I'm hoping someone with a bit of experience with Bluetooth BLE devices might be able to help me out.
I've picked up a Bluetooth 12v Car Battery Monitor which uses the android/ios app called "BM2"
https://www.aliexpress.com/item/33004648736.html
I'd like to use a Raspberry Pi Zero W to pair with the device & receive the data to then pipe into Domoticz (MQTT etc).
I've been able to connect and receive some data but I'm not sure how to decode it.
On immediate connection with gattool, it receives a line of data once per second:
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pi@RPi-ZeroW:~ $ sudo gatttool -b 90:E2:02:35:30:8E -I
[90:E2:02:35:30:8E][LE]> connect
Attempting to connect to 90:E2:02:35:30:8E
Connection successful
Notification handle = 0x002e value: 66 5a aa e9 8c c9 af c4 7a 04 c3 ff 6f d4 a0 e2
Notification handle = 0x002e value: 74 04 ba 2b d0 de 7b 14 85 8b e0 93 a2 e2 cb 94
Notification handle = 0x002e value: ec 6c df 86 8c 9f 3e b2 29 5a 97 eb b8 57 51 b1
Notification handle = 0x002e value: 28 6e 9a 62 ec 58 8c c3 8e 79 a5 52 c3 68 f5 ee
Notification handle = 0x002e value: c2 c4 74 81 29 95 2f 49 9d fc 73 3c 50 ae 45 85
Notification handle = 0x002e value: 43 3b 00 17 2f c2 c3 6f ad 64 93 a8 94 33 31 e2
Notification handle = 0x002e value: 64 60 71 a7 f8 06 5d b4 91 06 20 26 5b 17 0b fe
Notification handle = 0x002e value: c5 0f 0d 0b fa 30 76 cc e2 4e d5 61 6c 70 e0 5b
Notification handle = 0x002e value: c1 3f e4 df ca 08 0c ff 19 87 df 23 dc 34 02 17
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[90:E2:02:35:30:8E][LE]> primary
attr handle: 0x0001, end grp handle: 0x000b uuid: 00001800-0000-1000-8000-00805f9b34fb
attr handle: 0x000c, end grp handle: 0x000f uuid: 00001801-0000-1000-8000-00805f9b34fb
attr handle: 0x0010, end grp handle: 0x0022 uuid: 0000180a-0000-1000-8000-00805f9b34fb
attr handle: 0x0023, end grp handle: 0x0033 uuid: 0000fff0-0000-1000-8000-00805f9b34fb
attr handle: 0x0034, end grp handle: 0xffff uuid: f000ffc0-0451-4000-b000-000000000000
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[90:E2:02:35:30:8E][LE]> characteristics
Notification handle = 0x002e value: cd 9c 72 23 3e 0b 55 81 5b d0 a6 1d dd 87 5c 88
handle: 0x0002, char properties: 0x02, char value handle: 0x0003, uuid: 00002a00-0000-1000-8000-00805f9b34fb
handle: 0x0004, char properties: 0x02, char value handle: 0x0005, uuid: 00002a01-0000-1000-8000-00805f9b34fb
handle: 0x0006, char properties: 0x0a, char value handle: 0x0007, uuid: 00002a02-0000-1000-8000-00805f9b34fb
handle: 0x0008, char properties: 0x08, char value handle: 0x0009, uuid: 00002a03-0000-1000-8000-00805f9b34fb
handle: 0x000a, char properties: 0x02, char value handle: 0x000b, uuid: 00002a04-0000-1000-8000-00805f9b34fb
handle: 0x000d, char properties: 0x20, char value handle: 0x000e, uuid: 00002a05-0000-1000-8000-00805f9b34fb
handle: 0x0011, char properties: 0x02, char value handle: 0x0012, uuid: 00002a23-0000-1000-8000-00805f9b34fb
handle: 0x0013, char properties: 0x02, char value handle: 0x0014, uuid: 00002a24-0000-1000-8000-00805f9b34fb
handle: 0x0015, char properties: 0x02, char value handle: 0x0016, uuid: 00002a25-0000-1000-8000-00805f9b34fb
handle: 0x0017, char properties: 0x02, char value handle: 0x0018, uuid: 00002a26-0000-1000-8000-00805f9b34fb
handle: 0x0019, char properties: 0x02, char value handle: 0x001a, uuid: 00002a27-0000-1000-8000-00805f9b34fb
handle: 0x001b, char properties: 0x02, char value handle: 0x001c, uuid: 00002a28-0000-1000-8000-00805f9b34fb
handle: 0x001d, char properties: 0x02, char value handle: 0x001e, uuid: 00002a29-0000-1000-8000-00805f9b34fb
handle: 0x001f, char properties: 0x02, char value handle: 0x0020, uuid: 00002a2a-0000-1000-8000-00805f9b34fb
handle: 0x0021, char properties: 0x02, char value handle: 0x0022, uuid: 00002a50-0000-1000-8000-00805f9b34fb
handle: 0x0024, char properties: 0x0a, char value handle: 0x0025, uuid: 0000fff1-0000-1000-8000-00805f9b34fb
handle: 0x0027, char properties: 0x02, char value handle: 0x0028, uuid: 0000fff2-0000-1000-8000-00805f9b34fb
handle: 0x002a, char properties: 0x08, char value handle: 0x002b, uuid: 0000fff3-0000-1000-8000-00805f9b34fb
handle: 0x002d, char properties: 0x10, char value handle: 0x002e, uuid: 0000fff4-0000-1000-8000-00805f9b34fb
handle: 0x0031, char properties: 0x02, char value handle: 0x0032, uuid: 0000fff5-0000-1000-8000-00805f9b34fb
handle: 0x0035, char properties: 0x1c, char value handle: 0x0036, uuid: f000ffc1-0451-4000-b000-000000000000
handle: 0x0039, char properties: 0x1c, char value handle: 0x003a, uuid: f000ffc2-0451-4000-b000-000000000000
I'm not sure where to go from here. Any help would be appreciated!