Python3環境，樹莓派使用bluepy與BLE設備通信

掃描設備

創建一個ScanDelegate

class ScanDelegate(DefaultDelegate):
    def __init__(self):
        DefaultDelegate.__init__(self)

    def handleDiscovery(self, dev, isNewDev, isNewData):
        if isNewDev:
            print("Discovered device", dev.addr)
        elif isNewData:
            print("Received new data from", dev.addr)

 

掃描設備並打印

scanner = Scanner().withDelegate(ScanDelegate())
devices = scanner.scan(10.0)
creyond_devices = []
for dev in devices:
    print("Device %s (%s), RSSI=%d dB" % (dev.addr, dev.addrType, dev.rssi))
    for (adtype, desc, value) in dev.getScanData():
        if value == "CreYond":
            creyond_devices.append(dev)
        print("  %s = %s" % (desc, value))

print(creyond_devices)

 

獲取Services與Characteristics

通過Peripheral來獲取Services

c_device = creyond_devices[0]
p_device = Peripheral(c_device)
p_device.withDelegate(NotifyDelegate(p_device))
services = p_device.getServices()

# displays all services
for service in services:
    print(service)

 

通過UUID獲取指定Service　　

service_uuid = UUID("00000010-3354-4d64-6e6f-XXXXXXX3534a")
c_service = p_device.getServiceByUUID(service_uuid)
print(c_service)

 

獲取Service下的Characteristics

characteristics = c_service.getCharacteristics()
# displays all characteristics
for char in characteristics:
    print(char)

 

訂閱與通知

創建一個NotifyDelegate

class NotifyDelegate(DefaultDelegate):
    # Constructor (run once on startup)
    def __init__(self, params):
        DefaultDelegate.__init__(self)

    # func is caled on notifications
    def handleNotification(self, cHandle, data):
        print("Notification from Handle: 0x" + format(cHandle,'02X') )
        print(hexlify(data))

在創建Peripheral時，指定

 p_device.withDelegate(NotifyDelegate(p_device)) 

查找descriptor，並設定其值為1.設定值時注意大小端 bytes([1, 0])。注意，直接寫characteristic是錯誤的，一定要找到characteristic下的UUID為0x2902的descriptor。部分藍牙設備的UUID可能不規范，通過UUID查找可能存在重復，建議getDescriptors篩選好對應范圍。

hEcg=notify_char.getHandle()
for descriptor in p_device.getDescriptors(hEcg,c_service.hndEnd):
    if (descriptor.uuid==0x2902):
        print(f'Client Characteristic Configuration found at handle 0x{format(descriptor.handle,"02X")}')
        hEcgCCC=descriptor.handle

p_device.writeCharacteristic(hEcgCCC,bytes([1, 0]))

等待顯示：

while True:
    if p_device.waitForNotifications(1.0):
        # handleNotification() was called
        continue

    print("Waiting... Waited more than one sec for notification")

 

完整代碼：

# %%
from bluepy.btle import Scanner, DefaultDelegate,UUID, Peripheral
from binascii import hexlify
import struct
# %%
class ScanDelegate(DefaultDelegate):
    def __init__(self):
        DefaultDelegate.__init__(self)

    def handleDiscovery(self, dev, isNewDev, isNewData):
        if isNewDev:
            print("Discovered device", dev.addr)
        elif isNewData:
            print("Received new data from", dev.addr)


class NotifyDelegate(DefaultDelegate):
    # Constructor (run once on startup)
    def __init__(self, params):
        DefaultDelegate.__init__(self)

    # func is caled on notifications
    def handleNotification(self, cHandle, data):
        print("Notification from Handle: 0x" + format(cHandle,'02X') )
        print(hexlify(data))


# %%
scanner = Scanner().withDelegate(ScanDelegate())
devices = scanner.scan(10.0)
creyond_devices = []
for dev in devices:
    print("Device %s (%s), RSSI=%d dB" % (dev.addr, dev.addrType, dev.rssi))
    for (adtype, desc, value) in dev.getScanData():
        if value == "CreYond":
            creyond_devices.append(dev)
        print("  %s = %s" % (desc, value))

print(creyond_devices)
# %% get services
# the first device name CreYond
c_device = creyond_devices[0]
p_device = Peripheral(c_device)
p_device.withDelegate(NotifyDelegate(p_device))
services = p_device.getServices()

# displays all services
for service in services:
    print(service)
# %% get specified service
service_uuid = UUID("00000010-3354-4d64-6e6f-xxxxxxxxx534a")
c_service = p_device.getServiceByUUID(service_uuid)
print(c_service)

# %%
characteristics = c_service.getCharacteristics()
# displays all characteristics
for char in characteristics:
    print(char)
# %% 
notify_char = characteristics[0]

#%%
hEcg=notify_char.getHandle()
for descriptor in p_device.getDescriptors(hEcg,c_service.hndEnd):
    if (descriptor.uuid==0x2902):
        print(f'Client Characteristic Configuration found at handle 0x{format(descriptor.handle,"02X")}')
        hEcgCCC=descriptor.handle

p_device.writeCharacteristic(hEcgCCC,bytes([1, 0]))

#%%
tmp_data=p_device.readCharacteristic(0x11)
print(tmp_data)
# %%
while True:
    if p_device.waitForNotifications(1.0):
        # handleNotification() was called
        continue

    print("Waiting... Waited more than one sec for notification")

# %%
p_device.disconnect()

# %%

 

 

參考鏈接：

【Bluetooth LE】Bluez中Bluetoothctl指令詳解（連接iPhone為例）

bluepy官方Demo

RPi Bluetooth LE

github demo