libopencm3/examples/stm32/f1/stm32-h103/button/button.c

77 lines
2.0 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>
*
* 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/f1/rcc.h>
#include <libopencm3/stm32/f1/gpio.h>
#include <libopencm3/stm32/nvic.h>
#include <libopencm3/stm32/exti.h>
u16 exti_line_state;
/* Set STM32 to 72 MHz. */
void clock_setup(void)
{
rcc_clock_setup_in_hse_8mhz_out_72mhz();
}
void gpio_setup(void)
{
/* Enable GPIOC clock. */
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPCEN);
/* Set GPIO12 (in GPIO port C) to 'output push-pull'. */
gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ,
GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);
}
void button_setup(void)
{
/* Enable GPIOA clock. */
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN);
/* Set GPIO0 (in GPIO port A) to 'input open-drain'. */
gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO0);
}
int main(void)
{
int i;
clock_setup();
gpio_setup();
button_setup();
/* Blink the LED (PC12) on the board. */
while (1) {
gpio_toggle(GPIOC, GPIO12);
exti_line_state = GPIOA_IDR;
if ((exti_line_state & (1 << 0)) != 0) {
for (i = 0; i < 800000; i++) /* Wait a bit. */
__asm__("nop");
}
for (i = 0; i < 800000; i++) /* Wait a bit. */
__asm__("nop");
}
return 0;
}