步骤2:现在我们将使用STM32F030R8T6的2个GPIO。在本教程中，我们实现了按钮切换LED。

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本项目采用STM32 CubeMX软件制作，IDE是Keil，硬件方面我使用的是STM32F0 Nucleo板。在这个例子中，我们使用板载LED和按钮。
在这个项目中，我们实现了两个GPIOs。1为LED输出2。将按钮作为输入。在本例项目中，当用户按下按钮时，LED将打开。
% m. m7 N- F9 P; U' t# Kbb0每一个GPIO引脚都可以通过软件配置为输出(推拉或开漏)、输入(带或不带上拉或下拉)或外设替代功能。
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6 Q) S. r1 E6 R8 c& }5 B输入配置基础:
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  A9 w' b+ I) {: H/ ~# f当I/O端口被编程为输入时:

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• 输出缓冲区被禁用
• 激活Schmitt触发器输入
• 根据GPIOx_PUPDR寄存器中的值激活上拉和下拉电阻
• 
• 在每个AHB时钟周期中，I/O引脚上的数据被采样到输入数据寄存器中
• 对输入数据寄存器的读访问提供I/O状态
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---

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代码：
按下按钮Main.c文件/ c++
如果代码无法工作，将此cose复制到main.c文件中。任何问题都要告诉我。
在USER code BEGIN 3下编写代码。
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1. /**
   
2.   ******************************************************************************
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3.   * @file           : main.c
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4.   * @brief          : Main program body
   
5.   ******************************************************************************
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6.   ** This notice applies to any and all portions of this file
   * K& D% k. l9 E) U1 S; x
7.   * that are not between comment pairs USER CODE BEGIN and
   
8.   * USER CODE END. Other portions of this file, whether
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9.   * inserted by the user or by software development tools
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10.   * are owned by their respective copyright owners.
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11.   *
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12.   * COPYRIGHT(c) 2018 STMicroelectronics
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13.   *
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14.   * Redistribution and use in source and binary forms, with or without modification,
    
15.   * are permitted provided that the following conditions are met:
    
16.   *   1. Redistributions of source code must retain the above copyright notice,
    
17.   *      this list of conditions and the following disclaimer.
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18.   *   2. Redistributions in binary form must reproduce the above copyright notice,
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19.   *      this list of conditions and the following disclaimer in the documentation
    
20.   *      and/or other materials provided with the distribution.
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21.   *   3. Neither the name of STMicroelectronics nor the names of its contributors
    
22.   *      may be used to endorse or promote products derived from this software
    
23.   *      without specific prior written permission.
    
24.   *
    
25.   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    
26.   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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27.   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    
28.   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
    
29.   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    
30.   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    
31.   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    
32.   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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33.   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    
34.   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    
35.   *
    
36.   ******************************************************************************
    
37.   */
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38. /* Includes ------------------------------------------------------------------*/
    
39. #include "main.h"
    
40. #include "stm32f0xx_hal.h"
    
41. #include "gpio.h"
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42. 
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43. /* USER CODE BEGIN Includes */
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44. 
    
45. /* USER CODE END Includes */
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46. 
    
47. /* Private variables ---------------------------------------------------------*/
    
48. 
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49. /* USER CODE BEGIN PV */
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50. /* Private variables ---------------------------------------------------------*/
    
51. 
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52. /* USER CODE END PV */
    
53. 
    
54. /* Private function prototypes -----------------------------------------------*/
    
55. void SystemClock_Config(void);
    
56. 
    
57. /* USER CODE BEGIN PFP */
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58. /* Private function prototypes -----------------------------------------------*/
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59. 
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60. /* USER CODE END PFP */
    
61. 
    
62. /* USER CODE BEGIN 0 */
    
63. 
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64. /* USER CODE END 0 */
    
65. 
    
66. /**
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67.   * @brief  The application entry point.
    
68.   *
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69.   * @retval None
    
70.   */
    
71. int main(void)
    
72. {
    
73.   /* USER CODE BEGIN 1 */
    
74. 
    
75.   /* USER CODE END 1 */
    
76. 
    
77.   /* MCU Configuration----------------------------------------------------------*/
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78. 
    
79.   /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
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80.   HAL_Init();
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81. 
    
82.   /* USER CODE BEGIN Init */
    
83. 
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84.   /* USER CODE END Init */
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85. 
    
