A lightweight and efficient push-button driver written in C for STM32 (HAL-based).

Unlike simple polling implementations, this library uses a non-blocking, timer-driven approach, allowing the CPU to continue other tasks.
It can run on any GPIO pins and supports multiple buttons (up to 31) simultaneously.

The library is designed for:

• Projects where CPU blocking must be avoided
• Applications that require short and long press detection
• Easy portability across STM32 families

• 🔹 Multi-button support (PB_CONFIG_COUNT)
• 🔹 Short and long press detection (PB_SHORT_TIME_MS, PB_LONG_TIME_MS)
• 🔹 Event queue with configurable size (PB_EVN_QUEUE_SIZE)
• 🔹 Optional callback on button events
• 🔹 Debouncing for all bottons
• 🔹 Non-blocking operation via timer interrupts
• 🔹 Fully STM32 HAL compatible
• 🔹 Lightweight and modular design

You can install in two ways:

Add these files to your STM32 project:

• pb.h
• pb.c
• pb_config.h

Available in the official pack repo:
👉 STM32-PACK (Not Ready)

Defines library parameters and timing values.

1. GPIO Pins

   • Configure button pins as Input with Pull-Up (active-low buttons recommended).

2. Timer

   • Use internal clock source.
   • Set prescaler to get 1us tick. e.g. for 48Mhz bus, select 48-1.
   • Enable Timer NVIC interrupt.
   • In Project Manager → Code Generator, enable Generate Peripheral initialization as a pair ".c/.h" files per peripheral.
   • In Project Manager → Advanced Settings, enable Register Callback for the timer.

#include "pb.h"

int main(void)
{
    pb_evn_t pb_evn;

    pb_init(NULL); // Initialize without callback

    while (1)
    {
        pb_evn = pb_loop(); // Get next event from queue
        if (pb_evn)
        {
            // 0x00000001 for short press, first key
            // 0x00000002 for short press, second key
            // 0x00000004 for short press, third key
            // Handle button event manually
        }
    }
}

void my_pb_callback(bool is_long, pb_evn_t key_mask)
{
    if (is_long)
    {
        // Handle long press event
    }
    else
    {
        // Handle short press event
    }
}

int main(void)
{
    pb_init(my_pb_callback); // Initialize with callback

    while (1)
    {
        pb_loop();
    }
}

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Licensed under the terms in the LICENSE.