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/**
******************************************************************************
* @file Examples_LL/USART/USART_Communication_TxRx_DMA/Src/main.c
* @author MCD Application Team
* @brief This example describes how to send/receive bytes over USART IP using
* the STM32F4xx USART LL API in DMA mode.
* Peripheral initialization done using LL unitary services functions.
******************************************************************************
* @attention
*
* Copyright (c) 2017 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.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/** @addtogroup STM32F4xx_LL_Examples
* @{
*/
/** @addtogroup USART_Communication_TxRx_DMA
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
__IO uint8_t ubButtonPress = 0;
__IO uint8_t ubSend = 0;
/* Buffer used for transmission */
const uint8_t aTxBuffer[] = "STM32F4xx USART LL API Example : TX/RX in DMA mode\r\nConfiguration UART 115200 bps, 8 data bit/1 stop bit/No parity/No HW flow control\r\nPlease enter 'END' string ...\r\n";
uint8_t ubNbDataToTransmit = sizeof(aTxBuffer);
__IO uint8_t ubTransmissionComplete = 0;
/* Buffer used for reception */
const uint8_t aStringToReceive[] = "END";
uint8_t ubNbDataToReceive = sizeof(aStringToReceive) - 1;
uint8_t aRxBuffer[sizeof(aStringToReceive) - 1];
__IO uint8_t ubReceptionComplete = 0;
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
void Configure_DMA(void);
void Configure_USART(void);
void StartTransfers(void);
void LED_Init(void);
void LED_On(void);
void LED_Blinking(uint32_t Period);
void LED_Off(void);
void UserButton_Init(void);
void WaitForUserButtonPress(void);
void WaitAndCheckEndOfTransfer(void);
uint8_t Buffercmp8(uint8_t* pBuffer1, uint8_t* pBuffer2, uint8_t BufferLength);
/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{
/* Configure the system clock to 100 MHz */
SystemClock_Config();
/* Initialize LED2 */
LED_Init();
/* Initialize button in EXTI mode */
UserButton_Init();
/* Configure USARTx (USART IP configuration and related GPIO initialization) */
Configure_USART();
/* Configure DMA channels for USART instance */
Configure_DMA();
/* Wait for User push-button press to start transfer */
WaitForUserButtonPress();
/* Initiate DMA transfers */
StartTransfers();
/* Wait for the end of the transfer and check received data */
WaitAndCheckEndOfTransfer();
/* Infinite loop */
while (1)
{
}
}
/**
* @brief This function configures the DMA Channels for TX and RX transfers
* @note This function is used to :
* -1- Enable DMA1 clock
* -2- Configure NVIC for DMA transfer complete/error interrupts
* -3- Configure DMA TX channel functional parameters
* -4- Configure DMA RX channel functional parameters
* -5- Enable transfer complete/error interrupts
* @param None
* @retval None
*/
void Configure_DMA(void)
{
/* DMA1 used for USART2 Transmission and Reception
*/
/* (1) Enable the clock of DMA1 */
LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_DMA1);
/* (2) Configure NVIC for DMA transfer complete/error interrupts */
NVIC_SetPriority(DMA1_Stream6_IRQn, 0);
NVIC_EnableIRQ(DMA1_Stream6_IRQn);
NVIC_SetPriority(DMA1_Stream7_IRQn, 0);
NVIC_EnableIRQ(DMA1_Stream7_IRQn);
/* (3) Configure the DMA functional parameters for transmission */
LL_DMA_SetChannelSelection(DMA1, LL_DMA_STREAM_6, LL_DMA_CHANNEL_4);
LL_DMA_ConfigTransfer(DMA1, LL_DMA_STREAM_6,
LL_DMA_DIRECTION_MEMORY_TO_PERIPH |
LL_DMA_PRIORITY_HIGH |
LL_DMA_MODE_NORMAL |
LL_DMA_PERIPH_NOINCREMENT |
LL_DMA_MEMORY_INCREMENT |
LL_DMA_PDATAALIGN_BYTE |
LL_DMA_MDATAALIGN_BYTE);
LL_DMA_ConfigAddresses(DMA1, LL_DMA_STREAM_6,
(uint32_t)aTxBuffer,
LL_USART_DMA_GetRegAddr(USART2),
LL_DMA_GetDataTransferDirection(DMA1, LL_DMA_STREAM_6));
LL_DMA_SetDataLength(DMA1, LL_DMA_STREAM_6, ubNbDataToTransmit);
/* (4) Configure the DMA functional parameters for reception */
LL_DMA_SetChannelSelection(DMA1, LL_DMA_STREAM_7, LL_DMA_CHANNEL_6);
LL_DMA_ConfigTransfer(DMA1, LL_DMA_STREAM_7,
LL_DMA_DIRECTION_PERIPH_TO_MEMORY |
LL_DMA_PRIORITY_HIGH |
LL_DMA_MODE_NORMAL |
LL_DMA_PERIPH_NOINCREMENT |
LL_DMA_MEMORY_INCREMENT |
LL_DMA_PDATAALIGN_BYTE |
LL_DMA_MDATAALIGN_BYTE);
LL_DMA_ConfigAddresses(DMA1, LL_DMA_STREAM_7,
LL_USART_DMA_GetRegAddr(USART2),
(uint32_t)aRxBuffer,
LL_DMA_GetDataTransferDirection(DMA1, LL_DMA_STREAM_7));
LL_DMA_SetDataLength(DMA1, LL_DMA_STREAM_7, ubNbDataToReceive);
/* (5) Enable DMA transfer complete/error interrupts */
LL_DMA_EnableIT_TC(DMA1, LL_DMA_STREAM_6);
LL_DMA_EnableIT_TE(DMA1, LL_DMA_STREAM_6);
LL_DMA_EnableIT_TC(DMA1, LL_DMA_STREAM_7);
LL_DMA_EnableIT_TE(DMA1, LL_DMA_STREAM_7);
}
/**
* @brief This function configures USARTx Instance.
