Message Type 138, $PACCEL2
Proprietary NMEA message containing hard acceleration/deceleration information obtained from GPS velocity or accelerometer data. This NMEA message is designed to be sent whenever the GPS hard acceleration/deceleration thresholds are exceeded (see cmd accelsensor? cmd gpsaccel?).
PACCEL2 contains data obtained from the alternate sensor, that is, the sensor not configured in cmd accelsensor?. PACCEL2 is typically used for testing purposes only.
Message format is:
$PACCEL2,hhmmss.ss, llll.llll,a,yyyyy.yyyy,b,vvv.v,uuu.u,ddmmyy,ggggggggggg*hh<CR><LF>
Where:
hhmmss.ss is the UTC time in hours, minutes, seconds, and decimal seconds
llll.llll is the position latitude in degrees, minutes and decimal minutes
a is N(orth) or S(outh)
yyyyy.yyyy is the position longitude in degrees, minutes and decimal minutes
b is E(ast) or W(est)
vvv.v is the velocity in km/h
uuu.u is the acceleration/deceleration in km/h/s
ddmmyy is the day, month and year
ggggggggggg is the modems ID
hh is the message checksum
Example:
$PACCEL2,161059.00,4915.4209,N,12259.8663,W,018.8,-04.0,260411,09604204933*27[0x0D][0x0A]
In the above example the recorded acceleration/deceleration value is -4.0 km/hr/sec, or -1.11 m/s2.
A reasonable value to set for a "hard" acceleration event should be around 10 km/hr/sec or 2.77 m/s2 (10/3.6=2.77)
1g = 9.8 m/s2 would be 35.3 km/hr/sec. For comparison, an extremely fast sports car is capable of 0-100 Kph acceleration of 7.6 m/s2 or 27.4 km/hr/sec.