How to integrate RTOS system to EmWi besides FreeRTOS?

Question

I have a working RTOS application on stm32fx device, and now I'd like to add UI created by EmWi.

I'm not sure which one is better ?

1. Add RTOS to IAR project that generated from EmWi

2. Include EmWi generated code into my exist IAR project

I had tried the first one. Modified from the FreeRTOS version generted by EmWi, and I replaced all of codes according to the EW_USE_FREE_RTOS define

But the screen didn't show correctly, it looks much bigger and repeatly, here is an picture for PaperCutter example:

Did anyone have experience to integrate other RTOS besides FreeRTOS? Any suggestions will be appreciated, Thanks!

Answer 1

Hi,

the doubled content on the screen is not related to the operating system. I assume that the display initialization / display timing is not correctly.

Did you use the same system clock settings and the same display settings (ew_bsp_display.c) as in case of FreeRTOS?

What kind of display are you using and how is it connected? What type of STM32Fx are you using?

Best regards,

Manfred.

Comments

I am using STM32F469 and on board screen (MIPI display serial interface).

I didn't change system clock settings and only modified the semaphore mechanism(in ew_bsp_display.c, ew_bsp_graphics.c and ew_bsp_event.c) to adapt my RTOS.

And one more thing, I do the same following code as in case of FreeRTOS that I don't really know why need to change priority.

#if USE_RTOS == 1
void HAL_DSI_MspInit(DSI_HandleTypeDef* hdsi)
{
  HAL_NVIC_SetPriority(DSI_IRQn, 8, 0);
}
#endif

 

---

Maybe you can try the following:

1.) Use a more simple application, e.g. HelloWorld

2.) Set the flag EW_USE_DOUBLE_BUFFER=0 within your makefile/toolchain. Then the synchronization / semaphore is more simple.

3.) Connect a serial terminal - maybe we get some useful message....

---

Thanks, I'll try it later !

BTW, did you think the method that I replaced all of codes in EW_USE_FREE_RTOS define is a corret way to integrate other RTOS with EmWi?

---

Yes in principal this should be a good approach.

Let us know the results of the above steps.

The interesting part: Is the destroyed display content just what you see while the application hangs - or is the application still running?

Btw: How many stack do you reserve for the UI application?

---

My result is almost the same as Toxic's. 

Here are messages from serial:

Create UI thread...                          [OK]
Initialize Display...                        [OK]
Initialize Touch Driver...                   [OK]
Initialize Memory Manager...                 [OK]
MemoryPool at address 0xC00BB800 size 0x00744800
Initialize Graphics Engine...                [OK]
Create Embedded Wizard Root Object...        [OK]
Create Embedded Wizard Viewport...           [OK]

And the stack size is config as 128 bytes, but nothing different when I changed the size to 512 bytes.

For the UI, it's still running and touch event works as normal situation. (the coordinate is right!)

---

In any case, the stack size is too small. Please reserve a stack of 4...8kBytes. But I assume this is not the root cause for the described problem.

Can you check the interrupt configuration for LTDC and DSI - especially if the HAL_DSI_TearingEffectCallback() and HAL_DSI_EndOfRefreshCallback() are called? I think these are not active / the callbacks are never called.

---

OK, I changed the stack size and I put EwPrint() function inside HAL_DSI_TearingEffectCallback() and HAL_DSI_EndOfRefreshCallback().

I can see both callback was called after boot and each time screen touched!

BTW, I tested if only change EW_USE_FREE_RTOS region in ew_bsp_event.c and leave other file (graphic, display) using non-OS function, It's works fine!

---

Can you try the same steps as Toxic: 

I configuered the ew_bsp_display, ew_bsp_ event and ew_bsp_graphics like I have no OS.

---

I just edited the previous commit =>  I tested if only change EW_USE_FREE_RTOS region in ew_bsp_event.c and leave other file (graphic, display) using non-OS function, It's works fine!

In this case, EmWiMainLoop is running in my OS thread and I also put my OS SysTick handler in stm32f4xx_it.c file. Also the picture will follow my touch as well.

 

 

Answer 2

Hi,

I have the same problem. I use the STM32F769I-Eval and Keil RTX. I started with the template of EW and integrated my code. I changed the freeRTOS to RTX.

After starting, the GUI is displayed correct. If I touch the display, I can see the absolute same problem like you.

If I use the semaphore for ew_bsp_graphics too, its totally messed up. The text will not showing correctly. So it seems that is a problem with the semaphore, but I don't know to debug.

So I am very intresed how you can fix this and I hope it works for me too.

 

Best regards,

Alex

Comments

There is no need to use a semaphore - in principle you can work with the flag.

The idea of the current implementation is: When using a service of the operating system, it can use the CPU time for other tasks instead of waiting for the flag. That's all.

---

Thanks to HsinHan, I can see maybe a big problem for me. I can't put the systick_handler in the stm32f4xx_it.c because it is already defined in the cm4.lib from RTX. I can't override this function. Is there a way to work around this problem?

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Hi Toxic, I don't know how RTX system tick working, just refer to this page: http://www.keil.com/support/man/docs/rlarm/rlarm_ar_alt_ticktim.htm

To configure an alternate peripheral timer as system tick timer, you have to:

1. implement the os_tick_init() and os_tick_irqack() functions in the RTX_Config.c configuration file.
2. replace the alternate timer interrupt vector with the OS_Tick_Handler in the Interrupt Vector Table in startup file.

My idea is do not replace the interrupt vector in startup_stm32f4xx.s file. Then put OS_Tick_Handler into SysTick_Handler() function in the stm32f4xx_it.c

Maybe like this:

void SysTick_Handler(void)
{
  HAL_IncTick();
  EwBspSystemTickIncrement();

  #if USE_RTX == 1
    OS_Tick_Handler ();
  #endif
}

 

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I found a good way for me to solve that problem. 

I changed  the EwGetTicks() function. Now use directly des os_Time instead of the EmWiSystemTicks. os_Time is also increased every 1ms.

unsigned long EwGetTicks( void )
{
  /* It is assumed that the extern EmWiSystemTicks variable is incremented every
     millisecond by a timer driven interrupt service routine. */
  return HAL_GetTick();
}

But then I had the problem that my screen freezed after some touch events and the systems runs in a hardfault. I figuered out, that there is a problem with the RGB888. If I use RGB8888 or RGB565 every thing works perfect.

Thank you guys for your great help.

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Hi Toxic,

thanks for the feedback - just to understand the hardfault: What compiler are you using?