Capturing transducer Bluetooth output

I’m looking for a way to have HA record the pressure in our well pump tank over time, and found a Wireless Pressure Gauge that seems to work. I can see the transducer pressure via the iOS app from CirrusSense, but now need to figure out how to capture the data into HA.

The Raspberry Pi Bluetooth adapter appears in my device list, but I assume I have to create some sort of device or entity in order to listen for the data stream.

Has anyone figured out how to set up an unknown Bluetooth device for data logging?

Possible paths:

  1. ask the manufacturer for the bluetooth api documentation, this is the best for integration
  2. check the data communicated by the device with nRF Connect app and try to understand the logic
  3. (out of topic) cloud integration if they proposes a cloud api

The nRF app looks useful for investigating the BLE packets on the iOS device, but that’s not really where I need to see the data.

The place I’m stuck is how to discover and connect to the pressure sensor from Home Assistant on a Raspberry Pi 4.

Indeed, the nRF app is just a step for data understanding and asking developers for an HA integration so that you can get it working with your PI 4.
Alternatively, we could see the raw data with Theengs Gateway addon like below:

This way you can either share the BLE data and the sensor data (with different points), request its implementation, or try to decode the BLE data with YAML parsing.