Merge pull request #1 from tannewt/lint

Lint

Author: jepler

README.rst

@@ -35,9 +35,6 @@ Installing from PyPI
 .. note:: This library is not available on PyPI yet. Install documentation is included
    as a standard element. Stay tuned for PyPI availability!
 
-.. todo:: Remove the above note if PyPI version is/will be available at time of release.
-   If the library is not planned for PyPI, remove the entire 'Installing from PyPI' section.
-
 On supported GNU/Linux systems like the Raspberry Pi, you can install the driver locally `from
 PyPI <https://pypi.org/project/adafruit-circuitpython-ble_midi/>`_. To install for current user:
 
@@ -63,7 +60,55 @@ To install in a virtual environment in your current project:
 Usage Example
 =============
 
-.. todo:: Add a quick, simple example. It and other examples should live in the examples folder and be included in docs/examples.rst.
+.. code-block:: python
+
+    """
+    This example sends MIDI out. It sends NoteOn and then NoteOff with a random pitch bend.
+    """
+
+    import time
+    import random
+    import adafruit_ble
+    from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
+    import adafruit_ble_midi
+    import adafruit_midi
+    from adafruit_midi.control_change import ControlChange
+    from adafruit_midi.note_off import NoteOff
+    from adafruit_midi.note_on import NoteOn
+    from adafruit_midi.pitch_bend import PitchBend
+
+    # Use default HID descriptor
+    midi_service = adafruit_ble_midi.MIDIService()
+    advertisement = ProvideServicesAdvertisement(midi_service)
+    # advertisement.appearance = 961
+
+    ble = adafruit_ble.BLERadio()
+    if ble.connected:
+        for c in ble.connections:
+            c.disconnect()
+
+    midi = adafruit_midi.MIDI(midi_out=midi_service, out_channel=0)
+
+    print("advertising")
+    ble.start_advertising(advertisement)
+
+    while True:
+        print("Waiting for connection")
+        while not ble.connected:
+            pass
+        print("Connected")
+        while ble.connected:
+            midi.send(NoteOn(44, 120))  # G sharp 2nd octave
+            time.sleep(0.25)
+            a_pitch_bend = PitchBend(random.randint(0, 16383))
+            midi.send(a_pitch_bend)
+            time.sleep(0.25)
+            # note how a list of messages can be used
+            midi.send([NoteOff("G#2", 120), ControlChange(3, 44)])
+            time.sleep(0.5)
+        print("Disconnected")
+        print()
+        ble.start_advertising(advertisement)
 
 Contributing
 ============

adafruit_ble_midi.py

@@ -39,87 +39,155 @@
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_BLE_MIDI.git"
 
+
 class _MidiCharacteristic(ComplexCharacteristic):
     """Endpoint for sending commands to a media player. The value read will list all available
 
        commands."""
+
     uuid = VendorUUID("7772E5DB-3868-4112-A1A9-F2669D106BF3")
 
     def __init__(self):
-        super().__init__(properties=Characteristic.WRITE_NO_RESPONSE | Characteristic.READ | Characteristic.NOTIFY,
-                         read_perm=Attribute.OPEN, write_perm=Attribute.OPEN,
-                         max_length=512,
-                         fixed_length=False)
+        super().__init__(
+            properties=Characteristic.WRITE_NO_RESPONSE
+            | Characteristic.READ
+            | Characteristic.NOTIFY,
+            read_perm=Attribute.ENCRYPT_NO_MITM,
+            write_perm=Attribute.ENCRYPT_NO_MITM,
+            max_length=512,
+            fixed_length=False,
+        )
 
     def bind(self, service):
         """Binds the characteristic to the given Service."""
         bound_characteristic = super().bind(service)
-        return _bleio.PacketBuffer(bound_characteristic,
-                                   buffer_size=4)
+        return _bleio.PacketBuffer(bound_characteristic, buffer_size=4)
+
 
 class MIDIService(Service):
+    """BLE MIDI service. It acts just like a USB MIDI PortIn and PortOut and can be used as a drop
+       in replacement.
+
+       BLE MIDI's protocol includes timestamps for MIDI messages. This class automatically adds them
+       to MIDI data written out and strips them from MIDI data read in."""
+
     uuid = VendorUUID("03B80E5A-EDE8-4B33-A751-6CE34EC4C700")
     _raw = _MidiCharacteristic()
+    # _raw gets shadowed for each MIDIService instance by a PacketBuffer. PyLint doesn't know this
+    # so it complains about missing members.
+    # pylint: disable=no-member
 
