4.1 Bluetooth Low Energy Status Indication Pin 1 (PB3) and Pin 2 (PB7)

Use both pins to indicate Bluetooth Low Energy connection: Bluetooth Low Energy UART transparent service status and MCU DFU status.

Table 4-1. Status Indication
BT_Status_Ind1 (PB3)	BT_Status_Ind2 (PB7)	RNBD451 Status
Low	Low	Bluetooth® Low Energy is disconnected
Low	Low	Data transmission channel is closed
High	Low	Bluetooth Low Energy is connected
High	Low	Data transmission channel is closed
High	High	Bluetooth Low Energy is connected
High	High	Data transmission channel is opened
Low	High	MCU DFU mode (local or over OTAPC)

Note: By default, the Bluetooth Status Indication feature is disabled in the firmware. Enable this feature via SR, <hex16> command (SR,1000). For more details, refer to Set Application Options (SR,<hex16>).