Bluetooth Audio Module
Ehong Technology Co., Ltd
UART_RX
Strong PU
UART_TX
Weak PU
UART_RTS
Weak PU
UART_CTS
Weak PD
SPI_MOSI
Weak PD
SPI_CLK
Weak PD
SPI_CSB
Strong PU
SPI_MISO
Weak PD
RESET
Strong PU
PIOs
Weak PD
PCM_IN
Weak PD
PCM_CLK
Weak PD
PCM_SYNC
Weak PD
PCM_OUT
Weak PD
QSPI_SRAM_CS
Strong PU
QSPI_FLASH_CS
Strong PU
QSPI_SRAM_CLK
Strong PD
QSPI_FLASH_CLK
Strong PD
Table 9: Pin Status on Reset
6.3. PIO
EH-MB18 has a total of 13digital programmable I/O terminals. They are powered from VDD .
Their functions depend on firmware running on the device. PIO lines can be configured through
software to have either weak or strong pull-ups or pull-downs.
Note:
All PIO lines are configured as inputs with weak pull-downs at reset.
Any of the PIO lines can be configured as interrupt request lines or as wake-up lines from sleep modes
.
6.4. AIO
EH-MB18 has 2 analogue I/O terminals. Their functions depend on software. Typically ADC
functions can be configured to battery voltage measurement. They can also be used as a digital
PIO.
6.5. RF interface
EH-MB18 internet chip antenna and U.fl port choose one of the ways. U.fl port external antenna,
impedance is 50 ohm.
6.6. UART
This is a standard UART interface for communicating with other serial devices. The UART
interface provides a simple mechanism for communicating with other serial devices using the
RS232 protocol.
