Python if语句无法识别蓝牙信标

这是 BeaconScanner.py 文件用来查找和列出 ble 信标的 ScanUtility.py 文件。

#This is a working prototype. DO NOT USE IT IN LIVE PROJECTS


import sys
import struct
import bluetooth._bluetooth as bluez

OGF_LE_CTL=0x08
OCF_LE_SET_SCAN_ENABLE=0x000C

def hci_enable_le_scan(sock):
    hci_toggle_le_scan(sock, 0x01)

def hci_disable_le_scan(sock):
    hci_toggle_le_scan(sock, 0x00)

def hci_toggle_le_scan(sock, enable):
    cmd_pkt = struct.pack("<BB", enable, 0x00)
    bluez.hci_send_cmd(sock, OGF_LE_CTL, OCF_LE_SET_SCAN_ENABLE, cmd_pkt)

def packetToString(packet):
    """
    Returns the string representation of a raw HCI packet.
    """
    if sys.version_info > (3, 0):
    return ''.join('%02x' % struct.unpack("B", bytes([x]))[0] for x in packet)
    else:
    return ''.join('%02x' % struct.unpack("B", x)[0] for x in packet)

def parse_events(sock, loop_count=100):
    old_filter = sock.getsockopt( bluez.SOL_HCI, bluez.HCI_FILTER, 14)
    flt = bluez.hci_filter_new()
    bluez.hci_filter_all_events(flt)
    bluez.hci_filter_set_ptype(flt, bluez.HCI_EVENT_PKT)
    sock.setsockopt( bluez.SOL_HCI, bluez.HCI_FILTER, flt )
    results = []
    for i in range(0, loop_count):
    packet = sock.recv(255)
    ptype, event, plen = struct.unpack("BBB", packet[:3])
    packetOffset = 0
    dataString = packetToString(packet)
    """
    If the bluetooth device is an beacon then show the beacon.
    """
    #print (dataString)
    if dataString[34:50] == '0303aafe1516aafe' or '0303AAFE1116AAFE':
        """
        Selects parts of the bluetooth packets.
        """
        broadcastType = dataString[50:52]
        if broadcastType == '00' :
        type = "Eddystone UID"
        namespace = dataString[54:74].upper()
        instance = dataString[74:86].upper()
        resultsArray = [
        {"type": type, "namespace": namespace, "instance": instance}]
        return resultsArray

        elif broadcastType == '10':
        type = "Eddystone URL"
        urlprefix = dataString[54:56]
        if urlprefix == '00':
            prefix = 'http://www.'
        elif urlprefix == '01':
            prefix = 'https://www.'
        elif urlprefix == '02':
            prefix = 'http://'
        elif urlprefix == '03':
            prefix = 'https://'
        hexUrl = dataString[56:][:-2]
        url = prefix + hexUrl.decode("hex")
        rssi, = struct.unpack("b", packet[packetOffset -1])
        resultsArray = [{"type": type, "url": url}]
        return resultsArray

        elif broadcastType == '20':
        type = "Eddystone TLM"
        resultsArray = [{"type": type}]
        return resultsArray

        elif broadcastType == '30':
        type = "Eddystone EID"
        resultsArray = [{"type": type}]
        return resultsArray

        elif broadcastType == '40':
        type = "Eddystone RESERVED"
        resultsArray = [{"type": type}]
        return resultsArray

    if dataString[38:46] == '4c000215':
        """
        Selects parts of the bluetooth packets.
        """
        type = "iBeacon"
        uuid = dataString[46:54] + "-" + dataString[54:58] + "-" + dataString[58:62] + "-" + dataString[62:66] + "-" + dataString[66:78]
        major = dataString[78:82]
        minor = dataString[82:86]
        majorVal = int("".join(major.split()[::-1]), 16)
        minorVal = int("".join(minor.split()[::-1]), 16)
        """
        Organises Mac Address to display properly
        """
        scrambledAddress = dataString[14:26]
        fixStructure = iter("".join(reversed([scrambledAddress[i:i+2] for i in range(0, len(scrambledAddress), 2)])))
        macAddress = ':'.join(a+b for a,b in zip(fixStructure, fixStructure))
        rssi, = struct.unpack("b", packet[packetOffset -1])

        resultsArray = [{"type": type, "uuid": uuid, "major": majorVal, "minor": minorVal, "rssi": rssi, "macAddress": macAddress}]

        return resultsArray

    return results

原始的 Beaconscanner.py 文件通过列出信标来正常工作。

import ScanUtility
import bluetooth._bluetooth as bluez

#Set bluetooth device. Default 0.
dev_id = 0
try:
    sock = bluez.hci_open_dev(dev_id)
    print ("\n *** Looking for BLE Beacons ***\n")
    print ("\n *** CTRL-C to Cancel ***\n")
except:
    print ("Error accessing bluetooth")

ScanUtility.hci_enable_le_scan(sock)
#Scans for iBeacons
try:
    while True:
        returnedList = ScanUtility.parse_events(sock, 10)
        for item in returnedList:
            print(item)
            print("")
except KeyboardInterrupt:
    pass

这是修改后的 BeaconScanner.py 文件，如果扫描仪通过其 MAC 地址找到所需的信标，该文件应打印“Works”。

import ScanUtility
import bluetooth._bluetooth as bluez

#Set bluetooth device. Default 0.
dev_id = 0
try:
    sock = bluez.hci_open_dev(dev_id)
    print ("\n *** Looking for BLE Beacons ***\n")
    print ("\n *** CTRL-C to Cancel ***\n")
except:
    print ("Error accessing bluetooth")

ScanUtility.hci_enable_le_scan(sock)
#Scans for iBeacons
try:
    while True:
        returnedList = ScanUtility.parse_events(sock, 10)
        for macAddress in returnedList:
            if macAddress == "e2:e3:23:d1:b0:54":
            print("Works")
            else:
            print("Nope")
except KeyboardInterrupt:
    pass

然而，修改后的文件总是打印“Nope”。我认为 if 语句中的“macAddress”部分不能用于识别信标。必须在代码中更改哪些内容才能通过 if 语句中的 MAC 地址来识别信标？

根据消息来源ScanUtility.py，看起来该函数返回一个字典的列表，这有点奇怪。您应该按如下方式查询字典：

for item in returnedList:
    try:
        if item['macAddress'] == "e2:e3:23:d1:b0:54":
            print("Works")
        else:
            print("Nope")
    except KeyError:
        print('MAC Address is missing')

请注意，我添加了一个 try/ except 语句来处理以下情况：macAddress密钥不存在于您的字典中。仅当您的字典不是 defaultdict 的子类时，这才有效。