Hi all,
I have developed a Homey app for Senso4s BLE gas cylinder sensors.
You can find more details about those useful devices on manufacturer site - https://senso4s.com/
The goal is simple: make the gas level of your cylinder available in Homey, so you can use it in Flows, alerts and dashboards. Typical use cases are barbecue gas bottles, caravans, campers, outdoor kitchens or any place where running out of gas is inconvenient.
What the app can do
The app reads Senso4s BLE data and exposes it in Homey, including:
- Gas level in %
- Estimated gas remaining in kg
- Battery level
- Tank empty alarm
- Calibration needed alarm
- Device error alarm
- RSSI / signal strength
- Update method, for example
AdvertisementsorActive read - Gas level change and hourly gas usage estimate
- For Senso4s Plus: motion / inclination / temperature anomaly flags when advertised by the device
Important setup steps
Before adding the device to Homey, first configure the Senso4s sensor using the official Senso4s mobile app:
- iOS: Senso4s App - App Store
- Android: https://play.google.com/store/apps/details?id=com.companyname.Senso4sProject
Use the mobile app to set up the appliance / cylinder type and calibrate the sensor properly.
After that:
- Fully close / kill the Senso4s mobile app.
- Add the Senso4s device in Homey.
- Keep the sensor reasonably close to Homey during pairing and first read.
- Wait for updates.
- Move the cylinder/sensor to its final location.
The mobile app should be closed because BLE devices often allow only one active connection at a time.
Low RSSI / weak signal
The app is designed to work even with weak BLE signal.
Senso4s broadcasts useful state in BLE advertisements. Homey can receive those advertisements without actively connecting to the device. This means the app can still update important values even when the signal is too weak for a stable direct BLE connection.
Data available from advertisements includes mainly:
- Gas level %
- Battery %
- Model indication, Basic or Plus
- Usage mode
- Error / calibration / anomaly flags where available
- MAC/device identity
- RSSI
Data that requires a closer active BLE connection includes:
- Direct characteristic read
- Device configuration, including gas capacity / cylinder setup
- Setup date and similar GATT-only details
So if your device is far away and Homey shows Advertisements as the update method, that is expected and usually fine. The most important operational values still update from advertisements.
Cylinder capacity and kg calculation
The Senso4s advertisement contains the gas level as a percentage. To calculate remaining gas in kg, Homey needs to know the gas capacity of the cylinder.
When the device is close enough for an active BLE read, Homey can read the configured gas capacity from the Senso4s device and update the Homey setting automatically.
If the device is only reachable through advertisements, please check the Homey device settings and set the gas capacity manually.
Common cylinder sizes:
| Size | Empty weight | Gas capacity |
|---|---|---|
| 5 kg | 5-7 kg | 5 kg |
| 11 kg | 10-12 kg | 11 kg |
| 15 kg | 14-16 kg | 15 kg |
| 33 kg | 28-32 kg | 33 kg |
The empty cylinder weight is mainly part of the Senso4s calibration/setup in the official mobile app. Homey uses the gas capacity to calculate remaining gas from the advertised percentage.
Example Flows
Some useful Homey Flow ideas:
- If gas level drops below 20%, send a phone notification so the barbecue is not ruined halfway through cooking.
- If gas level is below a threshold, announce it on a smart speaker.
- When arriving with a caravan, Homey receives the Senso4s advertisement and can warn you automatically if the gas bottle is nearly empty.
- Track gas usage over time using the gas level change / hourly change capabilities.
Notes
Senso4s Basic does not have temperature, inclination or motion sensing. Those capabilities are only relevant for Senso4s Plus.
If your sensor is placed far away from Homey, keep an eye on the RSSI value. Advertisement-based updates can still work at low RSSI, but a close connection may be needed once to read or refresh the device configuration.
