How data is retrieved from the sensors?

eschava / node-red-contrib-xiaomi-ble

Xiaomi Bluetooth4 (BLE) sensors

MIT License

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How data is retrieved from the sensors? #12

Open 0xgrm opened 5 years ago

0xgrm commented 5 years ago

Hi,

I'd want to know if the values are red passively from the sensors or if the plugin explicitly connect to them for updating values.

Thanks.

eschava commented 5 years ago

Plugin connects to sensors and requests data from them

0xgrm commented 5 years ago

Is there a way you could possibly scan the data passively, as in the homebridge hygrothermograph plugin?

eschava commented 5 years ago

Sorry, what do you mean by "passively"? AFAIS, Homebridge uses similar code for requesting data from sensors

0xgrm commented 5 years ago

By passively, I mean not to connect to the BLE devices. Just:

Scan for BLE devices.
Check the broadcast advertisement packet.
Look for the Service Data UUID to check the sensor type and all data.

By doing this, there is no need to connect directly to the BLE devices, thus greatly improve efficiency and battery life of the sensors. I unfortunately don't have the skills to do it correctly.

eschava commented 5 years ago

I like the idea and have found this information at the link you mentioned OK, will try to implement this as an additional option at the nearest time

0xgrm commented 5 years ago

Glad you find this interesting! This is by far the best method but only the homebridge plugin I mentioned seems to do it, and only for the temperature sensors, not MiFlora.

Please let me informed of your avancements here. Me and a friend would love to try and help you add this functionality.

sjroe commented 4 years ago

@uryupinsk I've implemented a pair of nodes that do it in this manner:

node-red-contrib-ble-scan - this is a generic noble based node that simply continuously scans and presents the discovered peripherals as the msg.payload
node-red-contrib-mijia-filter - this utilises the parser from the homebridge-mi-hygrothermograph plugin that you referenced to present the broadcast package in the msg.payload

Simply link the above two nodes. In my flows I then have the output of the filter node going into a switch node to split the outputs by MAC address.

dingausmwald commented 2 years ago

This has never been implemented, right? Passive scan is much more battery friendly.