There's a Bluetooth RGB LED bulb + combined Bluetooth speaker which identifies itself in BT scan as "Chsmartbulb". Where bought, it was described as "BL08A".
There're many BT speaker bulbs on market, even cheaper than this, but:
- Majority are advertized as BT 2.x or 3.x.
- On a closer look, many such bulbs are actually just Bluetooth speakers, the bulb color is not controlled via BT (and thus smartphone), instead there's a standalone remote (usually an IR one).
"Chsmartbulb" was bought specifically on a promise to be BT 4, and having a smartphone app.
On arrival, the inspection showed:
- The bulb is indeed BT 4, specifically controller inside supports dual mode BT EDR/BLE.
- Despite that, the bulb color is controlled (by the app) using BT EDR, not BLE, specifically using the SPP service. (Speaker works over AVDTP (maybe A2DP) BT EDR only service, as expected).
- There are some BLE services are exposed, but as mentioned, the official app doesn't access them. The also look dummy: service UUIDs like 0x6666, 0x7777. The first has characteristic 0x8888, reading as array of bunch of 0x88 values, being written, it retains written value. The second has characteristic 0x8877, consisting of 0x77 with the similar behavior.
- Manufacturer is "CUBE TECHNOLOGIES" (0x03EE).
The repo contains BT communication capture on an Android phone, from enabling BT to connecting to bulb, changing colors among the main ones (red, green, blue), turning bulb on and off.
There's a script which sends sequences from the capture to bulb. Thanks to @acolytec3, color changing codes were found.