begriffs open source - cmsis-freertos/blob

1 /*

4

5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

6

7 This file is part of the FreeRTOS distribution.

8

9 FreeRTOS is free software; you can redistribute it and/or modify it under

10 the terms of the GNU General Public License (version 2) as published by the

11 Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.

12

13 ***************************************************************************

14 >>! NOTE: The modification to the GPL is included to allow you to !<<

15 >>! distribute a combined work that includes FreeRTOS without being !<<

16 >>! obliged to provide the source code for proprietary components !<<

17 >>! outside of the FreeRTOS kernel. !<<

18 ***************************************************************************

19

20 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY

21 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

22 FOR A PARTICULAR PURPOSE. Full license text is available on the following

23 link: http://www.freertos.org/a00114.html

24

25 ***************************************************************************

26 * *

27 * FreeRTOS provides completely free yet professionally developed, *

28 * robust, strictly quality controlled, supported, and cross *

29 * platform software that is more than just the market leader, it *

30 * is the industry's de facto standard. *

31 * *

32 * Help yourself get started quickly while simultaneously helping *

33 * to support the FreeRTOS project by purchasing a FreeRTOS *

34 * tutorial book, reference manual, or both: *

35 * http://www.FreeRTOS.org/Documentation *

36 * *

37 ***************************************************************************

38

39 http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading

40 the FAQ page "My application does not run, what could be wrong?". Have you

41 defined configASSERT()?

42

43 http://www.FreeRTOS.org/support - In return for receiving this top quality

44 embedded software for free we request you assist our global community by

45 participating in the support forum.

46

47 http://www.FreeRTOS.org/training - Investing in training allows your team to

48 be as productive as possible as early as possible. Now you can receive

49 FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers

50 Ltd, and the world's leading authority on the world's leading RTOS.

51

52 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,

53 including FreeRTOS+Trace - an indispensable productivity tool, a DOS

54 compatible FAT file system, and our tiny thread aware UDP/IP stack.

55

56 http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.

57 Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.

58

59 http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High

60 Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS

61 licenses offer ticketed support, indemnification and commercial middleware.

62

63 http://www.SafeRTOS.com - High Integrity Systems also provide a safety

64 engineered and independently SIL3 certified version for use in safety and

65 mission critical applications that require provable dependability.

66

67 1 tab == 4 spaces!

68 */

69

70 /* peripheral library include */

71 #include <plib.h>

72

73 /* Scheduler includes. */

74 #include "FreeRTOS.h"

75 #include "task.h"

76 #include "queue.h"

77

78 /* Demo includes. */

79 #include "lcd.h"

80

81 /*

82 * The LCD is written to by more than one task so is controlled by this

83 * 'gatekeeper' task. This is the only task that is actually permitted to

84 * access the LCD directly. Other tasks wanting to display a message send

85 * the message to the gatekeeper.

86 */

87 static void vLCDTask( void *pvParameters );

88

89 /*

90 * Setup the peripherals required to communicate with the LCD.

91 */

92 static void prvSetupLCD( void );

93

94 /*

95 * Move to the first (0) or second (1) row of the LCD.

96 */

97 static void prvLCDGotoRow( unsigned short usRow );

98

99 /*

100 * Write a string of text to the LCD.

101 */

102 static void prvLCDPutString( char *pcString );

103

104 /*

105 * Clear the LCD.

106 */

107 static void prvLCDClear( void );

108

109 /*-----------------------------------------------------------*/

110

111 /* Brief delay to permit the LCD to catch up with commands. */

112 #define lcdVERY_SHORT_DELAY ( 1 )

113 #define lcdSHORT_DELAY ( 8 / portTICK_PERIOD_MS )

114 #define lcdLONG_DELAY ( 15 / portTICK_PERIOD_MS )

115

116 /* LCD specific definitions. */

117 #define LCD_CLEAR_DISPLAY_CMD 0x01

118 #define LCD_CURSOR_HOME_CMD 0x02

119 #define LCD_ENTRY_MODE_CMD 0x04

120 #define LCD_ENTRY_MODE_INCREASE 0x02

121 #define LCD_DISPLAY_CTRL_CMD 0x08

122 #define LCD_DISPLAY_CTRL_DISPLAY_ON 0x04

123 #define LCD_FUNCTION_SET_CMD 0x20

124 #define LCD_FUNCTION_SET_8_BITS 0x10

125 #define LCD_FUNCTION_SET_2_LINES 0x08

126 #define LCD_FUNCTION_SET_LRG_FONT 0x04

127 #define LCD_NEW_LINE 0xC0

128 #define LCD_COMMAND_ADDRESS 0x00

129 #define LCD_DATA_ADDRESS 0x01

130

131 /* The length of the queue used to send messages to the LCD gatekeeper task. */

132 #define lcdQUEUE_SIZE 3

133

134 /*-----------------------------------------------------------*/

135

136 /* The queue used to send messages to the LCD task. */

137 QueueHandle_t xLCDQueue;

138

139 /* LCD access functions. */

140 static void prvLCDCommand( char cCommand );

141 static void prvLCDData( char cChar );

