Logging
=======

The Driver Station saves 2 types of log files to disk (in ``C:\Users\Public\Documents\FRC\Log Files``)
for later viewing. A ``.dslog`` and a ``.dsevents``.

The log populates the list with any file ending with ``.dslog``, but the Driver Station helpfully names
them with the current date and time. (e.g. ``2018_04_22 23_39_25 Sun.dslog``)

.. _logging_dslog:

``.dslog``
----------

Stored in Big Endian

.. table::
   :widths: auto

   +---------+--------+--------------------------------+--------------------+
   | Field   | Length | Type                           | Comments           |
   +=========+========+================================+====================+
   | Header  | 20     | :ref:`Header <logging_header>` |                    |
   +---------+--------+--------------------------------+--------------------+
   | Entries | n      | :ref:`Entry <logging_entry>`   | Array of n entries |
   +---------+--------+--------------------------------+--------------------+

.. _logging_header:

Header
^^^^^^

.. table::
   :widths: auto

   +---------------------+--------+--------+-------------------------------------------------+
   | Field               | Length | Type   | Comments                                        |
   +=====================+========+========+=================================================+
   | Version             | 4      | uint32 |                                                 |
   +---------------------+--------+--------+-------------------------------------------------+
   | Unknown             | 4      |        |                                                 |
   +---------------------+--------+--------+-------------------------------------------------+
   | Timestamp           | 4      | uint32 | Seconds since 1904/1/1                          |
   +---------------------+--------+--------+-------------------------------------------------+
   | Fractional Seconds? | 1      | uint8  | Divide by 256 to get decimal part of timestamp? |
   +---------------------+--------+--------+-------------------------------------------------+
   | Unknown             | 7      |        |                                                 |
   +---------------------+--------+--------+-------------------------------------------------+

.. _logging_entry:

Entry
^^^^^

.. table::
   :widths: auto

   +---------------+--------+------------------------------+---------------+
   | Field         | Length | Type                         | Comments      |
   +===============+========+==============================+===============+
   | Trip Time     | 1      | uint8                        | `x / 15 = ms` |
   +---------------+--------+------------------------------+---------------+
   | Packet Loss % | 1      | uint8                        | `x * 4`       |
   +---------------+--------+------------------------------+---------------+
   | Battery       | 2      | Battery                      | `xx + yy/256` |
   +---------------+--------+------------------------------+---------------+
   | RoboRIO CPU % | 1      | uint8                        | `x / 2`       |
   +---------------+--------+------------------------------+---------------+
   | Trace         | 1      | :ref:`Trace <logging_trace>` |               |
   +---------------+--------+------------------------------+---------------+
   | CAN Percent   | 1      | uint8                        | `x / 2`       |
   +---------------+--------+------------------------------+---------------+
   | Wifi dB       | 1      | uint8                        | `x / 2`       |
   +---------------+--------+------------------------------+---------------+
   | Wifi Mb       | 1      | uint8                        |               |
   +---------------+--------+------------------------------+---------------+
   | Unknown       | 2      |                              |               |
   +---------------+--------+------------------------------+---------------+
   | PDP Stats     | 21     | :ref:`PDP <logging_pdp>`     |               |
   +---------------+--------+------------------------------+---------------+
   | Unknown       | 3      |                              |               |
   +---------------+--------+------------------------------+---------------+

.. _logging_trace:

Trace
^^^^^

.. table::
   :widths: auto

   +----------------+--------------+---------+
   | Field          | Mask         | Comment |
   +================+==============+=========+
   | Brownout       | ``x.......`` |         |
   +----------------+--------------+---------+
   | Watchdog       | ``.x......`` |         |
   +----------------+--------------+---------+
   | DS Teleop      | ``..x.....`` |         |
   +----------------+--------------+---------+
   | Unused         | ``...x....`` |         |
   +----------------+--------------+---------+
   | DS Disabled    | ``....x...`` |         |
   +----------------+--------------+---------+
   | Robot Teleop   | ``.....x..`` |         |
   +----------------+--------------+---------+
   | Robot Auton    | ``......x.`` |         |
   +----------------+--------------+---------+
   | Robot Disabled | ``.......x`` |         |
   +----------------+--------------+---------+

.. _logging_pdp:

PDP
^^^

Current for each PDP port is stored as 10 bits, (mostly) packed together. 0-5 are packed and padded into the first 64 bits, 6-11 are packed and padded into the next 64 bits, 12-15 are packed into the next 40 bits. Each of the 10 bit numbers is the current of the port * 8.

.. table::
   :widths: auto

   +--------------------+--------------------------+-------------+
   | Ports              | Bits                     | Total Bytes |
   +====================+==========================+=============+
   | 0, 1, 2, 3, 4, 5   | 60 bits + 4 padding      | 8 bytes     |
   +--------------------+--------------------------+-------------+
   | 6, 7, 8, 9, 10, 11 | 60 bits + 4 bits padding | 8 bytes     |
   +--------------------+--------------------------+-------------+
   | 12, 13, 14, 15     | 40 bits                  | 5 bytes     |
   +--------------------+--------------------------+-------------+

.. _logging_dsevent:

``.dsevent``
------------

TODO