Open source key component multi_ Button use, including test engineering

In the previous article, I introduced the processing method of keys 《 multi-function （ single click 、 double-click 、 Long press ） Key design 》, Let's share another way today ：MultiButton.

1.Multi_Button brief introduction

MultiButton yes Github An open source key processing component on , author 0x1abin.

GIthub Address ：https://github.com/0x1abin/MultiButton

MultiButton A small and easy-to-use event driven key driver module , Unlimited expansion of keys , The callback asynchronous processing of key events can simplify your program structure , Remove redundant key processing hard coding , Make your key business logic clearer .

Key supported events include ：

2.Multi_Button Use

The module has only two files multi_button.c and multi_button.h, When using , take .c Add files to the project . Here we use STM32 For example .

    2.1. Include header file #include"multi_button.h"

    2.2. Define key structure and key ID, It's defined here 2 A button ：

Button button1;
Button button2;


#define btn1_id  1
#define btn2_id  2

   2.3. Write a read key GPIO As a function of level ：

uint8_t read_button_GPIO(uint8_t button_id)
{
  // you can share the GPIO read function with multiple Buttons
  switch(button_id)
  {
    case btn1_id:
      return HAL_GPIO_ReadPin(KEY0_GPIO_Port, KEY0_Pin);
      break;
    case btn2_id:
      return HAL_GPIO_ReadPin(KEY1_GPIO_Port, KEY1_Pin);
      break;
    default:
      return 0;
      break;
  }
}

    2.4. Initialize the key object ：

button_init(&button1, read_button_GPIO, 0, btn1_id);
button_init(&button2, read_button_GPIO, 0, btn2_id);

     stay button_init Function ：

     The first parameter is zero 2.2 Key structure pointer defined in .

     The second parameter is bound 2.3 Read keys written in GPIO As a function of level .

     The third parameter is the effective level of the key ,0 Indicates that the low level is active ,1 Represents high level active .

     The fourth parameter is the key ID.

    2.5. Bind key callback function ：       

button_attach(&button1, PRESS_DOWN,       BTN_PRESS_DOWN_Handler);
button_attach(&button1, PRESS_UP,         BTN_PRESS_UP_Handler);
button_attach(&button1, PRESS_REPEAT,     BTN_PRESS_REPEAT_Handler);
button_attach(&button1, SINGLE_CLICK,     BTN_SINGLE_Click_Handler);
button_attach(&button1, DOUBLE_CLICK,     BTN_DOUBLE_Click_Handler);
button_attach(&button1, LONG_PRESS_START, BTN_LONG_PRESS_START_Handler);
button_attach(&button1, LONG_PRESS_HOLD,  BTN_LONG_PRESS_HOLD_Handler);
      
button_attach(&button2, PRESS_DOWN,       BTN_PRESS_DOWN_Handler);
button_attach(&button2, PRESS_UP,         BTN_PRESS_UP_Handler);
button_attach(&button2, PRESS_REPEAT,     BTN_PRESS_REPEAT_Handler);
button_attach(&button2, SINGLE_CLICK,     BTN_SINGLE_Click_Handler);
button_attach(&button2, DOUBLE_CLICK,     BTN_DOUBLE_Click_Handler);
button_attach(&button2, LONG_PRESS_START, BTN_LONG_PRESS_START_Handler);
button_attach(&button2, LONG_PRESS_HOLD,  BTN_LONG_PRESS_HOLD_Handler);

All key functions are bound here , Users can delete according to actual needs . Different key callback functions can be the same , Take the callback function of pressing the key as an example , Function as follows ：

void BTN_PRESS_DOWN_Handler(void* btn)
{
       Button *temp_button = (Button *)btn;
       switch(temp_button->button_id)
       {
              case btn1_id:
                     printf("btn1 press down\r\n");
                     break;
              case btn2_id:
                     printf("btn2 press down\r\n");
                     break;
              default:
                     break;
       }
}

    2.6. Call the startup function ：

button_start(&button1);
button_start(&button2);

    2.7. Last , You need to call the key scanning function in a timed task ：

void scan_key()
{
       if(key_tick < TICKS_INTERVAL)return;
       key_tick = 0;
       button_ticks();
}

     It should be noted that , Scan cycle of the key 、 Long press 、 Short press 、 Double click the time definition in .h Modification in file ：

//According to your need to modify the constants.
#define TICKS_INTERVAL    10       //ms
#define DEBOUNCE_TICKS    3       //MAX 8
#define SHORT_TICKS       (300 /TICKS_INTERVAL)
#define LONG_TICKS        (1000 /TICKS_INTERVAL)

     Finally, let's test the effect , Press the key 、 Spring up 、 single click 、 double-click 、 Long press, etc. can be detected , It's very convenient to use .

The source code of this open source key module is only 200 Row or so , Interested friends can do their own research .

Test engineering link ：

link ：https://pan.baidu.com/s/1wiw5Ajoooc7WZFgwO87zqw

Extraction code ：wola

Recommended reading ：

ITM Mechanism - You can... Without serial port printf

multi-function （ single click 、 double-click 、 Long press ） Key design

How to measure the running time of single chip microcomputer program ？

How to check the variable waveform when debugging the program ？ Look here

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