2 FreeRTOS V7.5.1 - Copyright (C) 2013 Real Time Engineers Ltd.
\r
4 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
\r
6 ***************************************************************************
\r
8 * FreeRTOS provides completely free yet professionally developed, *
\r
9 * robust, strictly quality controlled, supported, and cross *
\r
10 * platform software that has become a de facto standard. *
\r
12 * Help yourself get started quickly and support the FreeRTOS *
\r
13 * project by purchasing a FreeRTOS tutorial book, reference *
\r
14 * manual, or both from: http://www.FreeRTOS.org/Documentation *
\r
18 ***************************************************************************
\r
20 This file is part of the FreeRTOS distribution.
\r
22 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
23 the terms of the GNU General Public License (version 2) as published by the
\r
24 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
\r
26 >>! NOTE: The modification to the GPL is included to allow you to distribute
\r
27 >>! a combined work that includes FreeRTOS without being obliged to provide
\r
28 >>! the source code for proprietary components outside of the FreeRTOS
\r
31 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
\r
32 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
\r
33 FOR A PARTICULAR PURPOSE. Full license text is available from the following
\r
34 link: http://www.freertos.org/a00114.html
\r
38 ***************************************************************************
\r
40 * Having a problem? Start by reading the FAQ "My application does *
\r
41 * not run, what could be wrong?" *
\r
43 * http://www.FreeRTOS.org/FAQHelp.html *
\r
45 ***************************************************************************
\r
47 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
\r
48 license and Real Time Engineers Ltd. contact details.
\r
50 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
51 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
\r
52 compatible FAT file system, and our tiny thread aware UDP/IP stack.
\r
54 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
\r
55 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
\r
56 licenses offer ticketed support, indemnification and middleware.
\r
58 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
\r
59 engineered and independently SIL3 certified version for use in safety and
\r
60 mission critical applications that require provable dependability.
\r
67 * This project contains an application demonstrating the use of the
\r
68 * FreeRTOS.org mini real time scheduler on the Luminary Micro LM3S811 Eval
\r
69 * board. See http://www.FreeRTOS.org for more information.
\r
71 * main() simply sets up the hardware, creates all the demo application tasks,
\r
72 * then starts the scheduler. http://www.freertos.org/a00102.html provides
\r
73 * more information on the standard demo tasks.
\r
75 * In addition to a subset of the standard demo application tasks, main.c also
\r
76 * defines the following tasks:
\r
78 * + A 'Print' task. The print task is the only task permitted to access the
\r
79 * LCD - thus ensuring mutual exclusion and consistent access to the resource.
\r
80 * Other tasks do not access the LCD directly, but instead send the text they
\r
81 * wish to display to the print task. The print task spends most of its time
\r
82 * blocked - only waking when a message is queued for display.
\r
84 * + A 'Button handler' task. The eval board contains a user push button that
\r
85 * is configured to generate interrupts. The interrupt handler uses a
\r
86 * semaphore to wake the button handler task - demonstrating how the priority
\r
87 * mechanism can be used to defer interrupt processing to the task level. The
\r
88 * button handler task sends a message both to the LCD (via the print task) and
\r
89 * the UART where it can be viewed using a dumb terminal (via the UART to USB
\r
90 * converter on the eval board). NOTES: The dumb terminal must be closed in
\r
91 * order to reflash the microcontroller. A very basic interrupt driven UART
\r
92 * driver is used that does not use the FIFO. 19200 baud is used.
\r
94 * + A 'check' task. The check task only executes every five seconds but has a
\r
95 * high priority so is guaranteed to get processor time. Its function is to
\r
96 * check that all the other tasks are still operational and that no errors have
\r
97 * been detected at any time. If no errors have every been detected 'PASS' is
\r
98 * written to the display (via the print task) - if an error has ever been
\r
99 * detected the message is changed to 'FAIL'. The position of the message is
\r
100 * changed for each write.
\r
105 /* Environment includes. */
\r
106 #include "DriverLib.h"
\r
108 /* Scheduler includes. */
\r
109 #include "FreeRTOS.h"
\r
112 #include "semphr.h"
\r
114 /* Demo app includes. */
\r
115 #include "integer.h"
\r
117 #include "semtest.h"
\r
118 #include "BlockQ.h"
\r
120 /* Delay between cycles of the 'check' task. */
\r
121 #define mainCHECK_DELAY ( ( portTickType ) 5000 / portTICK_RATE_MS )
\r
123 /* UART configuration - note this does not use the FIFO so is not very
\r
125 #define mainBAUD_RATE ( 19200 )
\r
126 #define mainFIFO_SET ( 0x10 )
\r
128 /* Demo task priorities. */
\r
129 #define mainQUEUE_POLL_PRIORITY ( tskIDLE_PRIORITY + 2 )
\r
130 #define mainCHECK_TASK_PRIORITY ( tskIDLE_PRIORITY + 3 )
\r
131 #define mainSEM_TEST_PRIORITY ( tskIDLE_PRIORITY + 1 )
\r
132 #define mainBLOCK_Q_PRIORITY ( tskIDLE_PRIORITY + 2 )
\r
134 /* Demo board specifics. */
\r
135 #define mainPUSH_BUTTON GPIO_PIN_4
\r
138 #define mainQUEUE_SIZE ( 3 )
\r
139 #define mainDEBOUNCE_DELAY ( ( portTickType ) 150 / portTICK_RATE_MS )
\r
140 #define mainNO_DELAY ( ( portTickType ) 0 )
\r
142 * Configure the processor and peripherals for this demo.