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
-        self._in_buffer = bytearray(self._raw.packet_length)
+        self._in_buffer = bytearray(self._raw.packet_size)
         self._out_buffer = None
         shared_buffer = memoryview(bytearray(4))
-        self._buffers = [None, shared_buffer[:1], shared_buffer[:2], shared_buffer[:3], shared_buffer[:4]]
+        self._buffers = [
+            None,
+            shared_buffer[:1],
+            shared_buffer[:2],
+            shared_buffer[:3],
+            shared_buffer[:4],
+        ]
         self._header = bytearray(1)
         self._in_sysex = False
         self._message_target_length = None
         self._message_length = 0
         self._pending_realtime = None
+        self._in_length = 0
+        self._in_index = 1
+        self._last_data = True
+
+    def readinto(self, buf, length):
+        """Reads up to ``length`` bytes into ``buf`` starting at index 0.
+
+           Returns the number of bytes written into ``buf``."""
+        i = 0
+        while i < length:
+            if self._in_index < self._in_length:
+                byte = self._in_buffer[self._in_index]
+                if self._last_data and byte & 0x80 != 0:
+                    # Maybe manage timing here. Not done now because we're likely slower than we
+                    # need to be already.
+                    # low_ms = byte & 0x7f
+                    # print("low", low_ms)
+                    self._in_index += 1
+                    self._last_data = False
+                    continue
+                self._in_index += 1
+                self._last_data = True
+                buf[i] = byte
+                i += 1
+            else:
+                if len(self._in_buffer) < self._raw.packet_size:
+                    self._in_buffer = bytearray(self._raw.packet_size)
+                self._in_length = self._raw.readinto(self._in_buffer)
+                if self._in_length == 0:
+                    break
+                # high_ms = self._in_buffer[0] & 0x3f
+                # print("high", high_ms)
+                self._in_index = 1
+                self._last_data = True
+
+        return i
 
     def read(self, length):
-        self._raw.read(self._in_buffer)
-        return None
+        """Reads up to ``length`` bytes and returns them."""
+        result = bytearray(length)
+        i = self.readinto(result, length)
+        return result[:i]
 
     def write(self, buf, length):
+        """Writes ``length`` bytes out."""
+        # pylint: disable=too-many-branches
         timestamp_ms = time.monotonic_ns() // 1000000
-        self._header[0] = (timestamp_ms >> 7 & 0x3f) | 0x80
+        self._header[0] = (timestamp_ms >> 7 & 0x3F) | 0x80
         i = 0
         while i < length:
             data = buf[i]
             command = data & 0x80 != 0
             if self._in_sysex:
-                if command: # End of sysex or real time
+                if command:  # End of sysex or real time
                     b = self._buffers[2]
-                    b[0] = 0x80 | (timestamp_ms & 0x7f)
-                    b[1] = 0xf7
-                    self._raw.write(b, self._header)
-                    self._in_sysex = data == 0xf7
+                    b[0] = 0x80 | (timestamp_ms & 0x7F)
+                    b[1] = 0xF7
+                    self._raw.write(b, header=self._header)
+                    self._in_sysex = data == 0xF7
                 else:
                     b = self._buffers[1]
                     b[0] = data
-                    self._raw.write(b, self._header)
+                    self._raw.write(b, header=self._header)
             elif command:
-                self._in_sysex = data == 0xf0
+                self._in_sysex = data == 0xF0
                 b = self._buffers[2]
-                b[0] = 0x80 | (timestamp_ms & 0x7f)
+                b[0] = 0x80 | (timestamp_ms & 0x7F)
                 b[1] = data
-                if 0xf6 <= data <= 0xff or self._in_sysex: # Real time, command only or start sysex
+                if (
+                    0xF6 <= data <= 0xFF or self._in_sysex
+                ):  # Real time, command only or start sysex
                     if self._message_target_length:
                         self._pending_realtime = b
                     else:
                         self._raw.write(b, self._header)
                 else:
-                    if 0x80 <= data <= 0xbf or 0xe0 <= data <= 0xef or data == 0xf2: # Two following bytes
+                    if (
+                        0x80 <= data <= 0xBF or 0xE0 <= data <= 0xEF or data == 0xF2
+                    ):  # Two following bytes
                         self._message_target_length = 4
                     else:
                         self._message_target_length = 3
                     b = self._buffers[self._message_target_length]
-                    # All of the buffers share memory so the timestamp and data have already been set.
+                    # All of the buffers share memory so the timestamp and data have already been
+                    # set.
                     self._message_length = 2
                     self._out_buffer = b
             else:
                 self._out_buffer[self._message_length] = data
                 self._message_length += 1
                 if self._message_target_length == self._message_length:
-                    self._raw.write(self._out_buffer, self._header)
-                    if _pending_realtime:
-                        self._raw.write(self._pending_realtime, self._header)
+                    self._raw.write(self._out_buffer, header=self._header)
+                    if self._pending_realtime:
+                        self._raw.write(self._pending_realtime, header=self._header)
                         self._pending_realtime = None
                     self._message_target_length = None
+            i += 1