246 lines
8.2 KiB
Python
246 lines
8.2 KiB
Python
# This example finds and connects to a peripheral running the
|
|
# UART service (e.g. ble_simple_peripheral.py).
|
|
|
|
import bluetooth
|
|
import random
|
|
import struct
|
|
import time
|
|
import micropython
|
|
|
|
from ble_advertising import decode_services, decode_name
|
|
|
|
from micropython import const
|
|
|
|
_IRQ_CENTRAL_CONNECT = const(1)
|
|
_IRQ_CENTRAL_DISCONNECT = const(2)
|
|
_IRQ_GATTS_WRITE = const(3)
|
|
_IRQ_GATTS_READ_REQUEST = const(4)
|
|
_IRQ_SCAN_RESULT = const(5)
|
|
_IRQ_SCAN_DONE = const(6)
|
|
_IRQ_PERIPHERAL_CONNECT = const(7)
|
|
_IRQ_PERIPHERAL_DISCONNECT = const(8)
|
|
_IRQ_GATTC_SERVICE_RESULT = const(9)
|
|
_IRQ_GATTC_SERVICE_DONE = const(10)
|
|
_IRQ_GATTC_CHARACTERISTIC_RESULT = const(11)
|
|
_IRQ_GATTC_CHARACTERISTIC_DONE = const(12)
|
|
_IRQ_GATTC_DESCRIPTOR_RESULT = const(13)
|
|
_IRQ_GATTC_DESCRIPTOR_DONE = const(14)
|
|
_IRQ_GATTC_READ_RESULT = const(15)
|
|
_IRQ_GATTC_READ_DONE = const(16)
|
|
_IRQ_GATTC_WRITE_DONE = const(17)
|
|
_IRQ_GATTC_NOTIFY = const(18)
|
|
_IRQ_GATTC_INDICATE = const(19)
|
|
|
|
_ADV_IND = const(0x00)
|
|
_ADV_DIRECT_IND = const(0x01)
|
|
_ADV_SCAN_IND = const(0x02)
|
|
_ADV_NONCONN_IND = const(0x03)
|
|
|
|
_UART_SERVICE_UUID = bluetooth.UUID("6E400001-B5A3-F393-E0A9-E50E24DCCA9E")
|
|
_UART_RX_CHAR_UUID = bluetooth.UUID("6E400002-B5A3-F393-E0A9-E50E24DCCA9E")
|
|
_UART_TX_CHAR_UUID = bluetooth.UUID("6E400003-B5A3-F393-E0A9-E50E24DCCA9E")
|
|
|
|
|
|
class BLESimpleCentral:
|
|
def __init__(self, ble):
|
|
self._ble = ble
|
|
self._ble.active(True)
|
|
self._ble.irq(handler=self._irq)
|
|
|
|
self._reset()
|
|
|
|
def _reset(self):
|
|
# Cached name and address from a successful scan.
|
|
self._name = None
|
|
self._addr_type = None
|
|
self._addr = None
|
|
|
|
# Callbacks for completion of various operations.
|
|
# These reset back to None after being invoked.
|
|
self._scan_callback = None
|
|
self._conn_callback = None
|
|
self._read_callback = None
|
|
|
|
# Persistent callback for when new data is notified from the device.
|
|
self._notify_callback = None
|
|
|
|
# Connected device.
|
|
self._conn_handle = None
|
|
self._start_handle = None
|
|
self._end_handle = None
|
|
self._tx_handle = None
|
|
self._rx_handle = None
|
|
|
|
def _irq(self, event, data):
|
|
if event == _IRQ_SCAN_RESULT:
|
|
addr_type, addr, adv_type, rssi, adv_data = data
|
|
if adv_type in (_ADV_IND, _ADV_DIRECT_IND,) and _UART_SERVICE_UUID in decode_services(
|
|
adv_data
|
|
):
|
|
# Found a potential device, remember it and stop scanning.
|
|
self._addr_type = addr_type
|
|
self._addr = bytes(
|
|
addr
|
|
) # Note: addr buffer is owned by caller so need to copy it.
|
|
self._name = decode_name(adv_data) or "?"
|
|
self._ble.gap_scan(None)
|
|
|
|
elif event == _IRQ_SCAN_DONE:
|
|
if self._scan_callback:
|
|
if self._addr:
|
|
# Found a device during the scan (and the scan was explicitly stopped).
|
|
self._scan_callback(self._addr_type, self._addr, self._name)
|
|
self._scan_callback = None
|
|
else:
|
|
# Scan timed out.
|
|
self._scan_callback(None, None, None)
|
|
|
|
elif event == _IRQ_PERIPHERAL_CONNECT:
|
|
# Connect successful.
|
|
conn_handle, addr_type, addr, = data
|
|
if addr_type == self._addr_type and addr == self._addr:
|
|
self._conn_handle = conn_handle
|
|
self._ble.gattc_discover_services(self._conn_handle)
|
|
|
|
elif event == _IRQ_PERIPHERAL_DISCONNECT:
|
|
# Disconnect (either initiated by us or the remote end).
|
|
conn_handle, _, _, = data
|
|
if conn_handle == self._conn_handle:
