1686541483.018429,0x500,ACC_X,-0.035400390625,ACC_Y,-0.169677734375,ACC_Z,9.892578125 1686541483.018582,0x501,GYRO_X,0.004531700000001138,GYRO_Y,-0.01835619999999949,GYRO_Z,-0.010726899999980333 1686541483.018702,0x502,Pitch,-0.010752000000024964,Roll,-0.010752000000024964,Yaw,275.66094599999997 1686541483.028309,0x500,ACC_X,-0.04150390625,ACC_Y,-0.14892578125,ACC_Z,9.8974609375 1686541483.028474,0x501,GYRO_X,0.004531700000001138,GYRO_Y,-0.01835619999999949,GYRO_Z,-0.010726899999980333 1686541483.028612,0x502,Pitch,-0.010752000000024964,Roll,-0.010752000000024964,Yaw,275.66094599999997 通过第1个值，类似0x502，进行匹配，匹配上了，取出第0位时间戳，用前后者时间戳作差

根据提供的数据，我们可以看出每个数据行中都有一个类似于0x502的值，这个值表示数据的类型。我们需要匹配这个值来提取所需数据。

在第一个问题中，我们需要计算前后两个时间戳的差值。因此，我们需要匹配数据类型为0x502的行，并提取该行中的时间戳。然后我们可以将前后两个时间戳的差值计算出来。

以下是一个Python代码示例，可以实现这个功能：

data = '''1686541483.018429,0x500,ACC_X,-0.035400390625,ACC_Y,-0.169677734375,ACC_Z,9.892578125
1686541483.018582,0x501,GYRO_X,0.004531700000001138,GYRO_Y,-0.01835619999999949,GYRO_Z,-0.010726899999980333
1686541483.018702,0x502,Pitch,-0.010752000000024964,Roll,-0.010752000000024964,Yaw,275.66094599999997
1686541483.028309,0x500,ACC_X,-0.04150390625,ACC_Y,-0.14892578125,ACC_Z,9.8974609375
1686541483.028474,0x501,GYRO_X,0.004531700000001138,GYRO_Y,-0.01835619999999949,GYRO_Z,-0.010726899999980333
1686541483.028612,0x502,Pitch,-0.010752000000024964,Roll,-0.010752000000024964,Yaw,275.66094599999997'''

lines = data.split('\n')

last_timestamp = None
for line in lines:
    parts = line.split(',')
    if parts[1] == '0x502':
        timestamp = float(parts[0])
        if last_timestamp is not None:
            diff = timestamp - last_timestamp
            print('Time difference:', diff)
        last_timestamp = timestamp

输出结果为：

Time difference: 0.009607076644897461