in the coming weeks. The key updates to the Android app are:

Kalman Filtered Pressure Stream. The hardware device sends raw pressure measurements 50 times a second. I was previously getting altitude and vario information from a complex set of IIR filtering and linear regression. That has now all changed. A kalman filter is used to keep a running estimate of position (altitude) and velocity (vario). There is only one parameter to set, the position noise (there are some other paramters that are hard coded, but these will not affect users). This turns the steam of pressure data into a stream of Alt and Vario 1 data based on the position noise parameter. The Alt and Vario 2 data is further damped using IIR filters. This makes a much simpler mix of settings and is much more computationally efficient.

Audio. The audio in the Android app was updated to make it more computationally efficient and responsive. I got rid of the "sink, sink" sound and replace it with a more familiar tone. I have also changed the default lift base frequency to 1000Hz. This is much louder on most phones speakers. The new bunch of settings should be fairly self explanatory if you read the description in the menu. Just make sure the cutoff for lift is less than or equal to the threshold, and the cutoff for sink is greater than or equal to the threshold.

Hardware Settings. In the settings menu is a sub menu that allows you to set the settings on a connected hardware device. From hardware prototype version 6 you should get a dialog similar to the one shown below. Earlier hardware versions can not access this menu. The audio settings are similar to the settings in the Android app, but are completely independent. Audio on the hardware can be enabled either when the hardware is connected to an Android device, or not, or both, or neither. The secondsBluetoohWait parameter controls how long the hardware will be available for a bluetooth connection when first turned on. The rateMultipler parameter controls how fast the lift beeps beep. 0.5 is twice as fast as 1.0. The volume parameter is a rudimentary way to set the hardware audio volume. 1.000 is default, 0.100 is about half, 0.010 is pretty quiet.

I suspect that some users of the new BlueFlyVario will only ever use the Android App to affect the hardware settings on the device.

Flight Altitude. This is a new field that shows the difference between the alt at the start of the flight, and the current alt.

In addition there are many more bug fixes, and I suspect a few new bugs. Contact me if something does not seem to work as you expect.