* @note This function is used to :
* -1- Enable GPIO clock and configures the USART2 pins.
* -2- Enable the USART2 peripheral clock and clock source.
* -3- Configure USART2 functional parameters.
* -4- Enable USART2.
* @note Peripheral configuration is minimal configuration from reset values.
* Thus, some useless LL unitary functions calls below are provided as
* commented examples - setting is default configuration from reset.
* @param None
* @retval None
*/
void Configure_USART(void)
{
/* (1) Enable GPIO clock and configures the USART pins **********************/
/* Enable the peripheral clock of GPIO Port */
LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOA);
/* Configure Tx Pin as : Alternate function, High Speed, Push pull, Pull up */
LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_2, LL_GPIO_MODE_ALTERNATE);
LL_GPIO_SetAFPin_0_7(GPIOA, LL_GPIO_PIN_2, LL_GPIO_AF_7);
LL_GPIO_SetPinSpeed(GPIOA, LL_GPIO_PIN_2, LL_GPIO_SPEED_FREQ_HIGH);
LL_GPIO_SetPinOutputType(GPIOA, LL_GPIO_PIN_2, LL_GPIO_OUTPUT_PUSHPULL);
LL_GPIO_SetPinPull(GPIOA, LL_GPIO_PIN_2, LL_GPIO_PULL_UP);
/* Configure Rx Pin as : Alternate function, High Speed, Push pull, Pull up */
LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_3, LL_GPIO_MODE_ALTERNATE);
LL_GPIO_SetAFPin_0_7(GPIOA, LL_GPIO_PIN_3, LL_GPIO_AF_7);
LL_GPIO_SetPinSpeed(GPIOA, LL_GPIO_PIN_3, LL_GPIO_SPEED_FREQ_HIGH);
LL_GPIO_SetPinOutputType(GPIOA, LL_GPIO_PIN_3, LL_GPIO_OUTPUT_PUSHPULL);
LL_GPIO_SetPinPull(GPIOA, LL_GPIO_PIN_3, LL_GPIO_PULL_UP);
/* (2) Enable USART2 peripheral clock and clock source ****************/
LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_USART2);
/* (3) Configure USART2 functional parameters ********************************/
/* Disable USART prior modifying configuration registers */
/* Note: Commented as corresponding to Reset value */
// LL_USART_Disable(USART2);
/* TX/RX direction */
LL_USART_SetTransferDirection(USART2, LL_USART_DIRECTION_TX_RX);
/* 8 data bit, 1 start bit, 1 stop bit, no parity */
LL_USART_ConfigCharacter(USART2, LL_USART_DATAWIDTH_8B, LL_USART_PARITY_NONE, LL_USART_STOPBITS_1);
/* No Hardware Flow control */
/* Reset value is LL_USART_HWCONTROL_NONE */
// LL_USART_SetHWFlowCtrl(USART2, LL_USART_HWCONTROL_NONE);
/* Oversampling by 16 */
/* Reset value is LL_USART_OVERSAMPLING_16 */
// LL_USART_SetOverSampling(USART2, LL_USART_OVERSAMPLING_16);
/* Set Baudrate to 115200 using APB frequency set to 500000000 Hz */
/* Frequency available for USART peripheral can also be calculated through LL RCC macro */
/* Ex :
Periphclk = LL_RCC_GetUSARTClockFreq(Instance); or LL_RCC_GetUARTClockFreq(Instance); depending on USART/UART instance
In this example, Peripheral Clock is expected to be equal to 500000000 Hz => equal to SystemCoreClock/2
*/
LL_USART_SetBaudRate(USART2, SystemCoreClock/2, LL_USART_OVERSAMPLING_16, 115200);
/* (4) Enable USART2 **********************************************************/
LL_USART_Enable(USART2);
}
/**
* @brief This function initiates TX and RX DMA transfers by enabling DMA channels
* @param None
* @retval None
*/
void StartTransfers(void)
{
/* Enable DMA RX Interrupt */
LL_USART_EnableDMAReq_RX(USART2);
/* Enable DMA TX Interrupt */
LL_USART_EnableDMAReq_TX(USART2);
/* Enable DMA Channel Rx */
LL_DMA_EnableStream(DMA1, LL_DMA_STREAM_7);
/* Enable DMA Channel Tx */
LL_DMA_EnableStream(DMA1, LL_DMA_STREAM_6);
}
/**
* @brief Initialize LED2.
