class FileTransferService(Service):
"""Simple (not necessarily fast) BLE file transfer service. It implements basic CRUD operations.
The server dictates data transfer chunk sizes so it can minimize buffer sizes on its end.
"""
uuid = StandardUUID(0xfebb)
version = Uint32Characteristic(uuid=FileTransferUUID(0x0100))
raw = _TransferCharacteristic()
# _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
# Actions
INVALID = 0x00
READ = 0x01
WRITE = 0x02
DELETE = 0x03
MKDIR = 0x04
LISTDIR = 0x05
# Responses
# 0x00 is INVALID
OK = 0x81
ERR = 0x82
ERR_NO_FILE = 0xb0
DIRECTORY = 0x01
def service_version_charac(cls, version=1):
"""Create a service_version Characteristic for use by a subclass."""
return Uint32Characteristic(
uuid=cls.adafruit_service_uuid(0x0002),
properties=Characteristic.READ,
write_perm=Attribute.NO_ACCESS,
initial_value=version,
)
class ButtonService(AdafruitService):
"""Status of buttons and switches on the board."""
uuid = AdafruitService.adafruit_service_uuid(0x600)
pressed = Uint32Characteristic(
uuid=AdafruitService.adafruit_service_uuid(0x601),
properties=(Characteristic.READ | Characteristic.NOTIFY),
read_perm=Attribute.OPEN,
write_perm=Attribute.NO_ACCESS,
)
"""
bit 0: slide switch: 1 for left; 0 for right
bit 1: 1 if button A is pressed
bit 2: 1 if button B is pressed
other bits are available for future buttons and switches
"""
measurement_period = AdafruitService.measurement_period_charac(0)
"""Initially 0: send notification only on changes. -1 means stop reading."""
def set_pressed(self, switch, button_a, button_b):
"""Update the pressed value all at once."""
pressed = 0
if switch:
pressed |= 0x1
if button_a:
pressed |= 0x2
if button_b:
pressed |= 0x4
if pressed != self.pressed:
self.pressed = pressed
@property
def switch(self):
"""``True`` when the slide switch is set to the left; ``False`` when to the right."""
return bool(self.pressed & 0x1)
@property
def button_a(self):
"""``True`` when Button A is pressed."""
return bool(self.pressed & 0x2)
@property
def button_b(self):
"""``True`` when Button B is pressed."""
return bool(self.pressed & 0x4)