nityc-d-robo/Nx_UDP_Echo_Client

Nx_UDP_Echo_Client Application Description

This application provides an example of Azure RTOS NetX/NetXDuo stack usage.

It shows how to develop a NetX udp client to communicate with a remote sever using the NetX UDP socket API.

The main entry function tx_application_define() is called by ThreadX during kernel start, at this stage, all NetX resources are created.

A NX_PACKET_POOLis allocated
A NX_IP instance using that pool is initialized
The ARP, ICMP and UDP protocols are enabled for the NX_IP instance
A DHCP client is created.

The application then creates 2 threads with the same priorities:

NxAppThread (priority 10, PreemtionThreashold 10) : created with the TX_AUTO_START flag to start automatically.
AppUDPThread (priority 10, PreemtionThreashold 10) : created with the TX_DONT_START flag to be started later.

The NxAppThread starts and perform the following actions:

Starts the DHCP client
Waits for the IP address resolution
Resumes the AppUDPThread

The AppUDPThread, once started:

Creates a UDP client socket
Connects to the remote UDP server on the predefined port
On connection success, the UDP client sends a MAX_PACKET_COUNT messages to the server.
At each message sent, the UDP client reads the sever response and prints it on the Hyperterminal and the green led is toggled.

Expected success behavior

The board IP address is printed on the HyperTerminal
The response messages sent by the server are printed on the HyerTerminal
if the echotool utility is used the message sent by the client are displayed on the PC console.
a summary message similar to the following is printed on the HyperTerminal and the green LED is toggling.

 SUCCESS : 10 / 10 packets sent

Error behaviors

The Red LED is toggling to indicate any error that has occurred.
In case the message exchange is not completed the HyperTerminal is not printing the received messages.

Assumptions if any

The Application is using the DHCP to acquire IP address, thus a DHCP server should be reachable by the board in the LAN used to test the application.
The application is configuring the Ethernet IP with a static predefined MAC Address, make sure to change it in case multiple boards are connected on the same LAN to avoid any potential network traffic issues.
The MAC Address is defined in the main.c

void MX_ETH_Init(void)
{

  /* USER CODE BEGIN ETH_Init 0 */

  /* USER CODE END ETH_Init 0 */

  /* USER CODE BEGIN ETH_Init 1 */

  /* USER CODE END ETH_Init 1 */
  heth.Instance = ETH;
  MACAddr[0] = 0x00;
  MACAddr[1] = 0x80;
  MACAddr[2] = 0xE1;
  MACAddr[3] = 0x00;
  MACAddr[4] = 0x00;
  MACAddr[5] = 0x00;

Known limitations

None

ThreadX usage hints

ThreadX uses the Systick as time base, thus it is mandatory that the HAL uses a separate time base through the TIM IPs.
ThreadX is configured with 100 ticks/sec by default, this should be taken into account when using delays or timeouts at application. It is always possible to reconfigure it in the "tx_user.h", the "TX_TIMER_TICKS_PER_SECOND" define,but this should be reflected in "tx_initialize_low_level.S" file too.
ThreadX is disabling all interrupts during kernel start-up to avoid any unexpected behavior, therefore all system related calls (HAL, BSP) should be done either at the beginning of the application or inside the thread entry functions.
ThreadX offers the "tx_application_define()" function, that is automatically called by the tx_kernel_enter() API. It is highly recommended to use it to create all applications ThreadX related resources (threads, semaphores, memory pools...) but it should not in any way contain a system API call (HAL or BSP).
Using dynamic memory allocation requires to apply some changes to the linker file. ThreadX needs to pass a pointer to the first free memory location in RAM to the tx_application_define() function, using the "first_unused_memory" argument. This require changes in the linker files to expose this memory location.
- For EWARM add the following section into the .icf file:
```
place in RAM_region    { last section FREE_MEM };
```
- For MDK-ARM:

  either define the RW_IRAM1 region in the ".sct" file
  or modify the line below in "tx_low_level_initilize.S to match the memory region being used
      LDR r1, =|Image$$RW_IRAM1$$ZI$$Limit|

+ For STM32CubeIDE add the following section into the .ld file:

  ._threadx_heap :
    {
       . = ALIGN(8);
       __RAM_segment_used_end__ = .;
       . = . + 64K;
       . = ALIGN(8);
     } >RAM_D1 AT> RAM_D1

   The simplest way to provide memory for ThreadX is to define a new section, see ._threadx_heap above.
   In the example above the ThreadX heap size is set to 64KBytes.
   The ._threadx_heap must be located between the .bss and the ._user_heap_stack sections in the linker script.  
   Caution: Make sure that ThreadX does not need more than the provided heap memory (64KBytes in this example).  
   Read more in STM32CubeIDE User Guide, chapter: "Linker script".

+ The "tx_initialize_low_level.S" should be also modified to enable the "USE_DYNAMIC_MEMORY_ALLOCATION" flag.

NetX Duo usage hints

Depending on the application scenario, the total TX and RX descriptors may need to be increased by updating respectively the "ETH_TX_DESC_CNT" and "ETH_RX_DESC_CNT" in the "stm32h5xx_hal_conf.h", to guarantee the application correct behaviour, but this will cost extra memory to allocate.

Keywords

RTOS, Network, ThreadX, NetXDuo, UDP, UART

Hardware and Software environment

This application runs on STM32H563xx devices.
This application has been tested with STMicroelectronics NUCLEO-H563ZI boards Revision: MB1404-H563ZI-A01. and can be easily tailored to any other supported device and development board.
This application uses USART3 to display logs, the hyperterminal configuration is as follows:
- BaudRate = 115200 baud
- Word Length = 8 Bits
- Stop Bit = 1
- Parity = None
- Flow control = None

How to use it ?

In order to make the program work, you must do the following :

Open your preferred toolchain
Edit the file NetXDuo/App/app_netxduo.h and correctly define the UDP_SERVER_ADDRESS and UDP_SERVER_PORT to connect on.

run the echotool utility on a windows console as following:

c:\> .\echotool.exe /p udp /s <UDP_SERVER_PORT> 

example : c:\> .\echotool.exe /p udp /s 6000

Rebuild all files and load your image into target memory
Run the application

nityc-d-robo / Nx_UDP_Echo_Client