86.   /* Configure the system clock */
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87.   SystemClock_Config();
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88. 
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89.   /* USER CODE BEGIN SysInit */
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90. 
    
91.   /* USER CODE END SysInit */
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92. 
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93.   /* Initialize all configured peripherals */
    
94.   MX_GPIO_Init();
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95.   /* USER CODE BEGIN 2 */
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96. 
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97.   /* USER CODE END 2 */
    
98. 
    
99.   /* Infinite loop */
    
100.   /* USER CODE BEGIN WHILE */
     
101.   while (1)
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102.   {
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103. 
     
104.   /* USER CODE END WHILE */
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105. 
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106.   /* USER CODE BEGIN 3 */
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107. if(HAL_GPIO_ReadPin(GPIOC,GPIO_PIN_3)==GPIO_PIN_SET)
     
108. {
     
109.         HAL_GPIO_WritePin(GPIOA,GPIO_PIN_5, GPIO_PIN_SET);
     
110. }
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111. else
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112. {
     
113.         HAL_GPIO_WritePin(GPIOA,GPIO_PIN_5,GPIO_PIN_RESET);
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114.   }
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115.   /* USER CODE END 3 */
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116. 
     
117. }
     
118. 
     
119. /**
     
120.   * @brief System Clock Configuration
     
121.   * @retval None
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122.   */
     
123. void SystemClock_Config(void)
     
124. {
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125. 
     
126.   RCC_OscInitTypeDef RCC_OscInitStruct;
     
127.   RCC_ClkInitTypeDef RCC_ClkInitStruct;
     
128. 
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129.     /**Initializes the CPU, AHB and APB busses clocks
     
130.     */
     
131.   RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
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132.   RCC_OscInitStruct.HSIState = RCC_HSI_ON;
     
133.   RCC_OscInitStruct.HSICalibrationValue = 16;
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134.   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
     
135.   if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
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136.   {
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137.     _Error_Handler(__FILE__, __LINE__);
     
138.   }
     
139. 
     
140.     /**Initializes the CPU, AHB and APB busses clocks
     
141.     */
     
142.   RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
     
143.                               |RCC_CLOCKTYPE_PCLK1;
     
144.   RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
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145.   RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
     
146.   RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
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147. 
     
148.   if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
     
149.   {
     
150.     _Error_Handler(__FILE__, __LINE__);
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151.   }
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152. 
     
153.     /**Configure the Systick interrupt time
     
154.     */
     
155.   HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);
     
156. 
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157.     /**Configure the Systick
     
158.     */
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159.   HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
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160. 
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161.   /* SysTick_IRQn interrupt configuration */
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162.   HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
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163. }
     
164. 
     
165. /* USER CODE BEGIN 4 */
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166. 
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167. /* USER CODE END 4 */
     
168. 
     
169. /**
     
170.   * @brief  This function is executed in case of error occurrence.
     
171.   * @param  file: The file name as string.
     
172.   * @param  line: The line in file as a number.
     
173.   * @retval None
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174.   */
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175. void _Error_Handler(char *file, int line)
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176. {
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177.   /* USER CODE BEGIN Error_Handler_Debug */
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178.   /* User can add his own implementation to report the HAL error return state */
     
179.   while(1)
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180.   {
     
181.   }
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182.   /* USER CODE END Error_Handler_Debug */
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183. }
     
184. 
     
185. #ifdef  USE_FULL_ASSERT
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186. /**
     
187.   * @brief  Reports the name of the source file and the source line number
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188.   *         where the assert_param error has occurred.
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189.   * @param  file: pointer to the source file name
     
190.   * @param  line: assert_param error line source number
     
191.   * @retval None
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192.   */
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193. void assert_failed(uint8_t* file, uint32_t line)
     
194. {
     
195.   /* USER CODE BEGIN 6 */
     
196.   /* User can add his own implementation to report the file name and line number,
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197.      tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
     
198.   /* USER CODE END 6 */
     
199. }
     
200. #endif /* USE_FULL_ASSERT */
     
201. 
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202. /**
     
203.   * @}
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204.   */
     
205. 
     
206. /**
     
207.   * @}
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208.   */
     
209. 
     
210. /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

复制代码

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) v% {9 Q- S8 \: x7 A原创：Ashish Maheshwari
出处：http://www.hackster.io/ashish205/stm32f0-push-button-to-switch-on-led-bc9958
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