4 ASCII Commands

Both the RN4678 and the RN4677 module have an ASCII command interface over the UART that is based on a similar command set. The RN4678 module is a successor to the RN4677 module; therefore, it has more features and improvements with respect to the RN4677 module. The list of the commands introduced in the RN4678 module in comparison with the RN4677 module are available in Table 4-2. Table 4-1 provides the list of RN4677 commands whose function changed in RN4678. Table 4-3 provides the list of the RN4677 commands that are no longer supported by the RN4678 module.

Refer to the following user guides to learn more about the commands listed below:

RN4678 Bluetooth® Dual Mode Module Command Reference User’s Guide (DS50002506)
RN4677 Bluetooth® 4.0 Dual Mode Module User’s Guide (DS50002377)

Table 4-1. List of the RN4677 Commands Whose Function/Settings Changed
Command	RN4677 Function	RN4678 Function
SQ,<H16>	Sets the data streaming reliability	Sets the features of the RN4678 module
ST,<H16>,<H16>,<H16>,<H16>	Sets the connection parameters	Sets the connection parameters. The RN4678 module has an additional connection parameter
SU,<H8>	Sets UART baud rate	Sets the UART baud rate. The parameter setting the baud rate is updated
GK	Displays current connection status	Displays current connection status. The functionality of values returned are updated
C<1-8>	Reconnect to previously connected device. The RN4677 module allows four devices	Reconnect to previously connected device. The RN4678 module allows eight devices
F[,<0-5>[,<hex>]]	Puts the module in Fast Data mode	Inquires Bluetooth® devices in the neighborhood
IS	Inquiry scan of other Microchip modules	Sets the scan response payload
X	Display configurations	Terminates a scan operation

Table 4-2. List of Commands Introduced in RN4678 Module
Command	Default	Function
SDM,<TXT>	RN4678	Sets the model string in the Bluetooth® Low Energy device information service
SDN,<TXT>	Microchip	Sets the manufacture string
SDR,<TXT>	Current RN4678 software version	Sets the software revision of the firmware
SDS,<TXT>	MAC address of the device	Sets the serial number of the device
SH,<0,1>	0	Enables low-power operation
SL,<H8>	02	Sets the duration of the Bluetooth classic and Bluetooth Low Energy scan operation
SX,<H8>,<H8>	—	Sets the functions of the individual pins
SZ,<0-1>	0	Controls the beacon-things feature
&,<Addr>	—	Assigns random address to local device
&C	—	Clears the random address
&R	—	Generates a resolvable random address
IA,<H8>,<Hex>/IB,<H8>,<Hex>/IS, <H8>,<Hex> NA,<H8>,<Hex>/NB,<H8>,<Hex>/NS, <H8>,<Hex>	—	Sets the advertisement, beacon and scan response payload format
JA,<Address>/JA,<0,1>,<Address>	—	Adds an address to the white list
JB	—	Adds all bonded devices to the white list
JC	—	Clears the white list
JD	—	Displays devices currently in the white list
U,<Z,1-8>	—	Removes the device from the linked device list

Table 4-3. List of RN4677 Commands Not Present in RN4678 Module
Command	Function	Suggested RN4678 Replacement
E	Display extended settings of the device	—
A	Starts the Bluetooth® Low Energy advertisement	—
CF,<address>	Connect to <address> and immediately go into Fast Data mode	Command: `SQ` Set Fast Data mode before using C command
CFR	Connect to stored remote address and immediately go into Fast Data mode	Command: `SQ` Set Fast Data mode before using C command
H	Help command: Displays basic list of commands	—
I,<value 1>,<value 2>	Perform an inquiry scan	Command: `F,0`
IL[,<H8>,<H16>,<H16>]	Scan for neighborhood Bluetooth Low Energy devices	Command: `F,5`
IN<value 1>,<value 2>	Inquiry scan without Bluetooth name	Command: `F,4`
IQ	Scans in pairing mode and returns RSSI	Command: `F,4`
IS	Inquiry scan of other Microchip modules	Command: `F,2,001F00`
IR	Inquiry scan based on Class of Device (COD)	Command: `F,2,0055AA`
N,<address>	Removes device from paired device list	—
O	Displays other settings	—
S>	Enable/disable command prompt	Command: `SQ` Enable/disable command prompt

Apple Support Improvements

As the RN4677, the RN4678 APL modules natively support the service profile required for iOS devices, the iPod Accessory Profile (iAP2) and the COD that allows the discovery and pairing with iOS devices in the Classic Bluetooth mode. To establish a Bluetooth link with an iOS device, the RN4678 needs to be connected to an Apple authentication co-processor via I²C lines.