tcpecho

Example Summary

This application demonstrates how to use TCP.

Peripherals & Pin Assignments

• EMAC Connection to network

BoosterPacks, Board Resources & Jumper Settings

For board specific jumper settings, resources and BoosterPack modifications, refer to the Board.html file.

If you’re using an IDE such as Code Composer Studio (CCS) or IAR, please refer to Board.html in your project directory for resources used and board-specific jumper settings.

The Board.html can also be found in your SDK installation:

    <SDK_INSTALL_DIR>/source/ti/boards/<BOARD>

Python 3.X is required for this example. To install python download the latest version at https://www.python.org/downloads/release

Example Usage

• Example output is generated through use of Display driver APIs. Refer to the Display driver documentation found in the SimpleLink MCU SDK User’s Guide.

• Open a serial session (e.g. PuTTY, etc.) to the appropriate COM port.
  • The COM port can be determined via Device Manager in Windows or via ls /dev/tty* in Linux.

• The connection will have the following settings:

  Baud-rate:     115200
  Data bits:          8
  Stop bits:          1
  Parity:          None
  Flow Control:    None

• Connect an Ethernet cable to the Ethernet port on the device.

• The device must be connected to a network with a DHCP server to run this example successfully.

• The example starts the network stack. When the stack receives an IP address from the DHCP server, the IP address is written to the console.

• Run the tcpSendReceive python script that is shipped with your SDK.
  • The script is found in:

<SDK_INSTALL_DIR>/tools/examples/tcpSendReceive.py

Usage:

python tcpSendReceive.py <IP-addr> <port> <id> -l[length] -s[sleep in mS] -n[number of transmits per report]

  <IP-addr>     is the IP address of the device
  <port>        is the TCP port being listened to (1000)
  <id>          is a unique id for the executable. Printed out with a packet transmission report.
                It allows the user to run multiple instances of tcpSendReceive.


  Optional:
    -l[length]      size of the packet in bytes. Default is 1024 bytes.
    -s[sleep in mS] usleep time to between sends. Default is 0 mSecs.
    -n[number of transmits per report] the number of transmits to occur before being reported onto the console. Default is 100 transmits.

Example: python tcpSendReceive.py 192.168.1.100 1000 1 -s100

• Messages such as the following will begin to appear on the terminal window when a TCP packet has been echoed back:

      Starting test with a 100 mSec delay between transmits and reporting every 100 transmit(s)
      [id 1] count = 100, time = 10
      [id 1] count = 200, time = 20
      [id 1] count = 300, time = 30

Application Design Details

• This application uses two types of tasks:

1. tcpHandler - Creates a socket and accepts incoming connections. When a connection is established a tcpWorker task is dynamically created to send or receive data.
2. tcpWorker - Echoes TCP packets back to the client.

tcpHandler performs the following actions:

• Create a socket and bind it to a port (1000 for this example).
• Wait for incoming requests.
• Once a request is received, a new tcpWorker task is dynamically created to manage the communication (echo TCP packets).
• Waiting for new requests.

tcpWorker performs the following actions:

• Allocate memory to serve as a TCP packet buffer.
• Receive data from socket client.
• Echo the TCP packet back to the client.

• When client closes the socket, close server socket, free TCP buffer memory and exit the task.

• TI-RTOS:

  • When building in Code Composer Studio, the kernel configuration project will be imported along with the example. The kernel configuration project is referenced by the example, so it will be built first. The “release” kernel configuration is the default project used. It has many debug features disabled. These feature include assert checking, logging and runtime stack checks. For a detailed difference between the “release” and “debug” kernel configurations and how to switch between them, please refer to the SimpleLink MCU SDK User’s Guide. The “release” and “debug” kernel configuration projects can be found under <SDK_INSTALL_DIR>/kernel/tirtos/builds/<BOARD>/(release|debug)/(ccs|gcc).

• FreeRTOS:

  • Please view the FreeRTOSConfig.h header file for example configuration information.