BTM625 Bluetooth audio module, using CSRA64215 chip, support A2DP, AVRCP, HFP, TWS, AAC, I2S, APTX, APTX-LL et al., Using 4M SPI FLASH memory chips.
CSR Bluetooth audio module is a differential output, the need to increase the op amp or amp circuit is converted into a single-ended output (left channel, right channel, audio common).
Default program: do not take calls, analog audio output program.
Software Description:
Bluetooth name: BT Speaker
Key as follows:
PIN30 (MFB): high power, low power off (power-on modules, PIN30 need low, turn on the power to be done to delay circuit, not directly pull the boot automatically enters pairing mode)
PIN1 (PIO6): amplifier control enable pin (audio output, the output high 1.8V)
PIN2 (PIO8): Short press the play / pause / answer / hang up, press 1 seconds to reject a call
PIN3 (PIO1): short press to previous track, long press volume down
PIN4 (PIO0): short press to next track, long press volume up
Special Features:
PIN2: Press 3 seconds forced into pairing mode, press and hold 6 seconds to clear the pairing list
PIN2 + PIN3: Press 1 second to enter the search mode TWS
PIN2 + PIN4: Press 1 second to enter the mode being searched TWS
PIN3 + PIN4: Press 1 second off TWS