OSA rtos - 2nd

After able to run a simple led blinking using OSA rtos, I plan to integrate one display function ( lcd 16x2) and two push button (event triggered).

So I have added one additional task which is taskDisplay(), the main purpose of task display is showing the some simple words and display simple message when push button is pressed.

The OSAcfg.h file remain the same
 //------------------------------------------------------------------------------
// SYSTEM
//------------------------------------------------------------------------------
// Number of tasks that can be active at one time, two tasks for led blinking, one task for display
#define OS_TASKS               3
// Not using any fancy OS function, so "no priority" setting is set
#define OS_DISABLE_PRIORITY    


For the HD44780 driver, it is remain the same as previous tutorial, I didnt include the OS function in the HD44780 source file.
The development board I used directly ground the RW pin of HD44780, so it is only writeable (unable to implement OS_Wait() function).
I have to use the delay function to wait for HD44780 finishes the operation. The longest wait period is 2ms for HD44780 whereas the OS_Timer() interval is set to be 10ms. If I use one tick delay, it will be 10ms. Still reasonable to implement but I am lazy. After wasting 2ms out of 10ms, I still have 8ms which is a lot of time to do other stuffs, not to mention just simple led blinking.


 //------------------------------------------------------------------------------
// TASK DISPLAY header file
//------------------------------------------------------------------------------
#ifndef TASK_DISPLAY_H
#define TASK_DISPLAY_H

#include "hd44780.h"
#include <osa.h>

#define mInitSW1()   {TRISBbits.TRISB0=1;} // initialise the port direction to input
#define mInitSW2()   {TRISBbits.TRISB1=1;} // initialise the port direction to input

#define mSW_1 PORTBbits.RB0 // switch one
#define mSW_2 PORTBbits.RB1 // switch two

void taskDisplay(void);

#endif /* TASK_DISPLAY_H */

 //------------------------------------------------------------------------------
// TASK DISPLAY source file
//------------------------------------------------------------------------------
void taskDisplay(void)
{
mInitSW1();
mInitSW2();

        // initialize the LCD module is time consuming but it doesn't interfere with OS                                      // operation as OS only run the function above the forever loop on first time.                                          // After that, at each interval, it run the function inside forever loop.
        HD44780_Init();

        HD44780_GoToPoint(1,1);
        HD44780_WriteROMString("  - RTOS OSA -  ");
HD44780_GoToPoint(2,1);
        HD44780_WriteROMString("  -Simple Demo- ");

       for (;;) {
  // wait for switch to be pressed, bad implementation as I do not consider                                               // the switch debounce or noise interference.
        OS_Wait(mSW_1==0);

HD44780_GoToPoint(2,1);


         // String written when switch one is pressed, I make it to be 16 characters so                                          // that I dont have to clear any character left at display.
        HD44780_WriteROMString("Button 1 Pressed");  

  OS_Wait(mSW_2==0);
HD44780_GoToPoint(2,1);

         // String written when switch 2 is pressed.
        HD44780_WriteROMString("Button 2 Pressed");  
    }
}



At the main file, create the task mentioned.
 //------------------------------------------------------------------------------
// CREATE TASK
//------------------------------------------------------------------------------
// Priority zero, all task has equal priority
    OS_Task_Create(0, taskLED1);
    OS_Task_Create(0, taskLED2);
    OS_Task_Create(0, taskDisplay);

Here is the output display,

After initialisation,

After switch one is pressed,

The project file is downloaded at link.