Add BLE support

[syssi]

Fixes #7

• [x] Record a btsnoop capture to get a better understanding of the BLE traffic
• [x] Identify available and used services, chars and handles
• [x] Subscribe to notifications
• [x] Request data periodically (0x03: cell info, 0x04: cell voltages)
• [x] Receive notifications and pass the data to the decoder

Available BLE services, chars and handles

Found device at MAC address [70:3E:97:07:C0:3E]
 Attempting BLE connection to 70:3e:97:07:c0:3e
 Service UUID: 0x1800
   start_handle: 0x1  end_handle: 0x7
  characteristic 0x2A00, handle 0x3, properties 0x12
  characteristic 0x2A01, handle 0x5, properties 0x2
  characteristic 0x2A04, handle 0x7, properties 0x2
 Service UUID: 0x1801
   start_handle: 0x8  end_handle: 0xb
  characteristic 0x2A05, handle 0xa, properties 0x20
 Service UUID: 0x180A
   start_handle: 0xc  end_handle: 0xe
  characteristic 0x2A50, handle 0xe, properties 0x2
 Service UUID: 0xFF00
   start_handle: 0xf  end_handle: 0x16
  characteristic 0xFF01, handle 0x11, properties 0x12
  characteristic 0xFF02, handle 0x15, properties 0x6
 Service UUID: 00010203-0405-0607-0809-0A0B0C0D1912
   start_handle: 0x17  end_handle: 0x1b
  characteristic 00010203-0405-0607-0809-0A0B0C0D2B12, handle 0x19, properties 0x6

Protocol details

Setup request

Subscribe notifications

Frame no. 50

• Write Request (0x12) Handle: 0x0012 Service: 0xff00 Characteristic: 0xff01 UUID: 0x2901 Payload: Enable notifications

  -> BMS does respond with a "Write response (0x13)"

Periodic requests

Query cell voltages (0x04)

Frame no. 52

• Write Command (0x52) Handle: 0x0015 Service: 0xff00 UUID: 0xff02 Payload: dda50400fffc77

Query cell info (0x03)

Frame no. 55

• Write Command (0x52) Handle: 0x0015 Service: 0xff00 UUID: 0xff02 Payload: dda50300fffd77

Notifications:

Cell info notification (0x03, 40 + 32 bytes)

Frame no. 56 + 57

• Handle Value Notification (0x1b) Handle: 0x0011 Service: 0xff00 Characteristic: 0xff01 Value: dd03001d055a00006d5e6d6000002c7c00000000[Frame2:]000080640304030b6e0b6e0b6afaef77

Cell voltages (0x04, 30 bytes)

Frame no. 66

• Handle Value Notification (0x1b) Handle: 0x0011 Service: 0xff00 Characteristic: 0xff01 Value: dd0400080d660d610d680d59fe3c77