SPMA072 March   2015 TM4C1294KCPDT , TM4C1294KCPDT , TM4C1294NCPDT , TM4C1294NCPDT , TM4C1294NCZAD , TM4C1294NCZAD , TM4C1299KCZAD , TM4C1299KCZAD , TM4C1299NCZAD , TM4C1299NCZAD , TM4C129EKCPDT , TM4C129EKCPDT , TM4C129ENCPDT , TM4C129ENCPDT , TM4C129ENCZAD , TM4C129ENCZAD , TM4C129XKCZAD , TM4C129XKCZAD , TM4C129XNCZAD , TM4C129XNCZAD

 

  1.   Serial to Ethernet Converter for TM4C129x Microcontrollers Using RTOS
    1.     Trademarks
    2. 1 Introduction
    3. 2 Software Description
    4. 3 Set Up and Program enet_s2e Application
      1. 3.1 Set Up enet_s2e Application
      2. 3.2 Software Modification for DK-TM4C129X
      3. 3.3 Program the enet_s2e Application
    5. 4 Demonstration
      1. 4.1 Set Up EK-TM4C1294XL Board and PC
      2. 4.2 Demonstration
    6. 5 Configuration Webserver
      1. 5.1 Access the Configuration Webserver
        1. 5.1.1 Using the Debug Port
        2. 5.1.2 Using the Finder Utility
      2. 5.2 Different Pages Hosted on the Configuration Webserver
        1. 5.2.1 S2E Status Page
        2. 5.2.2 S2E Port 0 and Port 1 Settings Page
        3. 5.2.3 S2E Miscellaneous Settings Page
    7. 6 Flow Control
    8. 7 Additional Hardware
      1. 7.1 Schematic of RS-232 Level Shifter
      2. 7.2 Connections
      3. 7.3 Bill of Materials (BOM)
    9. 8 References

1 Introduction

When a legacy product only contains a serial port for configuration or control, continuing to access the legacy product through the serial interface can become challenging over time. The following are the challenges of using a serial port:

  • The inability to add multiple such products to a shared network
  • The inability to access the legacy product from long distances
  • Modern PCs generally do not have RS-232 ports

Using Ethernet in place of the serial port provides the following benefits:

  • The legacy product can be more easily shared (instead of changing a cable connection, a new connection over the existing network is made)
  • Ability to access from longer distances. Cable length is no longer an issue
  • Ethernet is a more common interface available on today’s computing equipment

The software described in this application report (enet_s2e) allows an Ethernet-enabled TM4C129x microcontroller to be used as a serial-to-Ethernet converter. By connecting a serial-to-Ethernet converter to the serial port of a legacy product, it can be given the ability to operate on the Ethernet without requiring any changes to the existing hardware or software. This is especially useful when the legacy product cannot be modified (such as in the case of third-party products).

The software works out of the box on an EK-TM4C1294XL board. With minor modifications, the software can run on the DK-TM4C129X board. For details, see Section 3.2.

FreeRTOS has been used for scheduling the various tasks. Although an RTOS is not a requirement for this application, it has been used to make the application easily scalable.