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CC256x Beginners Guide
CC256x Beginners Guide walks you step-by-step through the SPP demo which is one of many demo and sample applications available.
Contents
Demo Overview[edit]
This demo allows users to evaluate TI's CC256x Bluetooth device by using the PAN1323EMK and the MSP-EXP430F5438 board/ Tiva DK-TM4C129X. The SPP sample application code is provided to enable a rich out-of-box experience to the user.
The application allows the user to use a console to:
- Send Bluetooth commands
- Setup a Bluetooth Device to accept connections
- Connect to a remote Bluetooth device
- Communicate over Bluetooth
For information of the LE version of this profile, refer to the document SPP-LE profile.
It is recommended that the user visits the kit setup Getting Started Guide for MSP-430 or Getting Started Guide for Tiva C pages before trying the application described on this page.
Running the Bluetooth Code[edit]
Once the code is flashed, connect the board to a PC using a miniUSB to USB cable. Once connected, wait for the driver to install. It will show up as MXP-EXP430F5438 USB - Serial Port(COM x) under Ports(COM & LPT) or Tiva Virtual COM Port(COM x) under Ports(COM & LPT)in the Device manager. Attach a Terminal program like Tera Term to the serial port (COM x) for the board. The serial parameters to use are 115200 Baud, 8,N,1 and no flow control. Once connected, reset the device using Reset (S3 button for MXP-EXP430F5438) and you should see the stack getting initialized on the terminal.
Demo Application[edit]
This section provides a description of how to use the demo application to connect two configured board and communicate over Bluetooth. Bluetooth SPP is a simple Client-Server connection process. We will setup one of the boards as a server and the other board as a client. We will then initiate a connection from the client to the server. Once connected, we can transmit data between the two devices over Bluetooth.
Server setup on the demo application[edit]
- a) We will setup the first board as a server. Perform the steps mentioned earlier in "Running the Bluetooth Code" section to initialize the application. Once initialized, note the Bluetooth address of the server. We will later use this to initiate a connection from the client.
- b) On the "Choose mode>" prompt, enter "Server".
- c) You will see a list of all possible commands at this time for a server. You can see this list at any time by entering "Help" at the Server> prompt.
- d) Now we are ready to open a server. To open a server, at the "Server>" prompt, enter "Open 1". You can replace 1 with any number between 1 and 30, as long as there is no server open on that port. Once you see "Server opened: 1", you have a SPP server open on port 1.
Client setup and device discovery on the demo application[edit]
- e) We will setup the second board as a client. Perform the steps mentioned earlier in "Running the Bluetooth Code" section to initialize the application. On the "Choose mode>" prompt, enter "Client".
- f) You will see a list of all possible commands at this time for a Client. You can see this list at any time by entering "Help" at the Client> prompt.
- g) At the "Client>" prompt, enter "Inquiry". This will initiate the Inquiry process. Once it is complete, you will get a list of all discovered devices.
- h) You can access this list any time by choosing "DisplayInquiryList" at the Client prompt.
Initiating connection from the client[edit]
- i)Note the index number of the first board that was configured as a server. [If the list is not on the screen, issue "DisplayInquiryList" command on the client to display the list of discovered devices again. ]
- j) Issue a "Open <index number> <server port number>" command at the command prompt.
- k) Wait for SPP Open confirmation.
- l) When a client successfully connects to a server, the server will see the open indication.
Data Transfer between Client and Server[edit]
- m) Now we have a SPP connection established and both devices are ready to transmit data to each other.
- n) On Client or Server you can send some data to the remote side by issuing a "Write" command. This command sends a hardcoded test string to the other side.
- o) The remote side will receive a data indication
- p) The user can read the data by issuing a "Read" command.
- q) The connection can be closed on either side by issuing the close command. In the example the client closes the connection and the server receives a close indication.
Note:
In the shipped SPP application that is a part of the SPP/SPPLE application , using the write command sends 76 bytes to the other device. It is not possible for the sender to send all 76 bytes at once because of the limitations on buffers that are smaller to reduce RAM usage. So the code sends 31 bytes and waits until the other side is ready to receive more. The other side will not be ready until it reads the sent data by calling a "read" operation. So the idea is to call Read whenever the receiver receives an SPP Data Indication and all data that was sent will be read.
An example communication
Client Side:
SPP+LE>write
Wrote: 76.
SPP+LE>
Transmit Buffer Empty Indication, ID: 0x0001
Server Side (Receiving Data):
SPP+LE>
SPP Data Indication, ID: 0x0001, Length: 0x0026.
SPP+LE>read
Read: 31.
Message: ~!@#$%^&*()_+`1234567890-=:;"'<
Read: 7.
Message: >?,./@A
Read: 0.
SPP+LE>
SPP Data Indication, ID: 0x0001, Length: 0x0026.
SPP+LE>read
Read: 31.
Message: BCDEFGHIJKLMNOPQRSTUVWXYZ[\]`ab
Read: 7.
Message: cdefghi
Read: 0.
So we have:
31+31+7+7=76.