STM32

STM32连接到地后将GPIO引脚拉高工作出现的问题

2019-07-14 18:03发布

站内问答 / STM32/STM8
3425 6 1083
我想用STM32_smart v2开发板从GPIO到地面的7个跳线制作廉价可靠的7位输入接口。使用内部上拉电阻。我第一次没有将任何GPIO连接到地面的时候电压显示3.3V。在第一次连接后，我使用的GPIO从1V到2.7V，即使不再连接到地面也是如此。这是为什么？有人能解答一下吗？ 1.png
  1. #include "stm32f10x.h"
  2. //#include "stm32_eval.h"
  3. #include "stm32f10x_gpio.h"
  4. #include "stm32f10x_rcc.h"
  5. #include "stm32f10x_usart.h"
  6. #include "stm32f10x_exti.h"
  7. #include "stm32f10x_tim.h"
  8. #include "stdio.h"
  9. //#include "tm1637.h"
  10. #include "misc.h" /* High level functions for NVIC and SysTick (add-on to CMSIS functions) */


  13. #define TRUE 1
  14. #define FALSE 0
  15. #define NoONE 0
  16. #define TEAM_A 1
  17. #define TEAM_B 2

  19. //Timer ISR sets this flag to communicate with the main program.
  20. static __IO uint8_t TimerEventFlag;   
  21. static __IO uint8_t TimerTicks=0;   
  22. static __IO uint8_t ControlTeam=NoONE;
  23. static __IO unsigned int TeamATime;
  24. static __IO unsigned int TeamBTime;
  25. static __IO unsigned int InitialTime=65;

  27. unsigned int timeformat(unsigned int seconds){
  28.     unsigned int min=0;
  29.     unsigned int sec=0;
  30.     min=(seconds/60);
  31.     sec=seconds%60;
  32.     return min*100+sec;
  33. }

  35. void Configure_DIP(void){
  36.     GPIO_InitTypeDef GPIO_InitStruct;
  37.         /* Set pin as input */
  38.     GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IPU;
  39.     GPIO_InitStruct.GPIO_Pin = GPIO_Pin_10|GPIO_Pin_9|GPIO_Pin_8;
  40.     GPIO_InitStruct.GPIO_Speed = GPIO_Speed_2MHz;
  41.     GPIO_Init(GPIOA, &GPIO_InitStruct);

  43.     GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IPU;
  44.     GPIO_InitStruct.GPIO_Pin = GPIO_Pin_12|GPIO_Pin_13|GPIO_Pin_14|GPIO_Pin_15;
  45.     GPIO_InitStruct.GPIO_Speed = GPIO_Speed_2MHz;
  46.     GPIO_Init(GPIOB, &GPIO_InitStruct);
  47. }
  48. /* Configure pins to be interrupts */
  49. void Configure_AButton(void) {
  50.     /* Set variables used */
  51.     GPIO_InitTypeDef GPIO_InitStruct;
  52.     EXTI_InitTypeDef EXTI_InitStruct;
  53.     NVIC_InitTypeDef NVIC_InitStruct;

  55.     /* Enable clock for GPIOA */
  56.     RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

  58.     /* Set pin as input */
  59.     GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IPU;
  60.     GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
  61.     GPIO_InitStruct.GPIO_Speed = GPIO_Speed_2MHz;
  62.     GPIO_Init(GPIOA, &GPIO_InitStruct);

  64.     /* Add IRQ vector to NVIC */
  65.     /* PA0 is connected to EXTI_Line0, which has EXTI0_IRQn vector */
  66.     NVIC_InitStruct.NVIC_IRQChannel = EXTI0_IRQn;
  67.     /* Set priority */
  68.     NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0x00;
  69.     /* Set sub priority */
  70.     NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0x00;
  71.     /* Enable interrupt */
  72.     NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
  73.     /* Add to NVIC */
  74.     NVIC_Init(&NVIC_InitStruct);

  76.     /* Tell system that you will use PA0 for EXTI_Line0 */
  77.     GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0);

  79.     /* PA0 is connected to EXTI_Line0 */
  80.     EXTI_InitStruct.EXTI_Line = EXTI_Line0;
  81.     /* Enable interrupt */
  82.     EXTI_InitStruct.EXTI_LineCmd = ENABLE;
  83.     /* Interrupt mode */
  84.     EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt;
  85.     /* Triggers on rising and falling edge */
  86.     EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Falling;
  87.     /* Add to EXTI */
  88.     EXTI_Init(&EXTI_InitStruct);
  89. }

  91. /* Configure pins to be interrupts */
  92. void Configure_BButton(void) {
  93.     /* Set variables used */
  94.     GPIO_InitTypeDef GPIO_InitStruct;
  95.     EXTI_InitTypeDef EXTI_InitStruct;
  96.     NVIC_InitTypeDef NVIC_InitStruct;

  98.     /* Enable clock for GPIOC */
  99.     RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

  101.     /* Set pin as input */
  102.     GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IPU;
  103.     GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5;
  104.     GPIO_InitStruct.GPIO_Speed = GPIO_Speed_2MHz;
  105.     GPIO_Init(GPIOA, &GPIO_InitStruct);


  108.     NVIC_InitStruct.NVIC_IRQChannel = EXTI9_5_IRQn;
  109.     NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0x00;
  110.     NVIC_InitStruct.NVIC_IRQChannelSubPriority = 0x00;
  111.     NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;
  112.     NVIC_Init(&NVIC_InitStruct);

