Add module and class level documentation

camrasdevices.py

+"""HPIB wrappers for devices in the Dwingeloo telescope
+
+This module contains some classes for conveniently working with the devices in the Dwingeloo
+Telescope that communicate over GPIB (General Purpuse Interface Bus) or HPIB (presumably the
+HP variant of GPIB). Currently, three of these devices exist, on different HPIB addresses:
+    * Receiver (address 1)
+    * Local Oscillator (address 28), used for mixing signals to downconvert them
+    * Clock Generator (address 14), used as the clock for the FPGA
+
+For each of the three devices a class exists. Setting and getting the frequency of these
+devices is done by using their `frequency` attribute.
+
+Example:
+    >>> import camrasdevices
+    >>> lo = LocalOscillator()
+    >>> lo.frequency
+    <Quantity 1.0 GHz>
+    >>> lo.frequency = 1.1e9
+    >>> lo.frequency
+    <Quantity 1.1 GHz>
+
+By default, the setter method of `frequency` checks if setting the device succeeded. This is a
+blocking operation, but the HPIB bus is quite fast.
+    >>> lo.frequency = 1.e18
+    Traceback (most recent call last):
+    RuntimeError: Setting frequency failed: tried to set to 1e+18 Hz, it is now 1100000000.0 Hz
+This checking can be disabled:
+    >>> non_checking_lo = camrasdevices.LocalOscillator(check_frequency = False)
+    >>> non_checking_lo.frequency = 1.e18
+    >>> non_checking_lo.frequency
+    <Quantity 1.1 GHz>
+
+The CamrasHpibDevice class spawns one thread (shared with all instances) to perform the HPIB
+commands. This is to make sure that instances living in separate threads do not interfere with
+each other. The thread is a daemon, so it will be killed on program exit.
+
+On initialization of the first CamrasDevice (or subclass), the command thread is initialized, and
+some initialization commands are sent to the HPIB bus to tell it to use the appropriate line
+endings etc.
+"""
+
 import astropy.units as u
 from astropy.units import Quantity
 

hpib.py

+"""Implementation of the GPIB protocol for use with serial.threading
+
+This class implements the GPIB (General Purpose Interface Bus) protocol following the example at
+https://github.com/pyserial/pyserial/blob/master/examples/at_protocol.py
+"""
+
 import serial.threaded
 import threading
 

track_doppler.py

+"""Doppler tracking functions by setting the local oscillator frequency over HPIB
+"""
+
 from typing import Any, Union
 
 import astropy.units as u
@@ -13,6 +16,19 @@ freq_hi = 1420.405751 * u.MHz
 
 
 def doppler_harm(sky_coordinate, time, tracking_frequency, location, variant):
+    """Return the doppler frequency by using the executables in Harm's home directory
+
+    Args:
+        sky_coordinate (SkyCoordinate): line of sight
+        time (Time): Astropy time object with time of the conversion
+        tracking_frequency (Quantity): frequency to track
+        location (EarthLocation): position of observatory (typically Dwingeloo)
+        variant (str): standard to use for the sun's movement: "bl" (IAU, based on Blaauw) for or
+            "mb" (Mihalas & Binney)
+
+    Returns:
+        Quantity: Doppler frequency
+    """
     ra = sky_coordinate.ra.to(u.rad).value
     dec = sky_coordinate.dec.to(u.rad).value
     t = time.unix