Overview

Simple de-bounce library for STM32Cube HAL. Tested with NUCLEO-F303K8 and STM32CubeIDE 1.7.0.

Demo Run

• Connect switch to the left side of nucleo as follows:

     [PA9]
     [PA10]
     [NRST]
 +-- [GND]
SW   [PA12]
 +-- [PB0]
     [PB7]
     [PB6]
     [PB1]
     [PF0]
     [PF1]
     [PA8]
 +-- [PA11]
SW   [PB5]
 +-- [PB4]

Run program, push PB0 and/or PA11 button. Built-in LED will lit as follows:

• [PA11] only ... 1 time
• [PB0] only ... 2 times
• [PB11] and [PB0] ... 3 times

Using terminal software through USB connecter, can see more information.

How to use .h/.c

• Define the numbers of button in PushButtons.c
• Call Button_Init() before main loop to define PORT and PIN.
• Buttons must be connected ground, and GPIO has to be set to Pull-Up Digital Input.
• Call uint32_t Button_Loop() to get the return code. If 0, no key detected.

Return code structure in this sample:

bit31 bit30 ... bit2 bit1 bit0
  0     0        0   PB0  PA11

If bit1==1, PB0 was pushed. If bit0==1, PA11 was pushed.

Please notice that the logic is inversed as actual DC level.

• Arrange #define BUTTON_TIME 75 // in msec in PushButtons.c according to switch feeling. This decides de-bounce and release time loughly.

Limitation

This sample can't understand:

• Repeat
• Rolling:push [A], long time after, push [B]
• Double Click: may be recognize as 2 times seperately

Only for "On-Trigger."

And HAL_GetTick() overflow is not understand.