\r
144 static void prvSetupHardware( void );
\r
147 * The 'check' task, as described at the top of this file.
\r
149 static void vCheckTask( void *pvParameters );
\r
152 * The task that is woken by the ISR that processes GPIO interrupts originating
\r
153 * from the push button.
\r
155 static void vButtonHandlerTask( void *pvParameters );
\r
158 * The task that controls access to the LCD.
\r
160 static void vPrintTask( void *pvParameter );
\r
162 /* String that is transmitted on the UART. */
\r
163 static portCHAR *cMessage = "Task woken by button interrupt! --- ";
\r
164 static volatile portCHAR *pcNextChar;
\r
166 /* The semaphore used to wake the button handler task from within the GPIO
\r
167 interrupt handler. */
\r
168 xSemaphoreHandle xButtonSemaphore;
\r
170 /* The queue used to send strings to the print task for display on the LCD. */
\r
171 xQueueHandle xPrintQueue;
\r
173 /*-----------------------------------------------------------*/
\r
177 /* Configure the clocks, UART and GPIO. */
\r
178 prvSetupHardware();
\r
180 /* Create the semaphore used to wake the button handler task from the GPIO
\r
182 vSemaphoreCreateBinary( xButtonSemaphore );
\r
183 xSemaphoreTake( xButtonSemaphore, 0 );
\r
185 /* Create the queue used to pass message to vPrintTask. */
\r
186 xPrintQueue = xQueueCreate( mainQUEUE_SIZE, sizeof( portCHAR * ) );
\r
188 /* Start the standard demo tasks. */
\r
189 vStartIntegerMathTasks( tskIDLE_PRIORITY );
\r
190 vStartPolledQueueTasks( mainQUEUE_POLL_PRIORITY );
\r
191 vStartSemaphoreTasks( mainSEM_TEST_PRIORITY );
\r
192 vStartBlockingQueueTasks( mainBLOCK_Q_PRIORITY );
\r
194 /* Start the tasks defined within the file. */
\r
195 xTaskCreate( vCheckTask, "Check", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY, NULL );
\r
196 xTaskCreate( vButtonHandlerTask, "Status", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY + 1, NULL );
\r
197 xTaskCreate( vPrintTask, "Print", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY - 1, NULL );
\r
199 /* Start the scheduler. */
\r
200 vTaskStartScheduler();
\r
202 /* Will only get here if there was insufficient heap to start the
\r
207 /*-----------------------------------------------------------*/
\r
209 static void vCheckTask( void *pvParameters )
\r
211 portBASE_TYPE xErrorOccurred = pdFALSE;
\r
212 portTickType xLastExecutionTime;
\r
213 const portCHAR *pcPassMessage = "PASS";
\r
214 const portCHAR *pcFailMessage = "FAIL";
\r
216 /* Initialise xLastExecutionTime so the first call to vTaskDelayUntil()
\r
217 works correctly. */
\r
218 xLastExecutionTime = xTaskGetTickCount();
\r
222 /* Perform this check every mainCHECK_DELAY milliseconds. */
\r
223 vTaskDelayUntil( &xLastExecutionTime, mainCHECK_DELAY );
\r
225 /* Has an error been found in any task? */
\r
227 if( xAreIntegerMathsTaskStillRunning() != pdTRUE )
\r
229 xErrorOccurred = pdTRUE;
\r
232 if( xArePollingQueuesStillRunning() != pdTRUE )
\r
234 xErrorOccurred = pdTRUE;
\r
237 if( xAreSemaphoreTasksStillRunning() != pdTRUE )
\r
239 xErrorOccurred = pdTRUE;
\r
242 if( xAreBlockingQueuesStillRunning() != pdTRUE )
\r
244 xErrorOccurred = pdTRUE;
\r
247 /* Send either a pass or fail message. If an error is found it is
\r
248 never cleared again. We do not write directly to the LCD, but instead
\r
249 queue a message for display by the print task. */
\r
250 if( xErrorOccurred == pdTRUE )
\r
252 xQueueSend( xPrintQueue, &pcFailMessage, portMAX_DELAY );
\r
256 xQueueSend( xPrintQueue, &pcPassMessage, portMAX_DELAY );
\r
260 /*-----------------------------------------------------------*/
\r
262 static void prvSetupHardware( void )
\r
264 /* Setup the PLL. */
\r
265 SysCtlClockSet( SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_6MHZ );
\r
267 /* Setup the push button. */
\r
268 SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);
