118 lines
3.4 KiB
Python
118 lines
3.4 KiB
Python
# This example demonstrates a peripheral implementing the Nordic UART Service (NUS).
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import bluetooth
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from ble_advertising import advertising_payload
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from micropython import const
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_IRQ_CENTRAL_CONNECT = const(1)
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_IRQ_CENTRAL_DISCONNECT = const(2)
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_IRQ_GATTS_WRITE = const(3)
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_FLAG_WRITE = const(0x0008)
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_FLAG_NOTIFY = const(0x0010)
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_UART_UUID = bluetooth.UUID("6E400001-B5A3-F393-E0A9-E50E24DCCA9E")
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_UART_TX = (
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bluetooth.UUID("6E400003-B5A3-F393-E0A9-E50E24DCCA9E"),
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_FLAG_NOTIFY,
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)
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_UART_RX = (
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bluetooth.UUID("6E400002-B5A3-F393-E0A9-E50E24DCCA9E"),
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_FLAG_WRITE,
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)
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_UART_SERVICE = (
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_UART_UUID,
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(_UART_TX, _UART_RX),
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)
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# org.bluetooth.characteristic.gap.appearance.xml
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_ADV_APPEARANCE_GENERIC_COMPUTER = const(128)
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class BLEUART:
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def __init__(self, ble, name="mpy-uart", rxbuf=100):
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self._ble = ble
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self._ble.active(True)
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self._ble.irq(self._irq)
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((self._tx_handle, self._rx_handle),) = self._ble.gatts_register_services((_UART_SERVICE,))
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# Increase the size of the rx buffer and enable append mode.
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self._ble.gatts_set_buffer(self._rx_handle, rxbuf, True)
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self._connections = set()
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self._rx_buffer = bytearray()
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self._handler = None
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# Optionally add services=[_UART_UUID], but this is likely to make the payload too large.
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self._payload = advertising_payload(name=name, appearance=_ADV_APPEARANCE_GENERIC_COMPUTER)
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self._advertise()
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def irq(self, handler):
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self._handler = handler
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def _irq(self, event, data):
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# Track connections so we can send notifications.
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if event == _IRQ_CENTRAL_CONNECT:
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conn_handle, _, _ = data
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self._connections.add(conn_handle)
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elif event == _IRQ_CENTRAL_DISCONNECT:
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conn_handle, _, _ = data
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if conn_handle in self._connections:
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self._connections.remove(conn_handle)
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# Start advertising again to allow a new connection.
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self._advertise()
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elif event == _IRQ_GATTS_WRITE:
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conn_handle, value_handle = data
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if conn_handle in self._connections and value_handle == self._rx_handle:
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self._rx_buffer += self._ble.gatts_read(self._rx_handle)
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if self._handler:
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self._handler()
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def any(self):
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return len(self._rx_buffer)
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def read(self, sz=None):
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if not sz:
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sz = len(self._rx_buffer)
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result = self._rx_buffer[0:sz]
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self._rx_buffer = self._rx_buffer[sz:]
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return result
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def write(self, data):
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for conn_handle in self._connections:
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self._ble.gatts_notify(conn_handle, self._tx_handle, data)
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def close(self):
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for conn_handle in self._connections:
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self._ble.gap_disconnect(conn_handle)
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self._connections.clear()
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def _advertise(self, interval_us=500000):
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self._ble.gap_advertise(interval_us, adv_data=self._payload)
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def demo():
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import time
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ble = bluetooth.BLE()
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uart = BLEUART(ble)
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def on_rx():
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print("rx: ", uart.read().decode().strip())
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uart.irq(handler=on_rx)
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nums = [4, 8, 15, 16, 23, 42]
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i = 0
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try:
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while True:
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uart.write(str(nums[i]) + "\n")
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i = (i + 1) % len(nums)
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time.sleep_ms(1000)
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except KeyboardInterrupt:
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pass
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uart.close()
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if __name__ == "__main__":
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demo()
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