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[stm32f429i-discovery] Added tick blink example.

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Piotr Esden-Tempski
2015-01-14 18:28:00 -08:00
parent 25d924f699
commit 50b3522e7a
3 changed files with 130 additions and 0 deletions
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examples/stm32/f4/stm32f429i-discovery/tick_blink/tick_blink.c Normal file
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/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
* Copyright (C) 2011 Damjan Marion <damjan.marion@gmail.com>
* Copyright (C) 2011 Mark Panajotovic <marko@electrontube.org>
* Copyright (C) 2013 Chuck McManis <cmcmanis@mcmanis.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/>.
*/
/* This version derived from fancy blink */
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/cm3/systick.h>
/* monotonically increasing number of milliseconds from reset
* overflows every 49 days if you're wondering
*/
volatile uint32_t system_millis;
/* Called when systick fires */
void sys_tick_handler(void)
{
system_millis++;
}
/* sleep for delay milliseconds */
static void msleep(uint32_t delay)
{
uint32_t wake = system_millis + delay;
while (wake > system_millis);
}
/* Set up a timer to create 1mS ticks. */
static void systick_setup(void)
{
/* clock rate / 1000 to get 1mS interrupt rate */
systick_set_reload(168000);
systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);
systick_counter_enable();
/* this done last */
systick_interrupt_enable();
}
/* Set STM32 to 168 MHz. */
static void clock_setup(void)
{
rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_168MHZ]);
/* Enable GPIOG clock. */
rcc_periph_clock_enable(RCC_GPIOG);
}
static void gpio_setup(void)
{
/* Set GPIO13-14 (in GPIO port G) to 'output push-pull'. */
gpio_mode_setup(GPIOG, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE,
GPIO13 | GPIO14);
}
int main(void)
{
clock_setup();
gpio_setup();
systick_setup();
/* Set two LEDs for wigwag effect when toggling. */
gpio_set(GPIOG, GPIO13);
/* Blink the LEDs (PG13 and PG14) on the board. */
while (1) {
gpio_toggle(GPIOG, GPIO13 | GPIO14);
msleep(100);
}
return 0;
}