python - 使用 bluepy 委托(delegate)启用指示

Question

我能够在 bluepy 中遍历 BLE 设备的服务和特征，但无法获取要打印的异步指示。我查看了此question中的建议，但我无法让它工作。

使用 gattool 时它确实有效:

$ sudo gatttool -b "DF:01:93:A9:86:FF" -t random  --char-write-req --handle=0x002c --value=0200 --listen
Characteristic value was written successfully
Indication   handle = 0x002b value: 00 8a 00 
Indication   handle = 0x002b value: 00 8a 00 
Indication   handle = 0x002b value: 30 30 2d

但我无法让 bluepy 做同样的事情:

from bluepy.btle import Scanner, DefaultDelegate, Peripheral, ADDR_TYPE_RANDOM

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

    def handleNotification(self, cHandle, data):
        print "  got data: 0x%x" % data

periph = Peripheral('df:01:93:a9:86:ff', addrType=ADDR_TYPE_RANDOM)
periph.setDelegate(ReadCharacteristicDelegate())
periph.writeCharacteristic(0x002c, "\0x02\0x00")
print "Enabled indications"
while True:
    if periph.waitForNotifications(3.0):
        # handleNotification() was called
        continue
    print("Waiting")

它运行，但没有打印出任何指示:

$ sudo python simple.py 
Enabled indications
Waiting
Waiting

Answer 1

我发现了这个问题。 writeCharacteristic() 调用中存在拼写错误。显然这些字节中不应有前导“0”。修复此问题后，还必须更新数据打印回调以处理传入的 3 字节数据。现在可以使用:

from bluepy.btle import Scanner, DefaultDelegate, Peripheral, ADDR_TYPE_RANDOM
from struct import unpack

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

    def handleNotification(self, cHandle, data):
        print "got handle: 0x%x  data: 0x%x" % (cHandle, unpack('>i','\x00'+data)[0])

periph = Peripheral('df:01:93:a9:86:ff', addrType=ADDR_TYPE_RANDOM)
periph.setDelegate(ReadCharacteristicDelegate())
periph.writeCharacteristic(0x002c, b"\x02\x00")
print "Enabled indications"
while True:
    if periph.waitForNotifications(3.0):
        # handleNotification() was called
        continue
    print("Waiting")