def __init__(self, timeout=1.0, buffer_size=64):
"""Define the NUS service and start advertising it."""
self._nus_tx_char = Characteristic(self.NUS_TX_CHAR_UUID, notify=True)
self._nus_rx_char = Characteristic(self.NUS_RX_CHAR_UUID,
write=True,
write_no_response=True)
nus_uart_service = Service(self.NUS_SERVICE_UUID,
(self._nus_tx_char, self._nus_rx_char))
self._periph = Peripheral((nus_uart_service, ))
self._rx_buffer = CharacteristicBuffer(self._nus_rx_char,
timeout=timeout,
buffer_size=buffer_size)
def __init__(self, *, timeout=1.0, buffer_size=64, name=None):
self._read_char = Characteristic(NUS_RX_CHAR_UUID,
write=True,
write_no_response=True)
self._write_char = Characteristic(NUS_TX_CHAR_UUID, notify=True)
self._read_buffer = CharacteristicBuffer(self._read_char,
timeout=timeout,
buffer_size=buffer_size)
nus_uart_service = Service(NUS_SERVICE_UUID,
(self._read_char, self._write_char))
self._periph = Peripheral((nus_uart_service, ), name=name)
self._advertisement = ServerAdvertisement(self._periph)
class UARTServer:
"""
Provide UART-like functionality via the Nordic NUS service.
:param int timeout: the timeout in seconds to wait
for the first character and between subsequent characters.
:param int buffer_size: buffer up to this many bytes.
If more bytes are received, older bytes will be discarded.
Example::
from adafruit_ble.uart import UARTServer
uart = UARTServer()
uart.start_advertising()
# Wait for a connection.
while not uart.connected:
pass
uart.write('abc')
"""
NUS_SERVICE_UUID = UUID("6E400001-B5A3-F393-E0A9-E50E24DCCA9E")
NUS_RX_CHAR_UUID = UUID("6E400002-B5A3-F393-E0A9-E50E24DCCA9E")
NUS_TX_CHAR_UUID = UUID("6E400003-B5A3-F393-E0A9-E50E24DCCA9E")
def __init__(self, timeout=1.0, buffer_size=64):
"""Define the NUS service and start advertising it."""
self._nus_tx_char = Characteristic(self.NUS_TX_CHAR_UUID, notify=True)
self._nus_rx_char = Characteristic(self.NUS_RX_CHAR_UUID,
write=True,
write_no_response=True)
nus_uart_service = Service(self.NUS_SERVICE_UUID,
(self._nus_tx_char, self._nus_rx_char))
self._periph = Peripheral((nus_uart_service, ))
self._rx_buffer = CharacteristicBuffer(self._nus_rx_char,
timeout=timeout,
buffer_size=buffer_size)
def start_advertising(self):
"""Start advertising the service. When a client connects, advertising will stop.
When the client disconnects, restart advertising by calling ``start_advertising()`` again.
"""
self._periph.start_advertising()
def stop_advertising(self):
"""Stop advertising the service."""
self._periph.stop_advertising()
@property
def connected(self):
"""True if someone connected to the server."""
return self._periph.connected
def read(self, nbytes=None):
"""
Read characters. If ``nbytes`` is specified then read at most that many bytes.
Otherwise, read everything that arrives until the connection times out.
Providing the number of bytes expected is highly recommended because it will be faster.
:return: Data read
:rtype: bytes or None
"""
return self._rx_buffer.read(nbytes)
def readinto(self, buf, nbytes=None):
"""
Read bytes into the ``buf``. If ``nbytes`` is specified then read at most
that many bytes. Otherwise, read at most ``len(buf)`` bytes.
:return: number of bytes read and stored into ``buf``
:rtype: int or None (on a non-blocking error)
"""
return self._rx_buffer.readinto(buf, nbytes)
def readline(self):
"""
Read a line, ending in a newline character.
:return: the line read
:rtype: int or None
"""
return self._rx_buffer.readline()
@property
def in_waiting(self):
"""The number of bytes in the input buffer, available to be read."""
return self._rx_buffer.in_waiting
def reset_input_buffer(self):
"""Discard any unread characters in the input buffer."""
self._rx_buffer.reset_input_buffer()
def write(self, buf):
"""Write a buffer of bytes."""
# We can only write 20 bytes at a time.
offset = 0
while offset < len(buf):
self._nus_tx_char.value = buf[offset:offset + 20]
offset += 20