* @param None
* @retval None
*/
void LED_Init(void)
{
/* Enable the LED2 Clock */
LED2_GPIO_CLK_ENABLE();
/* Configure IO in output push-pull mode to drive external LED2 */
LL_GPIO_SetPinMode(LED2_GPIO_PORT, LED2_PIN, LL_GPIO_MODE_OUTPUT);
/* Reset value is LL_GPIO_OUTPUT_PUSHPULL */
//LL_GPIO_SetPinOutputType(LED2_GPIO_PORT, LED2_PIN, LL_GPIO_OUTPUT_PUSHPULL);
/* Reset value is LL_GPIO_SPEED_FREQ_LOW */
//LL_GPIO_SetPinSpeed(LED2_GPIO_PORT, LED2_PIN, LL_GPIO_SPEED_FREQ_LOW);
/* Reset value is LL_GPIO_PULL_NO */
//LL_GPIO_SetPinPull(LED2_GPIO_PORT, LED2_PIN, LL_GPIO_PULL_NO);
}
/**
* @brief Turn-on LED2.
* @param None
* @retval None
*/
void LED_On(void)
{
/* Turn LED2 on */
LL_GPIO_SetOutputPin(LED2_GPIO_PORT, LED2_PIN);
}
/**
* @brief Turn-off LED2.
* @param None
* @retval None
*/
void LED_Off(void)
{
/* Turn LED2 off */
LL_GPIO_ResetOutputPin(LED2_GPIO_PORT, LED2_PIN);
}
/**
* @brief Set LED2 to Blinking mode for an infinite loop (toggle period based on value provided as input parameter).
* @param Period : Period of time (in ms) between each toggling of LED
* This parameter can be user defined values. Pre-defined values used in that example are :
* @arg LED_BLINK_FAST : Fast Blinking
* @arg LED_BLINK_SLOW : Slow Blinking
* @arg LED_BLINK_ERROR : Error specific Blinking
* @retval None
*/
void LED_Blinking(uint32_t Period)
{
/* Toggle LED2 in an infinite loop */
while (1)
{
LL_GPIO_TogglePin(LED2_GPIO_PORT, LED2_PIN);
LL_mDelay(Period);
}
}
/**
* @brief Configures User push-button in GPIO or EXTI Line Mode.
* @param None
* @retval None
*/
void UserButton_Init(void)
{
/* Enable the BUTTON Clock */
USER_BUTTON_GPIO_CLK_ENABLE();
/* Configure GPIO for BUTTON */
LL_GPIO_SetPinMode(USER_BUTTON_GPIO_PORT, USER_BUTTON_PIN, LL_GPIO_MODE_INPUT);
LL_GPIO_SetPinPull(USER_BUTTON_GPIO_PORT, USER_BUTTON_PIN, LL_GPIO_PULL_NO);
/* Connect External Line to the GPIO*/
USER_BUTTON_SYSCFG_SET_EXTI();
/* Enable a rising trigger EXTI13 Interrupt */
USER_BUTTON_EXTI_LINE_ENABLE();
USER_BUTTON_EXTI_FALLING_TRIG_ENABLE();
/* Configure NVIC for USER_BUTTON_EXTI_IRQn */
NVIC_SetPriority(USER_BUTTON_EXTI_IRQn, 3);
NVIC_EnableIRQ(USER_BUTTON_EXTI_IRQn);
}
/**
* @brief Wait for User push-button press to start transfer.
