Potential bugs in collision detection

[SJ-Fang23]

Hi, the on_collision method doesn't seem to function properly.
It was giving

"spherov2/commands/sensor.py", line 117, in __collision_detected_notify_helper
unpacked = struct.unpack('>3hB3hBL', packet.data)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
struct.error: unpack requires a buffer of 18 bytes

I changed it to ">3hB3hBh" and everything works again.

[SJ-Fang23]

I was using Sphero Bolt.

[XbzOnGit]

I met with the same problem and made the following modifications.

# 2 * (3 * 2 + 1) + 4 = 18.  
if(len(packet.data) < 18):
            packet = packet._replace(data=bytearray(18))

This also works.