With this alternative option one can send up to 512 bytes of data which is would fit most of the data in the iSpindle dataformat. The format will be customizable in the editor.
The gravitymon BLE sender will support 3 modes:
- Tilt (iBeacon broadcast with Gravity + Temperature)
- Tilt PRO (iBeacon broadcast with Gravity + Temperature, higher accuracy)
- Gravitymon (Service Characteristics with up to 512 bytes of data), requires a client to connect to the device to read data.
- Gravitymon Extended Advertisement (BLE5 Advertisement with up to 252 bytes of data), requires an active client to detect the data.
| Option | Passive Scan | Active Scan | Connect | ESP32 | Win/Python |
|---|---|---|---|---|---|
| iBeacon/Tilt | Yes | Yes | No | Yes | Yes |
| iBeacon/Tilt Pro | Yes | Yes | No | Yes | Yes |
| iBeacon/Gravmon | Yes | Yes | No | Yes | Yes |
| GravityMon - Service/Characteritics | Yes | Yes | Yes | Yes | Yes |
| GravityMon - Ext Advertisement | No | Yes | No | Yes | No |
| GravityMon - EddyStoneTLM | No | Yes | No | Yes | Yes |
| Option | Gravity | Temp | Angle | Battery | Interval | Name | Token | ChipID | RSSI |
|---|---|---|---|---|---|---|---|---|---|
| iBeacon/Tilt | Yes | Yes | - | - | - | - | - | - | - |
| iBeacon/Tilt Pro | Yes | Yes | - | - | - | - | - | - | - |
| iBeacon/GravityMon | Yes | Yes | Yes | Yes | - | - | - | Yes | - |
| GravityMon - Service/Characteritics | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | - |
| GravityMon - Ext Advertisement | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | - |
| GravityMon - EddyStoneTLM | Yes | Yes | Yes | Yes | - | - | - | Yes | - |
This option is under battery testing to see what benefits this will bring.
- Gravitymon will send out the BLE advertisement for up to 5 seconds (can be detected with both passive and active scanning)
- A client will connect to the device and read the characteristic which will be a json string (format will be configurable), we are limited to 512 bytes of data.
- Once the reading has been done or the timeout expires the gravitymon device will go into sleep mode.
Its expected to double the battery life for the device compared to sending the same data over wifi. More tests on coverage and distance is needed before this is implemented.
This option will send the data as part of an extended advertisement, this allows for up to 252 bytes of data.
Works with the esp32 client in this project but not with a Windows computer nor an iPhone.
This project contains the following targets
- server-tilt-c3 : Standard TILT beacon for esp32 c3 board
- server-tilt-ext-c3 : Standard TILT beacon for esp32 c3 board (with EXT advertising enabled)
- server-gravitymon-c3: Gravitymon BLE format for esp32 c3 board
- server-gravitymon-ext-c3: Gravitymon BLE format for esp32 c3 board (with EXT advertising enabled)
- server-adv-c3: Gravitymon BLE extended advertiserment for esp32 c3 board (with EXT advertising enabled)
- client-s3: Client that can connect and read both TILT beacon and Gravitymon advertisement
Gravitymon BLE format requires that the client connects on the server to read the data via a characteristics attribute (can be up to 512 chars). Works with client in PASSIVE or ACTIVE mode.
Gravitymon BLE ext advertising format requires that the is in ACTIVE mode. Here the payload is part of the advertisement (can be up to 252 chars)
The following defines are used:
CONFIG_BT_NIMBLE_EXT_ADV=1 Enabling this will configure the NimBLE library to support extended advertisement. When using this mode its possible to advertise a mix of data options, TILT + Gravitymon for instance.
The TILT beacon scanner code is based on Thorrak's TILTBRIDGE project. The TILT beacon is based on the tilt-sim by Spouliot
On a linux machine aioblescan can be used to detect tilt devices. Just run:
aioblescan --tilt
Tilt {"uuid": "a495bb10c5b14b44b5121370f02d74de", "major": 41, "minor": 1234, "tx_power": 0, "rssi": -60, "mac": "c8:c9:a3:cb:38:1a"}
If you first test with the tilt option you can find the MAC adress of the BLE chip which is useful to find the right device when testing with the gravitymon option.
python .\bleak_scan.py --address c8:c9:a3:cb:38:1a
or
python .\bleak_scan.py --name gravitymon
2023-10-21 12:32:07,877 __main__ INFO: [Service] 00001800-0000-1000-8000-00805f9b34fb (Handle: 1): Generic Access Profile
2023-10-21 12:32:07,905 __main__ INFO: [Characteristic] 00002a00-0000-1000-8000-00805f9b34fb (Handle: 2): Device Name (read), Value: bytearray(b'gravitymon')
2023-10-21 12:32:07,934 __main__ INFO: [Characteristic] 00002a01-0000-1000-8000-00805f9b34fb (Handle: 4): Appearance (read), Value: bytearray(b'\x00\x00')
2023-10-21 12:32:07,935 __main__ INFO: [Service] 00001801-0000-1000-8000-00805f9b34fb (Handle: 6): Generic Attribute Profile
2023-10-21 12:32:07,936 __main__ INFO: [Characteristic] 00002a05-0000-1000-8000-00805f9b34fb (Handle: 7): Service Changed (indicate)
2023-10-21 12:32:07,966 __main__ INFO: [Descriptor] 00002902-0000-1000-8000-00805f9b34fb (Handle: 9): Client Characteristic Configuration, Value: bytearray(b'\x02\x00')
2023-10-21 12:32:07,967 __main__ INFO: [Service] ea9a7e4b-d000-483d-8fdb-94b47730ed7a (Handle: 10): Unknown
2023-10-21 12:32:08,012 __main__ INFO: [Characteristic] ea9a7e4b-d100-483d-8fdb-94b47730ed7a (Handle: 11): Unknown (read), Value: bytearray(b'{"name":"my_device_name","ID": "01234567","token":"my_token","interval":46,"temperature":20.2,"temp_units":"C","gravity":1.05,"angle":
python .\scan.py