/* button.c */ /* binwatch - Tiny binary wristwatch. {{{ * * Copyright (C) 2010 Nicolas Schodet * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Contact : * Web: http://ni.fr.eu.org/ * Email: * }}} */ #include "common.h" #include "modules/utils/utils.h" #include "io.h" #include "button.h" #include "led.h" #include "power.h" /** Delay for the button to be considered debounced. */ #define BUTTON_DEBOUNCE_MS 100 /** Maximum mesured press duration. */ #define BUTTON_PRESS_MAX_MS 11000 void button_init (void) { /* Initialise pin change interrupt. */ GIMSK |= _BV (PCIE); PCMSK = IO_BV (BUTTON_IO); /* Button is shared with leds, no PORT init. */ } uint16_t button_wait (void) { /* Wait until button is pressed. */ GIFR = _BV (PCIF); /* Clear previous interrupt. */ if (IO_GET (BUTTON_IO)) { /* Sleep, the pin change interrupt will wake me up. */ power_sleep (); } /* Remove pull-up to save battery and shut off leds. */ led_no_pull_up (); /* Wait until button is really released. */ uint16_t press_ms = 0; uint8_t debounce_ms = 0; while (debounce_ms < BUTTON_DEBOUNCE_MS) { power_delay_ms (1); if (IO_GET (BUTTON_IO)) debounce_ms++; else { debounce_ms = 0; if (press_ms < BUTTON_PRESS_MAX_MS) press_ms++; /* If press is really long, go to sleep and wait for interrupt. */ if (press_ms == BUTTON_PRESS_MAX_MS) { GIFR = _BV (PCIF); /* Clear previous interrupt. */ if (!IO_GET (BUTTON_IO)) power_sleep (); } } } return press_ms; } SIGNAL (PCINT0_vect) { /* Nothing to do, only wake up. */ }