Select one of the symbols to view example projects that use it.
 
Outline
Includes
#include "main.h"
Private includes
Private typedef
Private define
Private macro
Private variables
huart2
hdma_usart2_rx
aTextInfoStart
aRXBufferUser
aRXBufferA
aRXBufferB
uwNbReceivedChars
pBufferReadyForUser
pBufferReadyForReception
Private function prototypes
main()
SystemClock_Config()
MX_USART2_UART_Init()
MX_DMA_Init()
MX_GPIO_Init()
PrintInfo(UART_HandleTypeDef *, uint8_t *, uint16_t)
StartReception()
UserDataTreatment(UART_HandleTypeDef *, uint8_t *, uint16_t)
HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *, uint16_t)
Error_Handler()
Files
loading...
CodeScopeSTM32 Libraries and SamplesUART_ReceptionToIdle_CircularDMASrc/main.c
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
/* USER CODE BEGIN Header */ /** ****************************************************************************** * @file : main.c * @brief : Main program body ****************************************************************************** * @attention * * Copyright (c) 2020 STMicroelectronics. * All rights reserved. * * This software is licensed under terms that can be found in the LICENSE file * in the root directory of this software component. * If no LICENSE file comes with this software, it is provided AS-IS. * ****************************************************************************** *//* ... */ /* USER CODE END Header */ /* Includes ------------------------------------------------------------------*/ #include "main.h" Includes /* Private includes ----------------------------------------------------------*/ /* USER CODE BEGIN Includes */ /* USER CODE END Includes */ Private includes /* Private typedef -----------------------------------------------------------*/ /* USER CODE BEGIN PTD */ /* USER CODE END PTD */ Private typedef /* Private define ------------------------------------------------------------*/ /* USER CODE BEGIN PD */ /* USER CODE END PD */ Private define /* Private macro -------------------------------------------------------------*/ /* USER CODE BEGIN PM */ /* USER CODE END PM */ Private macro /* Private variables ---------------------------------------------------------*/ UART_HandleTypeDef huart2; DMA_HandleTypeDef hdma_usart2_rx; /* USER CODE BEGIN PV */ /** * @brief Text strings printed on PC Com port for user information *//* ... */ uint8_t aTextInfoStart[] = "\r\nUSART Example : Enter characters to fill reception buffers.\r\n"; uint8_t aRXBufferUser[RX_BUFFER_SIZE]; /** * @brief Data buffers used to manage received data in interrupt routine *//* ... */ uint8_t aRXBufferA[RX_BUFFER_SIZE]; uint8_t aRXBufferB[RX_BUFFER_SIZE]; __IO uint32_t uwNbReceivedChars; uint8_t *pBufferReadyForUser; uint8_t *pBufferReadyForReception; /* USER CODE END PV */ Private variables /* Private function prototypes -----------------------------------------------*/ void SystemClock_Config(void); static void MX_GPIO_Init(void); static void MX_DMA_Init(void); static void MX_USART2_UART_Init(void); /* USER CODE BEGIN PFP */ void PrintInfo(UART_HandleTypeDef *huart, uint8_t *String, uint16_t Size); void StartReception(void); void UserDataTreatment(UART_HandleTypeDef *huart, uint8_t* pData, uint16_t Size); /* USER CODE END PFP */ Private function prototypes /* Private user code ---------------------------------------------------------*/ /* USER CODE BEGIN 0 */ /* USER CODE END 0 */ /** * @brief The application entry point. * @retval int *//* ... */ int main(void) { /* USER CODE BEGIN 1 */ /* STM32F4xx HAL library initialization: - Configure the Flash prefetch - Systick timer is configured by default as source of time base, but user can eventually implement his proper time base source (a general purpose timer for example or other time source), keeping in mind that Time base duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and handled in milliseconds basis. - Set NVIC Group Priority to 4 - Low Level Initialization *//* ... */ /* USER CODE END 1 */ /* MCU Configuration--------------------------------------------------------*/ /* Reset of all peripherals, Initializes the Flash interface and the Systick. */ HAL_Init(); /* USER CODE BEGIN Init */ /* USER CODE END Init */ /* Configure the system clock */ SystemClock_Config(); /* USER CODE BEGIN SysInit */ /* USER CODE END SysInit */ /* Initialize all configured peripherals */ MX_GPIO_Init(); MX_DMA_Init(); MX_USART2_UART_Init(); /* USER CODE BEGIN 2 */ /* Initiate Continuous reception */ StartReception(); /* USER CODE END 2 */ /* Infinite loop */ /* USER CODE BEGIN WHILE */ while (1) { /* USER CODE END WHILE */ /* USER CODE BEGIN 3 */ }while (1) { ... } /* USER CODE END 3 */ }{ ... } /** * @brief System Clock Configuration * @retval None *//* ... */ void SystemClock_Config(void) { RCC_OscInitTypeDef RCC_OscInitStruct = {0}; RCC_ClkInitTypeDef RCC_ClkInitStruct = {0}; /** Configure the main internal regulator output voltage *//* ... */ __HAL_RCC_PWR_CLK_ENABLE(); __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1); /** Initializes the RCC Oscillators according to the specified parameters * in the RCC_OscInitTypeDef structure. *//* ... */ RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI; RCC_OscInitStruct.HSIState = RCC_HSI_ON; RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT; RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON; RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI; RCC_OscInitStruct.PLL.PLLM = 16; RCC_OscInitStruct.PLL.PLLN = 360; RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2; RCC_OscInitStruct.PLL.PLLQ = 7; RCC_OscInitStruct.PLL.PLLR = 6; if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) { Error_Handler(); }if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) { ... } /** Activate the Over-Drive mode *//* ... */ if (HAL_PWREx_EnableOverDrive() != HAL_OK) { Error_Handler(); }if (HAL_PWREx_EnableOverDrive() != HAL_OK) { ... } /** Initializes the CPU, AHB and APB buses clocks *//* ... */ RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2; RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4; RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1; if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK) { Error_Handler(); }if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK) { ... } }{ ... } /** * @brief USART2 Initialization Function * @param None * @retval None *//* ... */ static void MX_USART2_UART_Init(void) { /* USER CODE BEGIN USART2_Init 0 */ /* USER CODE END USART2_Init 0 */ /* USER CODE BEGIN USART2_Init 1 */ /* USER CODE END USART2_Init 1 */ huart2.Instance = USART2; huart2.Init.BaudRate = 115200; huart2.Init.WordLength = UART_WORDLENGTH_8B; huart2.Init.StopBits = UART_STOPBITS_1; huart2.Init.Parity = UART_PARITY_NONE; huart2.Init.Mode = UART_MODE_TX_RX; huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE; huart2.Init.OverSampling = UART_OVERSAMPLING_16; if (HAL_UART_Init(&huart2) != HAL_OK) { Error_Handler(); }if (HAL_UART_Init(&huart2) != HAL_OK) { ... } /* USER CODE BEGIN USART2_Init 2 */ /* USER CODE END USART2_Init 2 */ }{ ... } /** * Enable DMA controller clock *//* ... */ static void MX_DMA_Init(void) { /* DMA controller clock enable */ __HAL_RCC_DMA1_CLK_ENABLE(); /* DMA interrupt init */ /* DMA1_Stream5_IRQn interrupt configuration */ HAL_NVIC_SetPriority(DMA1_Stream5_IRQn, 0, 0); HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn); }{ ... } /** * @brief GPIO Initialization Function * @param None * @retval None *//* ... */ static void MX_GPIO_Init(void) { /* GPIO Ports Clock Enable */ __HAL_RCC_GPIOA_CLK_ENABLE(); }{ ... } /* USER CODE BEGIN 4 */ /** * @brief Send Txt information message on UART Tx line (to PC Com port). * @param huart UART handle. * @param String String to be sent to user display * @param Size Size of string * @retval None *//* ... */ void PrintInfo(UART_HandleTypeDef *huart, uint8_t *String, uint16_t Size) { if (HAL_OK != HAL_UART_Transmit(huart, String, Size, 100)) { Error_Handler(); }if (HAL_OK != HAL_UART_Transmit(huart, String, Size, 100)) { ... } }{ ... } /** * @brief This function prints user info on PC com port and initiates RX transfer * @retval None *//* ... */ void StartReception(void) { /* Initializes Buffer swap mechanism (used in User callback) : - 2 physical buffers aRXBufferA and aRXBufferB (RX_BUFFER_SIZE length) *//* ... */ pBufferReadyForReception = aRXBufferA; pBufferReadyForUser = aRXBufferB; uwNbReceivedChars = 0; /* Print user info on PC com port */ PrintInfo(&huart2, aTextInfoStart, COUNTOF(aTextInfoStart)); /* Initializes Rx sequence using Reception To Idle event API. As DMA channel associated to UART Rx is configured as Circular, reception is endless. If reception has to be stopped, call to HAL_UART_AbortReceive() could be used. Use of HAL_UARTEx_ReceiveToIdle_DMA service, will generate calls to user defined HAL_UARTEx_RxEventCallback callback for each occurrence of following events : - DMA RX Half Transfer event (HT) - DMA RX Transfer Complete event (TC) - IDLE event on UART Rx line (indicating a pause is UART reception flow) *//* ... */ if (HAL_OK != HAL_UARTEx_ReceiveToIdle_DMA(&huart2, aRXBufferUser, RX_BUFFER_SIZE)) { Error_Handler(); }if (HAL_OK != HAL_UARTEx_ReceiveToIdle_DMA(&huart2, aRXBufferUser, RX_BUFFER_SIZE)) { ... } }{ ... } /** * @brief This function handles buffer containing received data on PC com port * @note In this example, received data are sent back on UART Tx (loopback) * Any other processing such as copying received data in a larger buffer to make it * available for application, could be implemented here. * @note This routine is executed in Interrupt context. * @param huart UART handle. * @param pData Pointer on received data buffer to be processed * @retval Size Nb of received characters available in buffer *//* ... */ void UserDataTreatment(UART_HandleTypeDef *huart, uint8_t* pData, uint16_t Size) { /* * This function might be called in any of the following interrupt contexts : * - DMA TC and HT events * - UART IDLE line event * * pData and Size defines the buffer where received data have been copied, in order to be processed. * During this processing of already received data, reception is still ongoing. * *//* ... */ uint8_t* pBuff = pData; uint8_t i; /* Implementation of loopback is on purpose implemented in direct register access, in order to be able to echo received characters as fast as they are received. Wait for TC flag to be raised at end of transmit is then removed, only TXE is checked *//* ... */ for (i = 0; i < Size; i++) { while (!(__HAL_UART_GET_FLAG(huart, UART_FLAG_TXE))) {} huart->Instance->DR = *pBuff; pBuff++; }for (i = 0; i < Size; i++) { ... } }{ ... } /** * @brief User implementation of the Reception Event Callback * (Rx event notification called after use of advanced reception service). * @param huart UART handle * @param Size Number of data available in application reception buffer (indicates a position in * reception buffer until which, data are available) * @retval None *//* ... */ void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size) { static uint8_t old_pos = 0; uint8_t *ptemp; uint8_t i; /* Check if number of received data in recpetion buffer has changed */ if (Size != old_pos) { /* Check if position of index in reception buffer has simply be increased of if end of buffer has been reached *//* ... */ if (Size > old_pos) { /* Current position is higher than previous one */ uwNbReceivedChars = Size - old_pos; /* Copy received data in "User" buffer for evacuation */ for (i = 0; i < uwNbReceivedChars; i++) { pBufferReadyForUser[i] = aRXBufferUser[old_pos + i]; }for (i = 0; i < uwNbReceivedChars; i++) { ... } }if (Size > old_pos) { ... } else { /* Current position is lower than previous one : end of buffer has been reached */ /* First copy data from current position till end of buffer */ uwNbReceivedChars = RX_BUFFER_SIZE - old_pos; /* Copy received data in "User" buffer for evacuation */ for (i = 0; i < uwNbReceivedChars; i++) { pBufferReadyForUser[i] = aRXBufferUser[old_pos + i]; }for (i = 0; i < uwNbReceivedChars; i++) { ... } /* Check and continue with beginning of buffer */ if (Size > 0) { for (i = 0; i < Size; i++) { pBufferReadyForUser[uwNbReceivedChars + i] = aRXBufferUser[i]; }for (i = 0; i < Size; i++) { ... } uwNbReceivedChars += Size; }if (Size > 0) { ... } }else { ... } /* Process received data that has been extracted from Rx User buffer */ UserDataTreatment(huart, pBufferReadyForUser, uwNbReceivedChars); /* Swap buffers for next bytes to be processed */ ptemp = pBufferReadyForUser; pBufferReadyForUser = pBufferReadyForReception; pBufferReadyForReception = ptemp; }if (Size != old_pos) { ... } /* Update old_pos as new reference of position in User Rx buffer that indicates position to which data have been processed *//* ... */ old_pos = Size; }{ ... } /* USER CODE END 4 */ /** * @brief This function is executed in case of error occurrence. * @retval None *//* ... */ void Error_Handler(void) { /* USER CODE BEGIN Error_Handler_Debug */ /* User can add his own implementation to report the HAL error return state */ while (1) { /* Toggle LED2 for error */ BSP_LED_Toggle(LED2); HAL_Delay(500); }while (1) { ... } /* USER CODE END Error_Handler_Debug */ }{ ... } #ifdef USE_FULL_ASSERT /** * @brief Reports the name of the source file and the source line number * where the assert_param error has occurred. * @param file: pointer to the source file name * @param line: assert_param error line source number * @retval None *//* ... */ void assert_failed(uint8_t *file, uint32_t line) { /* USER CODE BEGIN 6 */ /* User can add his own implementation to report the file name and line number, tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) *//* ... */ /* USER CODE END 6 */ }assert_failed (uint8_t *file, uint32_t line) { ... } /* ... */#endif /* USE_FULL_ASSERT */