BM2 Bluetooth battery logger

[roblomq]

For several years I use several bluetooth Car battery loggers. It would be very nice if these can also be implemented in this ble2mqtt because then I can add the battery devices to my Domoticz system and monitor them more active. The hard part is that I'm no programmer so I do not have the knowledge to implement this. Hoping somebody is willing to help me with this. There is already some related decoding info done, this can be found here.

[devbis]

I can add support but I need help on your end to test and report results

[roblomq]

That would be great! Of course I am willing to help. Just let me know what to do.

[devbis]

@roblomq can you please start with

pip3 install -U https://github.com/devbis/ble2mqtt/archive/refs/heads/add-bm2.zip --no-cache-dir --force-reinstall

and trying to run this version.

Add this chunk to your config to devices section and replace the MAC.

        {
            "address": "11:22:33:aa:bb:de",
            "type": "voltage_bm2"
        }

pip3 install pycryptodome maybe needed for cryptography if not installed.

Or, if you use docker, switch to add-bm2 branch and build the container.

[roblomq]

Did some testing today, the built seems to run ok

pi@P1-Logger:/home/ble2mqtt-add-bm2 $ docker build -t ble2mqtt:add-bm2 .
[+] Building 1886.8s (15/15) FINISHED
 => [internal] load .dockerignore                                                                                                                                                                    0.1s
 => => transferring context: 2B                                                                                                                                                                      0.0s
 => [internal] load build definition from Dockerfile                                                                                                                                                 0.1s
 => => transferring dockerfile: 871B                                                                                                                                                                 0.0s
 => [internal] load metadata for docker.io/library/python:3-slim                                                                                                                                     0.8s
 => [internal] load build context                                                                                                                                                                    0.1s
 => => transferring context: 4.00kB                                                                                                                                                                  0.1s
 => [app 1/5] FROM docker.io/library/python:3-slim@sha256:551c9529e77896518ac5693d7e98ee5e12051d625de450ac2a68da1eae15ec87                                                                          22.1s
 => => resolve docker.io/library/python:3-slim@sha256:551c9529e77896518ac5693d7e98ee5e12051d625de450ac2a68da1eae15ec87                                                                               0.1s
 => => sha256:551c9529e77896518ac5693d7e98ee5e12051d625de450ac2a68da1eae15ec87 1.65kB / 1.65kB                                                                                                       0.0s
 => => sha256:6b19ac75ce642650f8d176c1a22055eccf23930ea233f9d1da59b337b03fc0c5 1.37kB / 1.37kB                                                                                                       0.0s
 => => sha256:a67006f2980ba81890a0c8c08255fb0ce63841849c679c584bf03d2883d2f187 6.85kB / 6.85kB                                                                                                       0.0s
 => => sha256:fd66b5af2fde2bb5ebcf018c90e3ab76a3e7e61404fec824d9b9324679a1201f 11.23MB / 11.23MB                                                                                                     6.1s
 => => sha256:907205b8529d308141dcf426367aa7e8f07417b84a07ea3b3038cd51c66633ce 241B / 241B                                                                                                           0.4s
 => => sha256:379d71632777079b10cc8f38c4aab9021c538f4bb2674a0872890181813dcf8b 3.37MB / 3.37MB                                                                                                       2.0s
 => => extracting sha256:fd66b5af2fde2bb5ebcf018c90e3ab76a3e7e61404fec824d9b9324679a1201f                                                                                                            8.8s
 => => extracting sha256:907205b8529d308141dcf426367aa7e8f07417b84a07ea3b3038cd51c66633ce                                                                                                            0.0s
 => => extracting sha256:379d71632777079b10cc8f38c4aab9021c538f4bb2674a0872890181813dcf8b                                                                                                            4.3s
 => [app 2/5] RUN apt-get update &&     apt-get install bluez -y &&     apt-get clean                                                                                                              154.5s
 => [builder 2/6] RUN apt-get update &&     apt-get install gcc git -y &&     apt-get clean                                                                                                        192.5s
 => [builder 3/6] WORKDIR /usr/src/app                                                                                                                                                               0.5s
 => [builder 4/6] COPY . .                                                                                                                                                                           1.0s
 => [builder 5/6] RUN pip install --user --no-warn-script-location -r requirements.txt                                                                                                            1619.2s
 => [builder 6/6] RUN pip install --user --no-warn-script-location .                                                                                                                                21.1s
 => [app 3/5] COPY --from=builder /root/.local /root/.local                                                                                                                                          5.7s
 => [app 4/5] COPY ./docker_entrypoint.sh docker_entrypoint.sh                                                                                                                                       0.3s
 => [app 5/5] RUN chmod +x docker_entrypoint.sh                                                                                                                                                      1.9s
 => exporting to image                                                                                                                                                                              15.0s
 => => exporting layers                                                                                                                                                                             15.0s
 => => writing image sha256:3f94f3845ee9a312495c7ce97bcf7f90268b29961cc2fef5c678314ea4574982                                                                                                         0.0s
 => => naming to docker.io/library/ble2mqtt:add-bm2                                                                                                                                                  0.0s
WARNING: buildx: failed to read current commit information with git rev-parse --is-inside-work-tree

