New example files

1 files changed, 175 insertions, 0 deletions

diff --git a/boards/ek-lm4f120xl/freertos_demo/switch_task.c b/boards/ek-lm4f120xl/freertos_demo/switch_task.c
new file mode 100644
index 0000000..3665af4
--- /dev/null
+++ b/boards/ek-lm4f120xl/freertos_demo/switch_task.c
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+//*****************************************************************************

+//

+// switch_task.c - A simple switch task to process the buttons.

+//

+// Copyright (c) 2012 Texas Instruments Incorporated.  All rights reserved.

+// Software License Agreement

+// 

+// Texas Instruments (TI) is supplying this software for use solely and

+// exclusively on TI's microcontroller products. The software is owned by

+// TI and/or its suppliers, and is protected under applicable copyright

+// laws. You may not combine this software with "viral" open-source

+// software in order to form a larger program.

+// 

+// THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.

+// NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT

+// NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

+// A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY

+// CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL

+// DAMAGES, FOR ANY REASON WHATSOEVER.

+// 

+// This is part of revision 9453 of the EK-LM4F120XL Firmware Package.

+//

+//*****************************************************************************

+

+#include "inc/hw_memmap.h"

+#include "inc/hw_types.h"

+#include "inc/hw_gpio.h"

+#include "driverlib/sysctl.h"

+#include "driverlib/gpio.h"

+#include "driverlib/rom.h"

+#include "drivers/buttons.h"

+#include "utils/uartstdio.h"

+#include "switch_task.h"

+#include "led_task.h"

+#include "priorities.h"

+#include "FreeRTOS.h"

+#include "task.h"

+#include "queue.h"

+#include "semphr.h"

+

+//*****************************************************************************

+//

+// The stack size for the display task.

+//

+//*****************************************************************************

+#define SWITCHTASKSTACKSIZE        128         // Stack size in words

+

+extern xQueueHandle g_pLEDQueue;

+extern xSemaphoreHandle g_pUARTSemaphore;

+

+//*****************************************************************************

+//

+// This task reads the buttons' state and passes this information to LEDTask.

+//

+//*****************************************************************************

+static void

+SwitchTask(void *pvParameters)

+{

+    portTickType ulLastTime;

+    unsigned long ulSwitchDelay = 25;

+    unsigned char ucCurButtonState, ucPrevButtonState;

+    unsigned char ucMessage;

+

+    ucCurButtonState = ucPrevButtonState = 0;

+

+    //

+    // Get the current tick count.

+    //

+    ulLastTime = xTaskGetTickCount();

+

+    //

+    // Loop forever.

+    //

+    while(1)

+    {

+        //

+        // Poll the debounced state of the buttons.

+        //

+        ucCurButtonState = ButtonsPoll(0, 0);

+

+        //

+        // Check if previous debounced state is equal to the current state.

+        //

+        if(ucCurButtonState != ucPrevButtonState)

+        {

+            ucPrevButtonState = ucCurButtonState;

+

+            //

+            // Check to make sure the change in state is due to button press

+            // and not due to button release.

+            //

+            if((ucCurButtonState & ALL_BUTTONS) != 0)

+            {

+                if((ucCurButtonState & ALL_BUTTONS) == LEFT_BUTTON)

+                {

+                    ucMessage = LEFT_BUTTON;

+

+                    //

+                    // Guard UART from concurrent access.

+                    //

+                    xSemaphoreTake(g_pUARTSemaphore, portMAX_DELAY);

+                    UARTprintf("Left Button is pressed.\n");

+                    xSemaphoreGive(g_pUARTSemaphore);

+                }

+                else if((ucCurButtonState & ALL_BUTTONS) == RIGHT_BUTTON)

+                {

+                    ucMessage = RIGHT_BUTTON;

+

+                    //

+                    // Guard UART from concurrent access.

+                    //

+                    xSemaphoreTake(g_pUARTSemaphore, portMAX_DELAY);

+                    UARTprintf("Right Button is pressed.\n");

+                    xSemaphoreGive(g_pUARTSemaphore);

+                }

+

+                //

+                // Pass the value of the button pressed to LEDTask.

+                //

+                if(xQueueSend(g_pLEDQueue, &ucMessage, portMAX_DELAY) !=

+                   pdPASS)

+                {

+                    //

+                    // Error. The queue should never be full. If so print the

+                    // error message on UART and wait for ever.

+                    //

+                    UARTprintf("\nQueue full. This should never happen.\n");

+                    while(1)

+                    {

+                    }

+                }

+            }

+        }

+

+        //

+        // Wait for the required amount of time to check back.

+        //

+        vTaskDelayUntil(&ulLastTime, ulSwitchDelay / portTICK_RATE_MS);

+    }

+}

+

+//*****************************************************************************

+//

+// Initializes the switch task.

+//

+//*****************************************************************************

+unsigned long

+SwitchTaskInit(void)

+{

+    //

+    // Unlock the GPIO LOCK register for Right button to work.

+    //

+    HWREG(GPIO_PORTF_BASE + GPIO_O_LOCK) = GPIO_LOCK_KEY_DD;

+    HWREG(GPIO_PORTF_BASE + GPIO_O_CR) = 0xFF;

+

+    //

+    // Initialize the buttons

+    //

+    ButtonsInit();

+

+    //

+    // Create the switch task.

+    //

+    if(xTaskCreate(SwitchTask, (signed portCHAR *)"Switch",

+                   SWITCHTASKSTACKSIZE, NULL, tskIDLE_PRIORITY +

+                   PRIORITY_SWITCH_TASK, NULL) != pdTRUE)

+    {

+        return(1);

+    }

+

+    //

+    // Success.

+    //

+    return(0);

+}