Some Qcc chips modules use same bottom plate , the difference is the chips on it .
● Module model: BTM321
● Bluetooth chip: QCC3021, the module built-in 32M SPI FLASH
● Bluetooth version: 5.1
● Module size: 13mm x 18mm x 2.5mm
● Power supply voltage: 3.0-4.3v
Default firmware:
1. Support sbc, aac decoding, no call function, optional I2S, analog output
2. Button description:
● SYS_CTRL: power on at high level, power off at low level, and automatically enter pairing mode after power on
● PIO2: Short press to play and pause, long press for 3 seconds to enter pairing, long press for 5 seconds to clear the pairing record
● PIO3: Short press the previous song, long press the volume to decrease
● PIO4: Short press a song, long press the volume to increase
● PIO5: connected to high level, not connected to low level
● PIO19: There is audio output high level, no audio low level
● PIO20: SPDIF output port
3. Indicator light description:
● Bluetooth is not connected: LED0 and LED1 flash alternately
● Bluetooth is connected: LED1 is always on
● Bluetooth audio playback: LED1 is always on