But when I start the container it crashes immediately and I get the following log.

Starting system message bus: dbus.

Starting system message bus: dbus.
Starting bluetooth: bluetoothd.
Traceback (most recent call last):
  File "/root/.local/bin/ble2mqtt", line 5, in <module>
    from ble2mqtt.__main__ import main
  File "/root/.local/lib/python3.11/site-packages/ble2mqtt/__main__.py", line 7, in <module>
    from ble2mqtt.ble2mqtt import Ble2Mqtt
  File "/root/.local/lib/python3.11/site-packages/ble2mqtt/ble2mqtt.py", line 14, in <module>
    from .devices.base import (BINARY_SENSOR_DOMAIN, CLIMATE_DOMAIN, COVER_DOMAIN,
  File "/root/.local/lib/python3.11/site-packages/ble2mqtt/devices/__init__.py", line 12, in <module>
    from .voltage_bm2 import BM2Voltage  # noqa: F401
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/root/.local/lib/python3.11/site-packages/ble2mqtt/devices/voltage_bm2.py", line 33, in <module>
    class VoltageTesterBM2(SubscribeAndSetDataMixin, Sensor):
  File "/root/.local/lib/python3.11/site-packages/ble2mqtt/devices/base.py", line 103, in __new__
    newclass.ACTIVE_CONNECTION_MODE is not None
AssertionError: VoltageTesterBM2 requires ACTIVE_CONNECTION_MODE to be set

[devbis]

Yes, that was my fault. I updated the commit, can you please rerun it? Probably you need to delete local branch and refetch remote one, I did forced push. Will avoid force pushed for this branch in the future

[roblomq]

It works!!

2023-05-21 14:53:58 INFO: [Blind_AM43_Zonnescherm_Voorraam] send state={'linkquality': None, 'battery': 100, 'illuminance': 37.5, 'cover': {'state': 'closed', 'position': 100}}
2023-05-21 14:54:05 INFO: [BM2_Battery_Monitor_BM2_Losse_accu] send state=SensorState(voltage=12.42)
2023-05-21 14:55:05 INFO: [BM2_Battery_Monitor_BM2_Losse_accu] send state=SensorState(voltage=12.41)

Also Domoticz does automatically create a device through MQTT autodiscovery.

The only thing is that my car is about 5m away and it doesn't pick up the battery monitor. I'm currently using a CSR4.0 do you think the range can be improved with another transceiver. If yes, do you have any advice for a good bluetooth receiver?

[devbis]

Great! I'll create some docs and make a release soon.

As for bluetooth receivers, I don't use them much. Probably a bigger antenna can help in your case or a dongle with big antenna. But I can't recommend any brand because I'm not aware of details.

[devbis]

Done in version 0.1.6