|
|
# If it was initiated by us, it'll already be reset.
|
|
self._reset()
|
|
|
|
elif event == _IRQ_GATTC_SERVICE_RESULT:
|
|
# Connected device returned a service.
|
|
conn_handle, start_handle, end_handle, uuid = data
|
|
print("service", data)
|
|
if conn_handle == self._conn_handle and uuid == _UART_SERVICE_UUID:
|
|
self._start_handle, self._end_handle = start_handle, end_handle
|
|
|
|
elif event == _IRQ_GATTC_SERVICE_DONE:
|
|
# Service query complete.
|
|
if self._start_handle and self._end_handle:
|
|
self._ble.gattc_discover_characteristics(
|
|
self._conn_handle, self._start_handle, self._end_handle
|
|
)
|
|
else:
|
|
print("Failed to find uart service.")
|
|
|
|
elif event == _IRQ_GATTC_CHARACTERISTIC_RESULT:
|
|
# Connected device returned a characteristic.
|
|
conn_handle, def_handle, value_handle, properties, uuid = data
|
|
if conn_handle == self._conn_handle and uuid == _UART_RX_CHAR_UUID:
|
|
self._rx_handle = value_handle
|
|
if conn_handle == self._conn_handle and uuid == _UART_TX_CHAR_UUID:
|
|
self._tx_handle = value_handle
|
|
|
|
elif event == _IRQ_GATTC_CHARACTERISTIC_DONE:
|
|
# Characteristic query complete.
|
|
if self._tx_handle is not None and self._rx_handle is not None:
|
|
# We've finished connecting and discovering device, fire the connect callback.
|
|
if self._conn_callback:
|
|
self._conn_callback()
|
|
else:
|
|
print("Failed to find uart rx characteristic.")
|
|
|
|
elif event == _IRQ_GATTC_WRITE_DONE:
|
|
conn_handle, value_handle, status = data
|
|
print("TX complete")
|
|
|
|
elif event == _IRQ_GATTC_NOTIFY:
|
|
conn_handle, value_handle, notify_data = data
|
|
if conn_handle == self._conn_handle and value_handle == self._tx_handle:
|
|
if self._notify_callback:
|
|
self._notify_callback(notify_data)
|
|
|
|
# Returns true if we've successfully connected and discovered characteristics.
|
|
def is_connected(self):
|
|
return (
|
|
self._conn_handle is not None
|
|
and self._tx_handle is not None
|
|
and self._rx_handle is not None
|
|
)
|
|
|
|
# Find a device advertising the environmental sensor service.
|
|
def scan(self, callback=None):
|
|
self._addr_type = None
|
|
self._addr = None
|
|
self._scan_callback = callback
|
|
self._ble.gap_scan(2000, 30000, 30000)
|
|
|
|
# Connect to the specified device (otherwise use cached address from a scan).
|
|
def connect(self, addr_type=None, addr=None, callback=None):
|
|
self._addr_type = addr_type or self._addr_type
|
|
self._addr = addr or self._addr
|
|
self._conn_callback = callback
|
|
if self._addr_type is None or self._addr is None:
|
|
return False
|
|
self._ble.gap_connect(self._addr_type, self._addr)
|
|
return True
|
|
|
|
# Disconnect from current device.
|
|
def disconnect(self):
|
|
if not self._conn_handle:
|
|
return
|
|
self._ble.gap_disconnect(self._conn_handle)
|
|
self._reset()
|
|
|
|
# Send data over the UART
|
|
def write(self, v, response=False):
|
|
if not self.is_connected():
|
|
return
|
|
self._ble.gattc_write(self._conn_handle, self._rx_handle, v, 1 if response else 0)
|
|
|
|
# Set handler for when data is received over the UART.
|
|
def on_notify(self, callback):
|
|
self._notify_callback = callback
|
|
|
|
|
|
def demo():
|
|
ble = bluetooth.BLE()
|
|
central = BLESimpleCentral(ble)
|
|
|
|
not_found = False
|
|
|
|
def on_scan(addr_type, addr, name):
|
|
if addr_type is not None:
|
|
print("Found peripheral:", addr_type, addr, name)
|
|
central.connect()
|
|
else:
|
|
nonlocal not_found
|
|
not_found = True
|
|
print("No peripheral found.")
|
|
|
|
central.scan(callback=on_scan)
|
|
|
|
# Wait for connection...
|
|
while not central.is_connected():
|
|
time.sleep_ms(100)
|
|
if not_found:
|
|
return
|
|
|
|
print("Connected")
|
|
|
|
def on_rx(v):
|
|
print("RX", v)
|
|
|
|
central.on_notify(on_rx)
|
|
|
|
with_response = False
|
|
|
|
i = 0
|
|
while central.is_connected():
|
|
try:
|
|
v = str(i) + "_"
|
|
print("TX", v)
|
|
central.write(v, with_response)
|
|
except:
|
|
print("TX failed")
|
|
i += 1
|
|
time.sleep_ms(400 if with_response else 30)
|
|
|
|
print("Disconnected")
|
|
|
|
|
|
if __name__ == "__main__":
|
|
demo()
|