  114.     GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource5);

  116.     EXTI_InitStruct.EXTI_Line = EXTI_Line5;
  117.     EXTI_InitStruct.EXTI_LineCmd = ENABLE;
  118.     EXTI_InitStruct.EXTI_Mode = EXTI_Mode_Interrupt;
  119.     EXTI_InitStruct.EXTI_Trigger = EXTI_Trigger_Falling;
  120.     EXTI_Init(&EXTI_InitStruct);

  122. }

  124. int main(void)
  125. {
  126.   //Holds the structure for the GPIO pin initialization:
  127.   GPIO_InitTypeDef GPIO_InitStructure;  

  129.   uint16_t bitwise_time=0;    //for value from the DIP switches.
  130.   uint16_t portA_vals;
  131.   uint16_t portB_vals;
  132.   uint16_t iden16=1;


  135.     //Configure_AButton();
  136.     //Configure_BButton();
  137.     Configure_DIP();


  140. //init game settings
  141.     portA_vals=~GPIO_ReadInputData(GPIOA);
  142.     portB_vals=~GPIO_ReadInputData(GPIOB);
  143.     //bit operations
  144.     if(portA_vals&iden16<<10){
  145.         bitwise_time=bitwise_time|1<<0;}
  146.     if(portA_vals&iden16<<9){
  147.         bitwise_time=bitwise_time|1<<1;}
  148.     if(portA_vals&iden16<<8){
  149.         bitwise_time=bitwise_time|1<<2;}
  150.     if(portB_vals&iden16<<15){
  151.         bitwise_time=bitwise_time|1<<3;}
  152.     if(portB_vals&iden16<<14){
  153.         bitwise_time=bitwise_time|1<<4;}
  154.     if(portB_vals&iden16<<13){
  155.         bitwise_time=bitwise_time|1<<5;}
  156.     if(portB_vals&iden16<<12){
  157.         bitwise_time=bitwise_time|1<<6;}
  158. //set that as teams times
  159.     if(bitwise_time==0){
  160.         InitialTime=30;
  161.     }else if(bitwise_time==127){
  162.         InitialTime=99*60;
  163.     }else{
  164.         InitialTime=bitwise_time*60;
  165.     }
  166.     TeamATime=InitialTime;
  167.     TeamBTime=InitialTime;

  169.   // Configure SysTick Timer
  170.   /*System timer tick is used to measure time.
  171.     The Cortex-M3 core used in the STM32 processors has a dedicated timer
  172.     for this function. Its frequency is set as a fraction of the constant
  173.     SystemCoreClock (defined in file system_stm32f10x.c in the
  174.     STM32F10x Standard Peripheral Library directory.)
  175.     We configure it for 1 msec interrupts*/
  176.     if (SysTick_Config(SystemCoreClock/10))  while (1); //If it does not work, stop here for debugging.
  177. //loop
  178.   while (1) {
  179.     asm("nop"); //doing nothing. should put into some energy save mode
  180.   }//End while(1)

  182. } //END main()


  185. // Systic interrupt handler
  186. //Every 100 msec, the timer triggers a call to the SysTick_Handler.
  187. void SysTick_Handler (void){
  188.     TimerTicks++;

  190. }

  192. /* Set interrupt handlers */
  193. /* Handle AButton interrupt */
  194. void EXTI0_IRQHandler(void) {
  195.     /* Make sure that interrupt flag is set */
  196.     if (EXTI_GetITStatus(EXTI_Line0) != RESET) {
  197.         /* Do your stuff when PA0 is changed */
  198.         ControlTeam=TEAM_A;
  199.         /* Clear interrupt flag */
  200.         EXTI_ClearITPendingBit(EXTI_Line0);
  201.     }
  202. }

  204. /* Handle BButton interrupt */
  205. void EXTI9_5_IRQHandler(void) {
  206.     /* Make sure that interrupt flag is set */
  207.     if (EXTI_GetITStatus(EXTI_Line5) != RESET) {
  208.         asm("nop");
  209.         if(GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_5)==0){
  210.             ControlTeam=TEAM_B;
  211.         }
  212.         /* Clear interrupt flag */
  213.         EXTI_ClearITPendingBit(EXTI_Line5);
  214.     }
  215. }


  218. #ifdef USE_FULL_ASSERT
  219.   void assert_failed ( uint8_t* file, uint32_t line)
  220.   {
  221.     /* Infinite loop */
  222.     /* Use GDB to find out why we're here */
  223.     while (1);
  224.   }
  225. #endif
复制代码

友情提示: 此问题已得到解决，问题已经关闭,关闭后问题禁止继续编辑，回答。
该问题目前已经被作者或者管理员关闭, 无法添加新回复
6条回答
76r456546
1楼-- · 2019-07-14 23:20
我建议像这样建立连接：
1.png
1k电阻可保护芯片的引脚。
新星之火12138
2楼-- · 2019-07-14 23:56
 精彩回答 2  元偷偷看……
76r456546
3楼-- · 2019-07-15 03:44
不客气。很高兴我的回答对你有所帮助，引脚在启动时通常处于不确定状态，这就是你需要这种保护的原因
gXDhn
4楼-- · 2019-07-15 07:28
在启动时，我认为一些引脚在短时间内“未定义”。你确定不是这种情况，没有保护电阻将它们连接到Gnd是安全的吗？如果你完全确定这一点，我可以改变我的答案
阿兵888824
5楼-- · 2019-07-15 12:55
电阻器并不是完全没影响，但输出短路接地的损坏很少。这些引脚完成了数据表所说的功能，否则无法在它们周围构建产品。任何处于活动状态的引脚都会记录在案，例如，如果使用硬件捆绑引导，则输入串行引导加载程序。但这不太可能涉及所描绘的引脚。
chinaping2018
6楼-- · 2019-07-15 14:51
不错， 接个电阻可以起保护作用

一周热门 更多>