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STM32F3使用USART串口DMA发送数据,使用蓝牙发送

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Author: Wind
OS:  WIN7
IDE:    KEILuvision V5.10.0.2
MCU: STM32 F303 VC T6
一、硬件设计
1.MCU使用USART2,USART2_TX——PA2,USART2_RX——PA3
2.DMA:查看ST官方网站的STM32F3参考手册(官网下载),使用DMA1 Channel7




3.MCU与蓝牙模块连接:


二、程序代码

1.USART配置:查看ST官方固件库手册(官网下载),按顺序进行配置,以下复制原文:

//23.2 USART Firmware driver API description

The following section lists the various functions of the USART library.

23.2.1 How to use this driver

1. Enable peripheral clock using RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE) function for USART1 or using RCC_APB1PeriphClockCmd(RCC_APB1Periph_USARTx, ENABLE) function for USART2, USART3, UART4 and UART5.

2. According to the USART mode, enable the GPIO clocks using RCC_AHBPeriphClockCmd() function. (The I/O can be TX, RX, CTS, or and SCLK). 3. Peripheral's alternate function:  Connect the pin to the desired peripherals' Alternate Function (AF) using GPIO_PinAFConfig() function.

 Configure the desired pin in alternate function by: GPIO_InitStruct->GPIO_Mode=

GPIO_Mode_AF.

 Select the type, pull-up/pull-down and output speed via GPIO_PuPd,

GPIO_OType and GPIO_Speed members.

 Call GPIO_Init() function.

4. Program the Baud Rate, Word Length , Stop Bit, Parity, Hardware flow control and

Mode(Receiver/Transmitter) using the SPI_Init() function.

5. For synchronous mode, enable the clock and program the polarity, phase and last bit

using the USART_ClockInit() function.

6. Enable the NVIC and the corresponding interrupt using the function

USART_ITConfig() if you need to use interrupt mode.

7. When using the DMA mode:

 Configure the DMA using DMA_Init() function.

 Active the needed channel Request using USART_DMACmd() function.

8. Enable the USART using the USART_Cmd() function.

9. Enable the DMA using the DMA_Cmd() function, when using DMA mode.

2.DMA配置

//9.2 DMA Firmware driver API description

     The following section lists the various functions of the DMA library.

     9.2.1 How to use this driver

1. Enable The DMA controller clock using RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE) function for DMA1 or using    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE) function for DMA2.

2. Enable and configure the peripheral to be connected to the DMA channel (except for internal SRAM / FLASH memories: no initialization is necessary).

3. For a given Channel, program the Source and Destination addresses, the transfer Direction, the Buffer Size, the Peripheral and Memory Incrementation mode and Data Size, the Circular or Normal mode, the channel transfer Priority and the Memory- to- Memory transfer mode (if needed) using the DMA_Init() function.

4. Enable the NVIC and the corresponding interrupt(s) using the function DMA_ITConfig() if you need to use DMA interrupts.

5. Enable the DMA channel using the DMA_Cmd() function.

6. Activate the needed channel Request using PPP_DMACmd() function for any PPP peripheral except internal SRAM and FLASH (ie. SPI, USART ...) The function allowing this operation is provided in each PPP peripheral driver (ie. SPI_DMACmd for SPI peripheral).

7. Optionally, you can configure the number of data to be transferred when the channel is disabled (ie. after each Transfer Complete event or when a Transfer Error occurs) using the function DMA_SetCurrDataCounter(). And you can get the number of remaining data to be transferred using the function DMA_GetCurrDataCounter() at run time (when the DMA channel is enabled and running).

8. To control DMA events you can use one of the following two methods:

a. Check on DMA channel flags using the function DMA_GetFlagStatus().

b. Use DMA interrupts through the function DMA_ITConfig() at initialization phase and DMA_GetITStatus() function into interrupt routines in communication phase. After checking on a flag you should clear it using DMA_ClearFlag() function. And after checking on an interrupt event you should clear it using DMA_ClearITPendingBit() function.

3.开始发送,使能各功能模块

源代码:
  1. // Header:

  2. // File Name: main.h

  3. // Author: Wind

  4. // Date: 2015.01.25



  5. #ifndef MAIN_H

  6. #define MAIN_H

  7. #include "stm32f30x.h"

  8. #include "stm32f30x_rcc.h"

  9. #include "stm32f30x_dma.h"

  10. #include "Config.h"

  11. #endif





  12. // Header:

  13. // File Name: main.c

  14. // Author: Wind

  15. // Date: 2015.01.25



  16. #include "main.h"

  17. #define BT_TX_BUFFER_LENGTH 26 //发送26个字母

  18. static uint8_t BT_TX_Buffer[BT_TX_BUFFER_LENGTH];



  19. int main()

  20. {

  21. uint8_t i=0,data='A';

  22. BTUSARTConfig(115200);//波特率115200

  23. BTDMAConfig((uint32_t) BT_TX_Buffer,BT_TX_BUFFER_LENGTH);

  24. //准备好待发送数据

  25. for (i=0;i

  26. {

  27. BT_TX_Buffer[i] = data;

  28. }

  29. //开始发送

  30. StartDataTransfer();

  31. while(1);  //连续发送,同时CPU可以做其他事情



  32. }





  33. // Header:

  34. // File Name: Config.h

  35. // Author: Wind

  36. // Date: 2015.01.25



  37. #ifndef CONFIG_H

  38. #define CONFIG_H

  39. #include "stm32f30x.h"

  40. #include "stm32f30x_rcc.h"

  41. #include "stm32f30x_dma.h"

  42. // Bluetooth port settings

  43. #define BT_USART_IO_PORT GPIOA

  44. #define BT_TX_PIN GPIO_Pin_2

  45. #define BT_RX_PIN GPIO_Pin_3

  46. #define BT_TX_SOURCE GPIO_PinSource2

  47. #define BT_RX_SOURCE GPIO_PinSource3

  48. #define BT_USART_GPIO_CLK RCC_AHBPeriph_GPIOA

  49. #define BT_USART_CLK RCC_APB1Periph_USART2

  50. #define BT_TX_AF GPIO_AF_USART2

  51. #define BT_RX_AF GPIO_AF_USART2

  52. #define GPIO_AF_USART2 GPIO_AF_7

  53. #define BT_USART_PORT USART2

  54. #define BT_USART_TDR_ADDRESS ((uint32_t)USART2 + 0x28)

  55. #define BT_USART_RDR_ADDRESS ((uint32_t)USART2 + 0x24)

  56. #define BT_USART_DMA_PORT DMA1

  57. #define BT_USART_DMA_CLK RCC_AHBPeriph_DMA1

  58. #define BT_USART_TX_DMA_CHANNEL DMA1_Channel7

  59. #define BT_USART_RX_DMA_CHANNEL DMA1_Channel6

  60. #define BT_USART_TX_DMA_FLAG_TCIF DMA1_FLAG_TC7

  61. #define BT_USART_RX_DMA_FLAG_TCIF DMA1_FLAG_TC6

  62. //Function declaration

  63. void BTUSARTConfig(uint32_t baudrate);

  64. void BTDMAConfig(uint32_t DataAddr,uint8_t dataLength);

  65. void StartDataTransfer(void);

  66. #endif





  67. // Header:

  68. // File Name: Config.c

  69. // Author: Wind

  70. // Date: 2015.01.25



  71. #include "Config.h"



  72. //USART配置

  73. void BTUSARTConfig(uint32_t baudrate)

  74. {

  75. USART_InitTypeDef USART_InitStructure;

  76. GPIO_InitTypeDef GPIO_InitStructure;

  77. RCC_AHBPeriphClockCmd(BT_USART_GPIO_CLK, ENABLE);

  78. RCC_APB1PeriphClockCmd(BT_USART_CLK, ENABLE);

  79. GPIO_InitStructure.GPIO_Pin = (BT_TX_PIN | BT_RX_PIN);

  80. GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;              //¸′óÃÄ£ê½

  81. GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  82. GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

  83. GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

  84. GPIO_Init(BT_USART_IO_PORT, &GPIO_InitStructure);

  85. GPIO_PinAFConfig(BT_USART_IO_PORT, BT_TX_SOURCE, BT_TX_AF);//ÅäÖÃòy½Åμĸ′óÃ1|Äü

  86. GPIO_PinAFConfig(BT_USART_IO_PORT, BT_RX_SOURCE, BT_RX_AF);

  87. USART_InitStructure.USART_BaudRate = baudrate;

  88. USART_InitStructure.USART_WordLength = USART_WordLength_8b;

  89. USART_InitStructure.USART_StopBits = USART_StopBits_1;

  90. USART_InitStructure.USART_Parity = USART_Parity_No;

  91. USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;

  92. USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

  93. USART_DeInit(BT_USART_PORT);

  94. USART_Init(BT_USART_PORT, &USART_InitStructure);

  95. USART_Cmd(BT_USART_PORT, ENABLE);

  96. }

  97. //DMA配置

  98. //para:dataAddr:Transffer data address;dataLength:Transffer data length

  99. void BTDMAConfig(uint32_t dataAddr,uint8_t dataLength)

  100. {

  101. DMA_InitTypeDef DMA_InitStructure;

  102. RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);

  103. DMA_StructInit(&DMA_InitStructure);

  104. DMA_DeInit(BT_USART_TX_DMA_CHANNEL);

  105. DMA_InitStructure.DMA_PeripheralBaseAddr = BT_USART_TDR_ADDRESS;

  106. DMA_InitStructure.DMA_MemoryBaseAddr = dataAddr;

  107. DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;         //外设作为发送目的地

  108. DMA_InitStructure.DMA_BufferSize = dataLength;

  109. DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

  110. DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

  111. DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;

  112. DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;

  113. DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; //循环发送模式

  114. DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;

  115. DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

  116. DMA_Init(BT_USART_TX_DMA_CHANNEL,&DMA_InitStructure);

  117. }

  118. //开始发送

  119. void StartDataTransfer(void)

  120. {

  121. //清除标志位,否则可能丢失数据

  122. USART_ClearFlag(BT_USART_PORT,USART_FLAG_TC);

  123. DMA_ClearFlag(BT_USART_TX_DMA_FLAG_TCIF);

  124. //发送

  125. USART_DMACmd(BT_USART_PORT,USART_DMAReq_Tx,ENABLE);

  126. DMA_Cmd(BT_USART_TX_DMA_CHANNEL,ENABLE);

  127. //等待发送完毕

  128. while (!DMA_GetFlagStatus(BT_USART_TX_DMA_FLAG_TCIF));

  129. }
复制代码




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