\r
269 GPIODirModeSet(GPIO_PORTC_BASE, mainPUSH_BUTTON, GPIO_DIR_MODE_IN);
\r
270 GPIOIntTypeSet( GPIO_PORTC_BASE, mainPUSH_BUTTON,GPIO_FALLING_EDGE );
\r
271 IntPrioritySet( INT_GPIOC, configKERNEL_INTERRUPT_PRIORITY );
\r
272 GPIOPinIntEnable( GPIO_PORTC_BASE, mainPUSH_BUTTON );
\r
273 IntEnable( INT_GPIOC );
\r
277 /* Enable the UART. */
\r
278 SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
\r
279 SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
\r
281 /* Set GPIO A0 and A1 as peripheral function. They are used to output the
\r
283 GPIODirModeSet( GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1, GPIO_DIR_MODE_HW );
\r
285 /* Configure the UART for 8-N-1 operation. */
\r
286 UARTConfigSetExpClk( UART0_BASE, SysCtlClockGet(), mainBAUD_RATE, UART_CONFIG_WLEN_8 | UART_CONFIG_PAR_NONE | UART_CONFIG_STOP_ONE );
\r
288 /* We don't want to use the fifo. This is for test purposes to generate
\r
289 as many interrupts as possible. */
\r
290 HWREG( UART0_BASE + UART_O_LCR_H ) &= ~mainFIFO_SET;
\r
292 /* Enable Tx interrupts. */
\r
293 HWREG( UART0_BASE + UART_O_IM ) |= UART_INT_TX;
\r
294 IntPrioritySet( INT_UART0, configKERNEL_INTERRUPT_PRIORITY );
\r
295 IntEnable( INT_UART0 );
\r
298 /* Initialise the LCD> */
\r
299 OSRAMInit( false );
\r
300 OSRAMStringDraw("www.FreeRTOS.org", 0, 0);
\r
301 OSRAMStringDraw("LM3S811 demo", 16, 1);
\r
303 /*-----------------------------------------------------------*/
\r
305 static void vButtonHandlerTask( void *pvParameters )
\r
307 const portCHAR *pcInterruptMessage = "Int";
\r
311 /* Wait for a GPIO interrupt to wake this task. */
\r
312 while( xSemaphoreTake( xButtonSemaphore, portMAX_DELAY ) != pdPASS );
\r
314 /* Start the Tx of the message on the UART. */
\r
315 UARTIntDisable( UART0_BASE, UART_INT_TX );
\r
317 pcNextChar = cMessage;
\r
319 /* Send the first character. */
\r
320 if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )
\r
322 HWREG( UART0_BASE + UART_O_DR ) = *pcNextChar;
\r
327 UARTIntEnable(UART0_BASE, UART_INT_TX);
\r
329 /* Queue a message for the print task to display on the LCD. */
\r
330 xQueueSend( xPrintQueue, &pcInterruptMessage, portMAX_DELAY );
\r
332 /* Make sure we don't process bounces. */
\r
333 vTaskDelay( mainDEBOUNCE_DELAY );
\r
334 xSemaphoreTake( xButtonSemaphore, mainNO_DELAY );
\r
338 /*-----------------------------------------------------------*/
\r
340 void vUART_ISR(void)
\r
342 unsigned portLONG ulStatus;
\r
344 /* What caused the interrupt. */
\r
345 ulStatus = UARTIntStatus( UART0_BASE, pdTRUE );
\r
347 /* Clear the interrupt. */
\r
348 UARTIntClear( UART0_BASE, ulStatus );
\r
350 /* Was a Tx interrupt pending? */
\r
351 if( ulStatus & UART_INT_TX )
\r
353 /* Send the next character in the string. We are not using the FIFO. */
\r
354 if( *pcNextChar != NULL )
\r
356 if( !( HWREG( UART0_BASE + UART_O_FR ) & UART_FR_TXFF ) )
\r
358 HWREG( UART0_BASE + UART_O_DR ) = *pcNextChar;
\r
364 /*-----------------------------------------------------------*/
\r
366 void vGPIO_ISR( void )
\r
368 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
\r
370 /* Clear the interrupt. */
\r
371 GPIOPinIntClear(GPIO_PORTC_BASE, mainPUSH_BUTTON);
\r
373 /* Wake the button handler task. */
\r
374 xSemaphoreGiveFromISR( xButtonSemaphore, &xHigherPriorityTaskWoken );
\r
375 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
\r
377 /*-----------------------------------------------------------*/
\r
379 static void vPrintTask( void *pvParameters )
\r
381 portCHAR *pcMessage;
\r
382 unsigned portBASE_TYPE uxLine = 0, uxRow = 0;
\r
386 /* Wait for a message to arrive. */
\r
387 xQueueReceive( xPrintQueue, &pcMessage, portMAX_DELAY );
\r
389 /* Write the message to the LCD. */
\r
393 OSRAMStringDraw( pcMessage, uxLine & 0x3f, uxRow & 0x01);
\r