1 | /*************************
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2 | * stm32 uart main.c
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3 | *************************/
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4 |
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5 | #include "stm32f10x.h"
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6 | #include "print.h"
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7 |
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8 |
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9 | /* User defined function prototypes */
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10 | void GPIOB_Init(void);
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11 | void USART1_Init(void);
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12 | void led_toggle(void);
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13 |
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14 |
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15 | int main(void)
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16 | {
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17 | /* Initialize GPIOA PIN8 */
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18 | GPIOB_Init();
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19 | /* Initialize USART1 */
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20 | USART1_Init();
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21 | printf_("Hello World");
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22 | // USART_SendData(USART1, 'T');
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23 |
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24 | while(1)
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25 | {
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26 | //USART_SendData(USART1, 'T'); /* Do nothing, all happens in ISR */
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27 | }
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28 | }
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29 |
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30 | /***********************************************
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31 | * Initialize GPIOA PIN8 as push-pull output
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32 | ***********************************************/
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33 | void GPIOB_Init(void)
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34 | {
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35 | /* Bit configuration structure for GPIOA PIN8 */
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36 | GPIO_InitTypeDef gpiob_init_struct = { GPIO_Pin_2, GPIO_Speed_50MHz,
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37 | GPIO_Mode_Out_PP };
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38 |
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39 | /* Enable PORT A clock */
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40 | RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
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41 | /* Initialize GPIOA: 50MHz, PIN8, Push-pull Output */
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42 | GPIO_Init(GPIOB, &gpiob_init_struct);
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43 |
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44 | /* Turn off LED to start with */
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45 | GPIO_SetBits(GPIOB, GPIO_Pin_2);
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46 | }
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47 |
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48 | /*****************************************************
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49 | * Initialize USART1: enable interrupt on reception
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50 | * of a character
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51 | *****************************************************/
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52 | void USART1_Init(void)
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53 | {
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54 | /* USART configuration structure for USART1 */
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55 | USART_InitTypeDef usart1_init_struct;
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56 | /* Bit configuration structure for GPIOB PIN6 and PIN7 (alternative function) */
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57 | GPIO_InitTypeDef gpiob_init_struct;
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58 | RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOB, ENABLE);
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59 | GPIO_PinRemapConfig(GPIO_Remap_USART1, ENABLE);
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60 |
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61 | /* Enalbe clock for USART1, AFIO and GPIOA */
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62 |
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63 |
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64 | /* GPIOB PIN6 alternative function Tx */
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65 | gpiob_init_struct.GPIO_Pin = GPIO_Pin_6;
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66 | gpiob_init_struct.GPIO_Speed = GPIO_Speed_50MHz;
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67 | gpiob_init_struct.GPIO_Mode = GPIO_Mode_AF_PP;
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68 | GPIO_Init(GPIOB, &gpiob_init_struct);
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69 | /* GPIOB PIN7 alternative function Rx */
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70 | gpiob_init_struct.GPIO_Pin = GPIO_Pin_7;
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71 | gpiob_init_struct.GPIO_Speed = GPIO_Speed_50MHz;
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72 | gpiob_init_struct.GPIO_Mode = GPIO_Mode_IN_FLOATING;
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73 | GPIO_Init(GPIOB, &gpiob_init_struct);
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74 |
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75 | /* Enable USART1 */
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76 | USART_Cmd(USART1, ENABLE);
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77 | /* Baud rate 9600, 8-bit data, One stop bit
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78 | * No parity, Do both Rx and Tx, No HW flow control
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79 | */
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80 | usart1_init_struct.USART_BaudRate = 9600;
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81 | usart1_init_struct.USART_WordLength = USART_WordLength_8b;
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82 | usart1_init_struct.USART_StopBits = USART_StopBits_1;
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83 | usart1_init_struct.USART_Parity = USART_Parity_No ;
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84 | usart1_init_struct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
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85 | usart1_init_struct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
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86 | /* Configure USART1 */
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87 | USART_Init(USART1, &usart1_init_struct);
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88 | /* Enable RXNE interrupt */
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89 | USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
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90 | /* Enable USART1 global interrupt */
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91 |
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92 | NVIC_EnableIRQ(USART1_IRQn);
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93 |
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94 |
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95 |
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96 | }
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97 |
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98 | /*******************************************
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99 | * Toggle LED
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100 | *******************************************/
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101 | void led_toggle(void)
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102 | {
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103 | /* Read LED output (GPIOA PIN8) status */
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104 | uint8_t led_bit = GPIO_ReadOutputDataBit(GPIOB, GPIO_Pin_2);
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105 |
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106 | /* If LED output set, clear it */
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107 | if(led_bit == (uint8_t)Bit_SET)
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108 | {
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109 | GPIO_ResetBits(GPIOB, GPIO_Pin_2);
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110 | }
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111 | /* If LED output clear, set it */
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112 | else
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113 | {
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114 | GPIO_SetBits(GPIOB, GPIO_Pin_2);
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115 | }
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116 | }
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117 |
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118 | /**********************************************************
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119 | * USART1 interrupt request handler: on reception of a
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120 | * character 't', toggle LED and transmit a character 'T'
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121 | *********************************************************/
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122 | void USART1_IRQHandler(void)
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123 | {
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124 | /* RXNE handler */
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125 | if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
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126 | {
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127 | /* If received 't', toggle LED and transmit 'T' */
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128 | if((char)USART_ReceiveData(USART1) == 't')
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129 | {
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130 | led_toggle();
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131 | USART_SendData(USART1, 'T');
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132 | /* Wait until Tx data register is empty, not really
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133 | * required for this example but put in here anyway.
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134 | */
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135 | /*
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136 | while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET)
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137 | {
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138 | }*/
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139 | }
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140 | }
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141 |
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142 | /* ------------------------------------------------------------ */
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143 | /* Other USART1 interrupts handler can go here ... */
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144 | }
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