User's Guide

MP280B User’s Guide
8
4. AT Command
The string starting with "TTM" will be parsed and executed as an AT command, and
will be returned from the serial port as it is, and then the output execution result will be
added, "TTM:OK\r\n\0" or "TTM:ERP\r\n \0" and so on. Serial data packets that do not
begin with "TTM" will be considered transparent data.
4.1 Connection interval setting
Enter the following string into the serial port RX to set the BLE connection interval:
"TTM: CIT-Xms"
Where X="20", "30", "50", "100", "200", "300", "400", "500", "1000", "1500",
"2000", unit ms ( The above data formats are all ASCII code). For example, “TTM:
CIT-30ms” means that the connection interval is set to 30ms. After executing this
command, the following confirmation will be obtained from the serial port TX:
"TTM:TIMEOUT\r\n\0" indicates that the change timed out and the modification failed.
"TTM:OK\r\n\0" indicates that the change was successful and is running at the new
connection interval;
The success of this connection interval setting depends on the mobile device's limit
on the connection interval. Different IOS versions have different maximum connection
intervals. In addition, due to the internal mechanism of the BLE protocol, this instruction
will have different execution efficiency under different connection intervals.
Note: This connection interval is not saved when it is powered off, and the change
command is valid only after the connection is successful.
4.2 Get the module name
Enter the following string into the serial port RX:
"TTM:NAM-?"
Will receive from TX:
" TTM:NAM-xxxxxxxxxxxx\r\n\0"
The "xxxxxxxxxxxx" after the string is the Bluetooth module name.
4.3 Module rename
Input the following string to the serial port RX, where "Name" is the module name,
the length is within 16 bytes, and the ASCII code format.
" TTM:REN-" + Name
For example, "TTM: REN-ABC123" means to rename the module to "ABC123".
If the modification is successful, it will receive "TTM:OK\r\n\0" from TX. If the
command format is incorrect, it will return:
"TTM:ERP\r\n\0"
This name is saved after power down.
4.4 Get baud rate
Enter the following string into the serial port RX to set the baud rate: