Files
Embedded-Hacking/drivers/0x03_button/0x03_button.c
Kevin Thomas c55465a6aa Fixed drivers
2026-03-23 11:20:32 -04:00

85 lines
2.9 KiB
C

/**
* @file 0x03_button.c
* @brief Button demonstration: debounced press mirrors to LED + UART report
* @author Kevin Thomas
* @date 2025
*
* MIT License
*
* Copyright (c) 2025 Kevin Thomas
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* -----------------------------------------------------------------------------
*
* Demonstrates GPIO input using the button driver (button.h / button.c).
* The onboard LED mirrors the button state and every edge transition is
* reported over UART.
*
* Wiring:
* GPIO15 -> One leg of push button
* GND -> Other leg of push button
* GPIO25 -> Onboard LED (no external wiring needed)
*/
#include <stdio.h>
#include "pico/stdlib.h"
#include "button.h"
#define BUTTON_PIN 15
#define LED_PIN 25
#define DEBOUNCE_MS 20
/**
* @brief Poll button state and report edge transitions over UART
*
* Reads the debounced button state, mirrors it to the LED, and prints
* a message when the state changes from the previous reading.
*
* @param last_state Pointer to the stored previous button state
*/
static void _poll_button(bool *last_state) {
bool pressed = button_is_pressed(BUTTON_PIN);
button_led_set(LED_PIN, pressed);
if (pressed != *last_state) {
printf("Button: %s\r\n", pressed ? "PRESSED" : "RELEASED");
*last_state = pressed;
}
}
/**
* @brief Application entry point for the button debounce demo
*
* Initializes button and LED, then continuously polls button state
* and mirrors it to the LED with UART reporting on edge transitions.
*
* @return int Does not return
*/
int main(void) {
stdio_init_all();
button_init(BUTTON_PIN, DEBOUNCE_MS);
button_led_init(LED_PIN);
printf("Button driver initialized: button=GPIO%d led=GPIO%d\r\n", BUTTON_PIN, LED_PIN);
bool last_state = false;
while (true) {
_poll_button(&last_state);
sleep_ms(10);
}
}