Wi-Fi&Bluetooth Module Series
FC905A_Hardware_Design 26 / 51
BT_CTS
BT_RTS
BT_RXD
BT_TXD
FC905A
UART_RXD
UART_TXD
UART_CTS
UART_RTS
HOST
Figure 6: Reference Design for UART Interface Connection
When paired with Quectel's LTE modules (EC21 series and EC25 series), it may be their own CTS
connected to CTS and RTS connected to RTS. This depends on the input and output directions, so in
principle, when connected, the input corresponds to the output.
3.6.2. BT_EN
BT_EN is used to control the Bluetooth function of FC905A. Bluetooth function will be enabled when
BT_EN is at high level.
Table 12: Pin Definition of BT_EN
3.6.3. BT_WAKE_HOST and HOST_WAKE_BT
BT_WAKE_HOST and HOST_WAKE_BT are used to wake up Bluetooth function.
Pin Name
Pin No.
I/O
Description
Comment
BT_EN
34
DI
Bluetooth enable control
Active high.
If unused, please pull it down.
VIO power domain.
NOTE