Data Sheet

Bluegiga – A Silicon Labs Company 26

Host interface

8.1 UART

For applications where an external host such as MCU is used BT121 can be controlled over the UART

interface using the BGAPI

serial protocol.

For reliable communications can data transfer the hardware flow control RTS/CTS signals must be used in the

UART interface.

It is also recommended that the accuracy of the clock of the controlling host should be 1% or better for the

UART signaling to work reliably with speeds exceeding 115200 kbps (maximum baud rate is 4 Mbps).

Default UART settings are listed below:

Parameter

Default setting

UART baud rate

115200

RTS/CTS flow

control

Enabled

Data bits

Parity

None

Stop bits

Table 4 BT121 UART interface default settings