struct.error: unpack requires a buffer of 2 bytes (ATCMiThermometer with Xiaomi beacon format)

[arepih]

Installed on RPi 4 and got error below after running a while: sudo aioblescan - m xx:xx:xx:xx:xx:xx Device is ATCMiThermometer with pvvx firmware v4.3 using Xiaomi beacon format (not ATC format) The reason I'm using Xiaomi beacon format beacuse I'm trying to get data from LYWSD03MMC thermometer both with older mi thermometer (circle shape with stock firmware which use Xiaomi beacon format).

Fatal error: protocol.data_received() call failed.
protocol: <aioblescan.aioblescan.BLEScanRequester object at 0xf7094c70>
transport: <_SelectorSocketTransport fd=6 read=polling write=<idle, bufsize=0>>
Traceback (most recent call last):
  File "/usr/lib/python3.9/asyncio/selector_events.py", line 870, in _read_ready__data_received
    self._protocol.data_received(data)
  File "/usr/local/lib/python3.9/dist-packages/aioblescan/aioblescan.py", line 1855, in data_received
    self.process(packet)
  File "/usr/local/lib/python3.9/dist-packages/aioblescan/__main__.py", line 51, in my_process
    xx = ev.decode(data)
  File "/usr/local/lib/python3.9/dist-packages/aioblescan/aioblescan.py", line 1303, in decode
    data = ev.decode(data)
  File "/usr/local/lib/python3.9/dist-packages/aioblescan/aioblescan.py", line 1350, in decode
    data = ev.decode(data)
  File "/usr/local/lib/python3.9/dist-packages/aioblescan/aioblescan.py", line 833, in decode
    data = field.decode(data)
  File "/usr/local/lib/python3.9/dist-packages/aioblescan/aioblescan.py", line 1379, in decode
    data = ad.decode(data)
  File "/usr/local/lib/python3.9/dist-packages/aioblescan/aioblescan.py", line 1649, in decode
    val.decode(data[: length.val - len(type)])
  File "/usr/local/lib/python3.9/dist-packages/aioblescan/aioblescan.py", line 664, in decode
    data = mynbyte.decode(data)
  File "/usr/local/lib/python3.9/dist-packages/aioblescan/aioblescan.py", line 623, in decode
    self.val = unpack(">%ds" % self.length, data[: self.length])[0][::-1]
struct.error: unpack requires a buffer of 2 bytes

[Ernst79]

How did you install HA? This error normally means that something is wrong with Bluetooth on the Pi or dongle. Either on hardware level, or on OS level.

[arepih]

I’m not using HA (Home assistant?). Actually someone open same issue previously struct.error: unpack requires a buffer of 2 bytes #40 and it was because the device use custom data structure so I thought maybe Xiaomi beacon format is not supported. I will try changing the thermometer to ATC beacon format and check if same error happen or not.

[Ernst79]

Ah, sorry, my mistake.

[arepih]

Changed to ATC format, same error. Move the sd card from rpi4 into rpi3B+, same error. Remove and reinsert battery from thermometer still error. Reboot the rpi, uninstall aioblescan then install again, finally no more error.