最近把 MDK 升級到了 V5.25 ，發(fā)現(xiàn) Managing Run-Time Environment 中已經(jīng)有好多好多的庫。相比之前已經(jīng)好了太多太多，從底層驅(qū)動，到上層協(xié)議棧，常用的有不常用的也有。發(fā)現(xiàn) ARM 對這套系統(tǒng)的更新速度加快了一些，覺得有必要學(xué)習(xí)一下。從驅(qū)動開始學(xué)起，先學(xué) USART API 詳細介紹見CMSIS Driver USART API

USART 把收到的數(shù)據(jù)再發(fā)出去程序

/**

******************************************************************************

* @file main.c

* @author XinLi

* @version v1.0

* @date 20-March-2018

* @brief Main program body.

******************************************************************************

* @attention

*

*

*

* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation, either version 3 of the License, or

* (at your option) any later version.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program. If not, see .

*

******************************************************************************

*/

/* Header includes -----------------------------------------------------------*/

#include "stm32f4xx.h"

#include "Driver_USART.h"

#include

/* Macro definitions ---------------------------------------------------------*/

/* Type definitions ----------------------------------------------------------*/

/* Variable declarations -----------------------------------------------------*/

extern ARM_DRIVER_USART Driver_USART1;

/* Variable definitions ------------------------------------------------------*/

static uint8_t rxBuffer[1024] = {0};

static uint8_t txBuffer[1024] = {0};

/* Function declarations -----------------------------------------------------*/

static void USART1_Callback(uint32_t event);

static void SystemClock_Config(void);

/* Function definitions ------------------------------------------------------*/

/**

* @brief Main program.

* @param None.

* @return None.

*/

int main(void)

{

/* STM32F4xx HAL library initialization:

- Configure the Flash prefetch, instruction and Data caches

- Configure the Systick to generate an interrupt each 1 msec

- Set NVIC Group Priority to 4

- Global MSP (MCU Support Package) initialization

*/

HAL_Init();

/* Configure the system clock to 168 MHz */

SystemClock_Config();

Driver_USART1.Initialize(USART1_Callback);

Driver_USART1.PowerControl(ARM_POWER_FULL);

Driver_USART1.Control(ARM_USART_MODE_ASYNCHRONOUS |

ARM_USART_DATA_BITS_8 |

ARM_USART_PARITY_NONE |

ARM_USART_STOP_BITS_1 |

ARM_USART_FLOW_CONTROL_NONE, 115200);

Driver_USART1.Control(ARM_USART_CONTROL_TX, 1);

Driver_USART1.Control(ARM_USART_CONTROL_RX, 1);

Driver_USART1.Receive(rxBuffer, sizeof(rxBuffer));

for(;;)

{

}

}

/**

* @brief USART1 callback function.

* @param event: USART events notification mask.

* @return None.

*/

static void USART1_Callback(uint32_t event)

{

if(event & ARM_USART_EVENT_RX_TIMEOUT)

{

Driver_USART1.Control(ARM_USART_ABORT_RECEIVE, 1);

uint32_t length = Driver_USART1.GetRxCount();

memcpy(txBuffer, rxBuffer, length);

Driver_USART1.Send(txBuffer, length);

Driver_USART1.Receive(rxBuffer, sizeof(rxBuffer));

}

}

/**

* @brief System Clock Configuration

* The system Clock is configured as follow :

* System Clock source = PLL (HSE)

* SYSCLK(Hz) = 168000000

* HCLK(Hz) = 168000000

* AHB Prescaler = 1

* APB1 Prescaler = 4

* APB2 Prescaler = 2

* HSE Frequency(Hz) = 8000000

* PLL_M = 8

* PLL_N = 336

* PLL_P = 2

* PLL_Q = 7

* VDD(V) = 3.3

* Main regulator output voltage = Scale1 mode

* Flash Latency(WS) = 5

* @param None

* @retval None

*/

static void SystemClock_Config(void)

{

RCC_ClkInitTypeDef RCC_ClkInitStruct;

RCC_OscInitTypeDef RCC_OscInitStruct;

/* Enable Power Control clock */

__HAL_RCC_PWR_CLK_ENABLE();

/* The voltage scaling allows optimizing the power consumption when the device is

clocked below the maximum system frequency, to update the voltage scaling value

regarding system frequency refer to product datasheet. */

__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

/* Enable HSE Oscillator and activate PLL with HSE as source */

RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;

RCC_OscInitStruct.HSEState = RCC_HSE_ON;

RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;

RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;

RCC_OscInitStruct.PLL.PLLM = 8;

RCC_OscInitStruct.PLL.PLLN = 336;

RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;

RCC_OscInitStruct.PLL.PLLQ = 7;

HAL_RCC_OscConfig(&RCC_OscInitStruct);

/* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2

clocks dividers */

RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | 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_DIV2;

HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5);

/* STM32F405x/407x/415x/417x Revision Z devices: prefetch is supported */

if (HAL_GetREVID() == 0x1001)

{

/* Enable the Flash prefetch */

__HAL_FLASH_PREFETCH_BUFFER_ENABLE();

}

}