142

143 /*-----------------------------------------------------------*/

144

145 QueueHandle_t xStartLCDTask( void )

146 {

147 /* Create the queue used by the LCD task. Messages for display on the LCD

148 are received via this queue. */

149 xLCDQueue = xQueueCreate( lcdQUEUE_SIZE, sizeof( xLCDMessage ));

150

151 /* Start the task that will write to the LCD. The LCD hardware is

152 initialised from within the task itself so delays can be used. */

153 xTaskCreate( vLCDTask, "LCD", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL );

154

155 return xLCDQueue;

156 }

157 /*-----------------------------------------------------------*/

158

159 static void prvLCDGotoRow( unsigned short usRow )

160 {

161 if(usRow == 0)

162 {

163 prvLCDCommand( LCD_CURSOR_HOME_CMD );

164 }

165 else

166 {

167 prvLCDCommand( LCD_NEW_LINE );

168 }

169 }

170 /*-----------------------------------------------------------*/

171

172 static void prvLCDCommand( char cCommand )

173 {

174 PMPSetAddress( LCD_COMMAND_ADDRESS );

175 PMPMasterWrite( cCommand );

176 vTaskDelay( lcdSHORT_DELAY );

177 }

178 /*-----------------------------------------------------------*/

179

180 static void prvLCDData( char cChar )

181 {

182 PMPSetAddress( LCD_DATA_ADDRESS );

183 PMPMasterWrite( cChar );

184 vTaskDelay( lcdVERY_SHORT_DELAY );

185 }

186 /*-----------------------------------------------------------*/

187

188 static void prvLCDPutString( char *pcString )

189 {

190 /* Write out each character with appropriate delay between each. */

191 while(*pcString)

192 {

193 prvLCDData(*pcString);

194 pcString++;

195 vTaskDelay(lcdSHORT_DELAY);

196 }

197 }

198 /*-----------------------------------------------------------*/

199

200 static void prvLCDClear(void)

201 {

202 prvLCDCommand(LCD_CLEAR_DISPLAY_CMD);

203 }

204 /*-----------------------------------------------------------*/

205

206 static void prvSetupLCD(void)

207 {

208 /* Wait for proper power up. */

209 vTaskDelay( lcdLONG_DELAY );

210

211 /* Open the PMP port */

212 mPMPOpen((PMP_ON | PMP_READ_WRITE_EN | PMP_CS2_CS1_EN |

213 PMP_LATCH_POL_HI | PMP_CS2_POL_HI | PMP_CS1_POL_HI |

214 PMP_WRITE_POL_HI | PMP_READ_POL_HI),

215 (PMP_MODE_MASTER1 | PMP_WAIT_BEG_4 | PMP_WAIT_MID_15 |

216 PMP_WAIT_END_4),

217 PMP_PEN_0, 0);

218

219 /* Wait for the LCD to power up correctly. */

220 vTaskDelay( lcdLONG_DELAY );

221 vTaskDelay( lcdLONG_DELAY );

222 vTaskDelay( lcdLONG_DELAY );

223

224 /* Set up the LCD function. */

225 prvLCDCommand( LCD_FUNCTION_SET_CMD | LCD_FUNCTION_SET_8_BITS | LCD_FUNCTION_SET_2_LINES | LCD_FUNCTION_SET_LRG_FONT );

226

227 /* Turn the display on. */

228 prvLCDCommand( LCD_DISPLAY_CTRL_CMD | LCD_DISPLAY_CTRL_DISPLAY_ON );

229

230 /* Clear the display. */

231 prvLCDCommand( LCD_CLEAR_DISPLAY_CMD );

232 vTaskDelay( lcdLONG_DELAY );

233

234 /* Increase the cursor. */

235 prvLCDCommand( LCD_ENTRY_MODE_CMD | LCD_ENTRY_MODE_INCREASE );

236 vTaskDelay( lcdLONG_DELAY );

237 vTaskDelay( lcdLONG_DELAY );

238 vTaskDelay( lcdLONG_DELAY );

239 }

240 /*-----------------------------------------------------------*/

241

242 static void vLCDTask(void *pvParameters)

243 {

244 xLCDMessage xMessage;

245 unsigned short usRow = 0;

246

247 /* Initialise the hardware. This uses delays so must not be called prior

248 to the scheduler being started. */

249 prvSetupLCD();

250

251 /* Welcome message. */

252 prvLCDPutString( "www.FreeRTOS.org" );

253

254 for(;;)

255 {

256 /* Wait for a message to arrive that requires displaying. */

257 while( xQueueReceive( xLCDQueue, &xMessage, portMAX_DELAY ) != pdPASS );

258

259 /* Clear the current display value. */

260 prvLCDClear();

261

262 /* Switch rows each time so we can see that the display is still being

263 updated. */

264 prvLCDGotoRow( usRow & 0x01 );

265 usRow++;

266 prvLCDPutString( xMessage.pcMessage );

267

268 /* Delay the requested amount of time to ensure the text just written

269 to the LCD is not overwritten. */

270 vTaskDelay( xMessage.xMinDisplayTime );

271 }

272 }