Wrong Value in turn field (AIS1-3) ?

[yves84]

Hi,

Here an output from an ais msg:

{'type': 1, 'repeat': 0, 'mmsi': 'XXXXXX', 'status': <NavigationStatus.Undefined: 15>, 'turn': -128, 'speed': 0.1, 'accuracy': 1, 'lon': 4.303693333333333, 'lat': 51.270986666666666, 'course': 360.0, 'heading': 511, 'second': 55, 'maneuver': <ManeuverIndicator.NotAvailable: 0>, 'raim': 1, 'radio': 82243}

The "turn"-Field with -128 is not correct i think. A value of 128 (positiv) is the value for "no information" and it is not possible to save -128 with 8 bits (singed int -127 - 128).

Ty & Gz!

[yves84]

I'm sorry. Was my mistake. The range is -128:127.

In https://gpsd.gitlab.io/gpsd/AIVDM.html#_types_1_2_and_3_position_report_class_a

128 (80 hex) indicates no turn information available (default)

there compare the "raw" value 0x80 -> -128 (But write only 128). I was confusing...