Files
libopencm3-examples/examples/stm32/f3/stm32f3-discovery/button/button.c
2014-02-13 19:14:59 +01:00

79 lines
2.1 KiB
C

/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>,
* Copyright (C) 2010 Piotr Esden-Tempski <piotr@esden.net>
* Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
* Modified by Fernando Cortes <fermando.corcam@gmail.com>
* modified by Guillermo Rivera <memogrg@gmail.com>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
uint16_t exti_line_state;
/* Set STM32 to 64 MHz. */
static void clock_setup(void)
{
rcc_clock_setup_hsi(&hsi_8mhz[CLOCK_64MHZ]);
}
static void gpio_setup(void)
{
/* Enable GPIOD clock. */
rcc_periph_clock_enable(RCC_GPIOE);
/* Set GPIO12 (in GPIO port D) to 'output push-pull'. */
gpio_mode_setup(GPIOE, GPIO_MODE_OUTPUT,
GPIO_PUPD_NONE, GPIO8 | GPIO9 | GPIO10 | GPIO11);
}
static void button_setup(void)
{
/* Enable GPIOA clock. */
rcc_periph_clock_enable(RCC_GPIOA);
/* Set GPIO0 (in GPIO port A) to 'input open-drain'. */
gpio_mode_setup(GPIOA, GPIO_MODE_INPUT, GPIO_PUPD_NONE, GPIO0);
}
int main(void)
{
int i;
clock_setup();
button_setup();
gpio_setup();
/* Blink the LED (PD12) on the board. */
while (1) {
gpio_toggle(GPIOE, GPIO11);
/* Upon button press, blink more slowly. */
exti_line_state = GPIOA_IDR;
if ((exti_line_state & (1 << 0)) != 0) {
for (i = 0; i < 3000000; i++) /* Wait a bit. */
__asm__("nop");
}
for (i = 0; i < 1000000; i++) /* Wait a bit. */
__asm__("nop");
}
return 0;
}