[F]rank is quite taken back by the VTI SCP1000 altitude sensor accuracy in the TI Chronos. The watch displays the letters “ALT” as the bottom and the numbers at the top. This however, results in displaying a maximum altitude of 9999 when the altimeter is set to feet. So he programmed the watch to display the “ALT” at the top and the feet at the bottom, providing a total of 5 digits for number display.
He’s also added a couple of features to the altitude section of the code:
“ACCA” is the accumulated altitude (so far). “PEAK” is the peak altitude reached (so far). “DIFF” is the difference between your starting altitude (when you turned the altitude accumulator on) and your current altitude. In this example I went for a little bike ride and the display is set in metres. You can see I did 424 metres of vertical climbing, reached a peak altitude of 338 metres, and now I’m back at my starting point, the watch saying I’m only 1 metre above the altitude I started off from. Use the up/down buttons to switch between these 3 altitude-accumulator displays.
The modified Chronos code is available at his blog page.
Hey,
I also made some more advanced calibration code by manipulating the driver/vti_ps.c, see here: http://bluesceada.blogs.ghostdub.de/2010/12/06/msp430-chronos-more-advanced-altitude-calibration/
Thanks for sharing. Looking at it now.