| Symptom | Likely Cause | Solution | |---------|--------------|----------| | Pairing succeeds, no COM port | Windows lacks JL-SPP driver | Install vendor’s INF driver | | Data corrupted or slow | Baud rate mismatch on UART | Match baud rate between JL chip and host MCU | | Connection drops after 30 sec | Power saving mode on JL chip | Disable deep sleep in firmware (if you have SDK access) | | “Driver not signed” error (Win 10/11) | JL’s INF lacks WHQL signature | Boot Windows with driver signature enforcement disabled, or use a signed generic SPP driver |
: Highly popular Bluetooth 5.0 chips with integrated audio codecs. jl-spp driver
: This stands for Serial Port Profile . It is a foundational Bluetooth configuration used to emulate a physical RS-232 serial cable connection over a wireless link, transferring raw data streams between your PC and the peripheral. | Symptom | Likely Cause | Solution |