mjb/altos/src, branch plot-gps-height

altos: Add Kalman filter to MicroPeak

2013-01-16T23:21:24+00:00

This filters altitudes more accurately and also allows tracking of acceleration, which is used to discard height data generated by ejection charge noise Signed-off-by: Keith Packard

altos: Add computation of MicroPeak Kalman correction coefficients

2013-01-16T23:21:24+00:00

Signed-off-by: Keith Packard

altos: Correct model error covariance matrix

2013-01-16T23:21:24+00:00

Finally found a couple of decent references on how to set the model (process) error covariance matrix. The current process matrix turns out to be correct for a continuous kalman filter (which isn't realizable, of course). For a discrete filter, the error in modeled acceleration (we model it as a constant) needs to be propogated to the speed and position portions of the matrix. The correct matrix is seen in this paper: On Reduced-Order Kalman Filters For GPS Position Filtering J. Shima 6/2/2001 This references an older paper which is supposed to describe the derivation of the matrix: Singer, R.A., “Estimating Optimal Tracking Filter Performance for Manned Maneuvering Targets,” IEEE Transactions of Aerospace and Electronic Systems, AES-5, July 1970, pp. 473-483. This change has a minor effect on the computed correction coefficients; it should respond more reasonably to acceleration changes now. Signed-off-by: Keith Packard

Merge branch 'master' of ssh://git.gag.com/scm/git/fw/altos

2013-01-12T17:57:22+00:00

micropeak: Record samples before boost detect

2013-01-12T17:45:31+00:00

This saves a ring of 16 samples while waiting for boost, and then goes back through those looking for the first sample higher than the ground and writes the remaining ones to the log so that we get a more complete log of the flight Signed-off-by: Keith Packard

Merge remote-tracking branch 'origin/micropeak-logging'

2013-01-11T05:48:12+00:00

altos: Time out reading packet data from cc1120 after 100ms

2013-01-11T05:44:18+00:00

Sometimes the radio will give a spurious wakeup indicating that a preamble seems to have arrived, but no packet data will appear. In this case, abandon the packet reception and go back to waiting for a preamble again. This releases the SPI bus for other users and also avoids missing packets. Signed-off-by: Keith Packard

Merge branch 'master' of ssh://git.gag.com/scm/git/fw/altos

2013-01-09T05:12:17+00:00

Allow CC1120 to sit on other SPI busses

2012-12-31T22:22:37+00:00

Reading the incoming data bypasses the SPI API and touches the SPI data register directly; which port that is needs to be specified in the pins file Signed-off-by: Keith Packard

altos: megadongle radio int is C13, not C14

2012-12-29T06:05:31+00:00

Hard to get interrupts when listening to the wrong pin Signed-off-by: Keith Packard