Add STM32F4 button example

This commit is contained in:
Stephen Caudle 2011-10-31 15:01:25 -04:00 committed by Stephen Caudle
parent 62c105abeb
commit d17e548c6f
4 changed files with 142 additions and 0 deletions

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##
## This file is part of the libopencm3 project.
##
## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
##
## 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 3 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, see <http://www.gnu.org/licenses/>.
##
BINARY = button
include ../../Makefile.include

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------------------------------------------------------------------------------
README
------------------------------------------------------------------------------
This example blinks the green LED on the ST STM32F4DISCOVERY eval board.
When you press the 'USER' button, the blinking is slower.

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/*
* 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>
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include <libopencm3/stm32/f4/rcc.h>
#include <libopencm3/stm32/f4/gpio.h>
u16 exti_line_state;
/* Set STM32 to 168 MHz. */
void clock_setup(void)
{
rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_168MHZ]);
}
void gpio_setup(void)
{
/* Enable GPIOD clock. */
rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPDEN);
/* Set GPIO12 (in GPIO port D) to 'output push-pull'. */
gpio_mode_setup(GPIOD, GPIO_MODE_OUTPUT,
GPIO_PUPD_NONE,
GPIO12 | GPIO13 | GPIO14 | GPIO15);
}
void button_setup(void)
{
/* Enable GPIOA clock. */
rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPAEN);
/* 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(GPIOD, GPIO12);
/* 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 < 3000000; i++) /* Wait a bit. */
__asm__("nop");
}
return 0;
}

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/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
* Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
/* Linker script for ST STM32F4DISCOVERY (STM32F407VG, 1024K flash, 128K RAM). */
/* Define memory regions. */
MEMORY
{
rom (rx) : ORIGIN = 0x08000000, LENGTH = 1024K
ram (rwx) : ORIGIN = 0x20000000, LENGTH = 128K
}
/* Include the common ld script. */
INCLUDE libopencm3_stm32f4.ld