7.3.1 Creating Custom GATT Services

To create a private GATT service, enter the following configuration commands:

Power on the RNBD350 module by connecting the RNBD350 Add On Board using a USB Type-C cable to the host PC.
Using the terminal emulator (TeraTerm), open the COM port associated with the RNBD350 module with the following settings.
Go to Setup>Terminal.
Under the New-line section, select CR+LF (Carriage Return, Line Feed) from the drop-down lists for better reading of data.
Figure 7-21. TeraTerm Serial Port Setup
Figure 7-22. TeraTerm Terminal Setup
Enter into Command mode:
1. Type the Command mode sequence $$$ to enter the Command mode.
2. Enter + to turn on ECHO.
Set to factory default:
1. Enter SF,2 and verify the module is rebooted after entering the command.
2. Type the command mode sequence $$$ to enter Command mode.
Note: Use this command only to remove previously configured services and characteristics and to bring the device to a factory Reset.
Create the private GATT service with three characteristics by entering the following command:
```
PS,4D6963726F636869702D524E34383730
PC,BF3FBD80063F11E59E690002A5D5C501,02,02
PC,BF3FBD80063F11E59E690002A5D5C502,08,02
PC,BF3FBD80063F11E59E690002A5D5C503,18,04
```
Figure 7-23. PS and PC Command
- The PS command creates the GATT private service, identified by UUID 16-byte value 4D6963726F636869702D524E34383730.
- The PC command creates the characteristics in the service. Each characteristic is identified by the following UUIDs:
  - BF3FBD80063F11E59E690002A5D5C501, BF3FBD80063F11E59E690002A5D5C502, BF3FBD80063F11E59E690002A5D5C503.
  - The second parameter is the characteristics property, and the third parameter is the size of the data value of the characteristics.
- The second parameter in each command appears to represent a specific action or operation to be performed:
  - 02 is used for reading
  - 08 is used for writing
  - 18 is used for combined write and notify operations
Reboot the module using the R,1 command to ensure the new GATT details get stored in PDS.
To verify the GATT service is configured correctly:
1. Type the command mode sequence $$$ to enter the Command mode.
2. Issue the LS command to list the services.
  Figure 7-24. LS Command