bb8f4699da
Using GPIOA_IDR directly looks a bit arcane, and the example can benefit from introducing gpio_get() and how to use it. The stm32f0-discovery example already does it like this.
76 lines
2.0 KiB
C
76 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>
|
|
* Copyright (C) 2013 Joshua Harlan Lifton <joshua.harlan.lifton@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>
|
|
|
|
/* Set STM32 to 24 MHz. */
|
|
static void clock_setup(void)
|
|
{
|
|
rcc_clock_setup_in_hse_8mhz_out_24mhz();
|
|
}
|
|
|
|
static void gpio_setup(void)
|
|
{
|
|
/* Enable GPIOC clock. */
|
|
rcc_periph_clock_enable(RCC_GPIOC);
|
|
|
|
/* Set GPIO9 (in GPIO port C) to 'output push-pull'. */
|
|
gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ,
|
|
GPIO_CNF_OUTPUT_PUSHPULL, GPIO9);
|
|
}
|
|
|
|
static void button_setup(void)
|
|
{
|
|
/* Enable GPIOA clock. */
|
|
rcc_periph_clock_enable(RCC_GPIOA);
|
|
|
|
/* Set GPIO9 (in GPIO port A) to 'input with pull-up resistor'. */
|
|
gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
|
|
GPIO_CNF_INPUT_PULL_UPDOWN, GPIO9);
|
|
gpio_set(GPIOA, GPIO9);
|
|
}
|
|
|
|
int main(void)
|
|
{
|
|
int i;
|
|
|
|
clock_setup();
|
|
gpio_setup();
|
|
button_setup();
|
|
|
|
/* Blink LED1 (PC9) on the board. */
|
|
while (1) {
|
|
gpio_toggle(GPIOC, GPIO9);
|
|
|
|
/* Upon button press, blink more slowly. */
|
|
if (gpio_get(GPIOA, GPIO9)) {
|
|
for (i = 0; i < 800000; i++) /* Wait a bit. */
|
|
__asm__("nop");
|
|
}
|
|
|
|
for (i = 0; i < 800000; i++) /* Wait a bit. */
|
|
__asm__("nop");
|
|
}
|
|
|
|
return 0;
|
|
}
|