MembersPage/GergelyLezsak/WheelSpeed (2009-05-21 18:33:04)

WheelSpeed experiments

Made some tests with 1.1.50 and 1.1.53 Non-PS2 firmware.

Hardware on PS2/CLK pin:

Signal with connected as above:

whscope1.gif

Signal with a 1uF capacitor to GND

whscope2.gif

(it seems too large for higher frequencies)

I've made tests with no, 100nF, 200nF, 500nF and 1uF capacitors and adjustments of edge and minimal period time. It didn't really change interpreted signal quality.

At lower speeds the signal is all right, but at higher speeds it becomes very noisy

highspeedlog.gif

more logs here: http://quasar.dynaweb.hu/~lezsi/vems/wheelspeed.zip

I don't have a 6 speed gearbox, but have a long diff. ratio so calibration data of gear 5 (233) and 6 (255) is close enough for the routine to make bad guesses. (This range is tight anyway, strong cars go faster than 254km/h at 5000rpm)