A Node-Red BLE (Bluetooth Low Energy) central module. Uploading fork to test if it still works
sudo npm install @komodokodomo/node-red-contrib-ignoble
Create a scanner node. This does not run by itself - hook up a trigger to it!
Connect a peripheral node to the scanner node and configure it to your liking, or don't.
Connect a service node to the peripheral node. This node just transforms data. You need it.
Connect a characteristic node to the service node. This node will let you fish out characteristic data.
After the characteric node has run, msg.payload will contain its data - this can be shunted to other nodes like MQTT, Twitter or a debug node.
An example flow of two temperature sensors being polled every 30 minutes and characteristics exposed over Homebridge/MQTT. A third SHT21 sensor will push its temperature (2a6e) when the characteristic changes.
An example flow of subscribing to a peripheral's ccc5 characteristic. Set the peripheral's timeout to 0 and turn on the characteristic's subscribe flag to maintain notifications forever or until the device is disconnected.