* @param None
* @retval None
*/
/* */
void WaitForUserButtonPress(void)
{
while (ubButtonPress == 0)
{
LL_GPIO_TogglePin(LED2_GPIO_PORT, LED2_PIN);
LL_mDelay(LED_BLINK_FAST);
}
/* Ensure that LED2 is turned Off */
LED_Off();
}
/**
* @brief Wait end of transfer and check if received Data are well.
* @param None
* @retval None
*/
void WaitAndCheckEndOfTransfer(void)
{
/* 1 - Wait end of transmission */
while (ubTransmissionComplete != 1)
{
}
/* Disable DMA1 Tx Channel */
LL_DMA_DisableStream(DMA1, LL_DMA_STREAM_6);
/* 2 - Wait end of reception */
while (ubReceptionComplete != 1)
{
}
/* Disable DMA1 Rx Channel */
LL_DMA_DisableStream(DMA1, LL_DMA_STREAM_7);
/* 3 - Compare received string to expected one */
if(Buffercmp8((uint8_t*)aStringToReceive, (uint8_t*)aRxBuffer, ubNbDataToReceive))
{
/* Processing Error */
LED_Blinking(LED_BLINK_ERROR);
}
else
{
/* Turn On Led if data are well received */
LED_On();
}
}
/**
* @brief Compares two 8-bit buffers and returns the comparison result.
* @param pBuffer1: pointer to the source buffer to be compared to.
* @param pBuffer2: pointer to the second source buffer to be compared to the first.
* @param BufferLength: buffer's length.
* @retval 0: Comparison is OK (the two Buffers are identical)
* Value different from 0: Comparison is NOK (Buffers are different)
*/
uint8_t Buffercmp8(uint8_t* pBuffer1, uint8_t* pBuffer2, uint8_t BufferLength)
{
while (BufferLength--)
{
if (*pBuffer1 != *pBuffer2)
{
return 1;
}
pBuffer1++;
pBuffer2++;
}
return 0;
}
/**
* @brief System Clock Configuration
* The system Clock is configured as follow :
* System Clock source = PLL (HSE)
* SYSCLK(Hz) = 100000000
* HCLK(Hz) = 100000000
* AHB Prescaler = 1
* APB1 Prescaler = 2
* APB2 Prescaler = 1
* HSE Frequency(Hz) = 8000000
* PLL_M = 8
* PLL_N = 400
* PLL_P = 4
* VDD(V) = 3.3
* Main regulator output voltage = Scale1 mode
* Flash Latency(WS) = 3
* @param None
* @retval None
*/
void SystemClock_Config(void)
{
/* Enable HSE oscillator */
LL_RCC_HSE_EnableBypass();
LL_RCC_HSE_Enable();
while(LL_RCC_HSE_IsReady() != 1)
{
};
/* Set FLASH latency */
LL_FLASH_SetLatency(LL_FLASH_LATENCY_3);
/* Main PLL configuration and activation */
LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSE, LL_RCC_PLLM_DIV_8, 400, LL_RCC_PLLP_DIV_4);
LL_RCC_PLL_Enable();
while(LL_RCC_PLL_IsReady() != 1)
{
};
/* Sysclk activation on the main PLL */
LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL)
{
};
/* Set APB1 & APB2 prescaler */
LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_2);
LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_1);
/* Set systick to 1ms */
SysTick_Config(100000000 / 1000);
/* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
SystemCoreClock = 100000000;
}
/******************************************************************************/
/* USER IRQ HANDLER TREATMENT Functions */
/******************************************************************************/
/**
* @brief Function to manage User push-button
* @param None
* @retval None
*/
void UserButton_Callback(void)
{
/* Update User push-button variable : to be checked in waiting loop in main program */
ubButtonPress = 1;
}
/**
* @brief Function called from DMA1 IRQ Handler when Tx transfer is completed
* @param None
* @retval None
*/
void DMA1_TransmitComplete_Callback(void)
{
/* DMA Tx transfer completed */
ubTransmissionComplete = 1;
}
/**
* @brief Function called from DMA1 IRQ Handler when Rx transfer is completed
* @param None
* @retval None
*/
void DMA1_ReceiveComplete_Callback(void)
{
/* DMA Rx transfer completed */
ubReceptionComplete = 1;
}
/**
* @brief Function called in case of error detected in USART IT Handler
* @param None
* @retval None
*/
void USART_TransferError_Callback(void)
{
/* Disable DMA1 Tx Channel */
LL_DMA_DisableStream(DMA1, LL_DMA_STREAM_6);
/* Disable DMA1 Rx Channel */
LL_DMA_DisableStream(DMA1, LL_DMA_STREAM_7);
/* Set LED2 to Blinking mode to indicate error occurs */
LED_Blinking(LED_BLINK_ERROR);
}
#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 can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d", file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif
/**
* @}
*/
/**
* @}
*/
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