IoTのアプリケーションを作る場合、顧客から指定をうけたBLEセンサーのデータを受信するケースがありますが、BLEセンサーのMACアドレスを確認することができないケースがあります。
Node-REDでBLEを受信する場合は、BLE BeaconScannerを使っていますが、事務所空間には数多くのBLEデータが飛び交っているので、その中から該当のBLEセンサーデータを見つけるのはけっこう大変です。
そこで、BLEデータのデータ長でフィルタリングをかけMACアドレスの一覧を作成することができれば、あとはWireSharkを使ってManufactureIDを確認するという作業も大幅に楽になります。
この記事ではそのやり方を紹介いたします。
Node-REDのフロー
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まずは、こちらのフローでBLE信号を受信、データの長さをLENというデータに格納。
MACアドレスを調べたいBLEセンサーのデータの長さを、おおよそ絞り込み、該当するMACアドレスの重複を削除した一覧をuniqueIdsとしてflowに保存します。
ID初期化はflowのuniqueIdsを初期化。
MAC出力はuniqueIdsの一覧を出力します。
WireSharkで確認
先に取得したMACアドレス一覧を、WireSharkのadvertising addressでフィルタリングします。
btle.advertising_address == c5:a2:65:80:b7:56
WireShark側の設定は下記記事を参照。
ABLIC社のバッテリレス漏水センサCLEAN-BoostのデータをNode-REDで受信する方法 – スマートライト株式会社
表示されたデータのManufactureIDを確認し、探しているBLEセンサーであれば成功。
もし違う場合は、別のMACアドレスで同じことをしてManufactureIDを確認します。