RN4677 Bluetooth
®
4.0 Dual Mode Module User’s Guide
DS50002377A-page 12 2015 Microchip Technology Inc.
1.3 ACCESSING THE RN4677 OVER UART
A terminal emulator, such as Tera Term (Windows) or CoolTerm (Mac OS-X
®
), can be
used to control RN4677 from a computer.
With RN4677 connected to a computer and a serial port enumerated for the UART port,
run the terminal emulator to open the COM port with the following port settings:
• Baud rate 115,200 bps
•8 bits
•No Parity
• 1 stop bit
• Hardware flow control disabled
To enter Command mode, type $$$ into the terminal emulator. Once RN4677 enters
Command mode, the string CMD> must be sent to UART to indicate the start of
Command mode session. Once in Command mode, valid ASCII commands can be
issued to control or configure RN4677. All commands end with <cr> key (carriage
return <cr>), and are always responded by RN4677. The next command must not be
issued prior receiving a response to the previous command. For Set or Action
commands, the positive response is AOK and negative response is either ERR for error
or ? for unknown command. By default, when the RN4677 is ready to receive the next
command, the command prompt CMD> is sent to UART. Users can turn off this feature
by using command S> to ensure that the interface is backward compatible with
RN41/42/52/4020.
To return to Data mode, type ---<cr>. RN4677 automatically enters Data mode once
it connects or disconnects with another device.
1.4 OPERATING MODES
RN4677 has several operating modes that the user can set using the command SM.
• Slave mode (SM,0) - Default mode, in which other Bluetooth devices can
discover and connect to the module. Outbound connections can be initiated in this
mode.
• Master mode (SM,1) - In this mode, the RN4677 module is not discoverable. The
module makes a connection when a connection command C is received. Refer to
command C for possible parameters for establishing connections.
• Auto-Connect Master mode (SM,3) - In this mode, the module automatically
makes connections on power-up and reconnects when the connection is lost. In
this mode, RN4677 automatically enters Fast mode, same as issuing command
F,1, therefore $$$ cannot enter Command mode. If an address is not stored,
RN4677 automatically enters Master mode.
• Paring mode (SM,6) - In this mode, the module attempts to connect to the remote
device that matches the stored remote address. To set the remote address, use
command SR.
Note: The module supports Fast Data mode. In this mode, the module does not
enter Command mode even if it receives $$$. To enable Fast Data mode,
use command F,1.
Note: Any changes to the device configuration using the set S commands do not
take effect until the device is rebooted using the reboot command R,1 or
power cycle.
