SCM Utils

SCM_Utils is a library of utilities for the Space Cows Project

ToDo

Thing left to do:

• Validate the computed positions.
• Deal with the over-precision of the computed positions.
• Migrate to the new message format.
• Handle processed messages
• Verify checksums on raw messages

Install

$ pip install git+https://github.com/jcu-eresearch/SCM_Utils.git

Usage

Decode a Raw Message Hex String

from scm.utils.scm_msg import scm_raw_message_decode

result = scm_raw_message_decode("013a4049000045fb1fdb210000000007840000041e2000032f2400002e2930")

Where result is:

OrderedDict(
    [
        ('id', 0),
        ('crc16', 5028),
        ('SF', 0),
        ('MC', 73),
        ('packet_type', < SCM_DF_Transmission_Payload.SCM_DF_Transmission_Payload_Tracking: 0 >),
        ('payload',
         OrderedDict(
             [
                 ('tracking',
                  OrderedDict(
                      [
                          ('flags', 0),
                          ('timeslot', 0),
                          ('longitude', Decimal('146.75968')),
                          ('latitude', Decimal('-19.331072')),
                          ('orientation', 0), ('activity', 0),
                          ('battery', Decimal('3.00')),
                          ('temp_min', Decimal('0.0')),
                          ('temp_max', Decimal('20.0')),
                          ('temp_alert', False),
                          ('points',
                           [
                               OrderedDict(
                                   [
                                       ('delta_km', 0),
                                       ('delta_m', Decimal('234.3750')),
                                       ('total_delta_m', Decimal('234.3750')),
                                       ('delta_angle', Decimal('22.50000000')),
                                       ('activity', 0),
                                       ('temp_alert', False),
                                       ('latitude', -19.32912466132596),
                                       ('longitude', 146.76053479568455)]
                               ),
                               OrderedDict(
                                   [
                                       ('delta_km', 0),
                                       ('delta_m', Decimal('250.0000')),
                                       ('total_delta_m', Decimal('250.0000')),
                                       ('delta_angle', Decimal('338.90625000')),
                                       ('activity', 0),
                                       ('temp_alert', False),
                                       ('latitude', -19.3289743495036),
                                       ('longitude', 146.75882251438833)]
                               ),
                               OrderedDict(
                                   [
                                       ('delta_km', 0),
                                       ('delta_m', Decimal('390.6250')),
                                       ('total_delta_m', Decimal('390.6250')),
                                       ('delta_angle', Decimal('340.66406250')),
                                       ('activity', 0),
                                       ('temp_alert', False),
                                       ('latitude', -19.32775718029063),
                                       ('longitude', 146.75844736292584)
                                   ]
                               )
                           ])
                      ]
                  ))
             ]
         )),
        ('bch32', 3025200),
        ('crc16_verified', True),
        ('bch32_verified', True),
        ('decode_type', 'raw')
    ]
)

Decode a Processed Message Hex String

from scm.utils.scm_msg import scm_processed_message_decode

message = {
    "ts": 1682983243409,
    "values":
        {
            "msg_date": "2023-05-01T23:20:43.409Z",
            "device_id": 184999,
            "msg_id": "1102739179156185088",
            "RAW_DATA": "000045FB1FDB210000000007840000041E2000032F2400",
            "SERVICE_FLAG": 0,
            "BCH_STATUS": 1,
            "MESSAGE_COUNTER": 60,
            "CRC_OK": True,
            "checked": "Y"
        }
}
BCH_STATUS = 0
if 'BCH_STATUS' in message['values']:
    BCH_STATUS = message['values']['BCH_STATUS']

result = scm_processed_message_decode(message['values']['RAW_DATA'],
                                      extra_id=0,
                                      service_flag=0,
                                      message_counter=message['values']['MESSAGE_COUNTER'],
                                      crc16_ok=message['values']['CRC_OK'],
                                      bch32_ok=BCH_STATUS >= 0)

Where result is:

OrderedDict([
    ('id', 0),
    ('crc16', 0),
    ('SF', 0),
    ('MC', 60),
    ('packet_type', < SCM_DF_Transmission_Payload.SCM_DF_Transmission_Payload_Tracking: 0 >),
    ('payload', OrderedDict([
        ('tracking', OrderedDict([
            ('flags', 0),
            ('timeslot', 0),
            ('longitude', Decimal('146.75968')),
            ('latitude', Decimal('-19.331072')),
            ('orientation', 0),
            ('activity', 0),
            ('battery', Decimal('3.00')),
            ('temp_min', Decimal('0.0')),
            ('temp_max', Decimal('20.0')),
            ('temp_alert', False),
            ('points',
             [
                 OrderedDict([
                     ('delta_km', 0),
                     ('delta_m', Decimal('234.3750')),
                     ('total_delta_m', Decimal('234.3750')),
                     ('delta_angle', Decimal('22.50000000')),
                     ('activity', 0), ('temp_alert', False),
                     ('latitude', -19.32912466132596),
                     ('longitude', 146.76053479568455)]),
                 OrderedDict([
                     ('delta_km', 0),
                     ('delta_m', Decimal('250.0000')),
                     ('total_delta_m', Decimal('250.0000')),
                     ('delta_angle', Decimal('338.90625000')),
                     ('activity', 0), ('temp_alert', False),
                     ('latitude', -19.3289743495036),
                     ('longitude', 146.75882251438833)]),
                 OrderedDict([
                     ('delta_km', 0),
                     ('delta_m', Decimal('390.6250')),
                     ('total_delta_m', Decimal('390.6250')),
                     ('delta_angle', Decimal('340.66406250')),
                     ('activity', 0),
                     ('temp_alert', False),
                     ('latitude', -19.32775718029063),
                     ('longitude', 146.75844736292584)
                 ])
             ])
        ]))]
    )),
    ('bch32', 0),
    ('crc16_verified', True),
    ('bch32_verified', True),
    ('decode_type', 'processed')
])