86 lines
2.3 KiB
C
86 lines
2.3 KiB
C
/*
|
|
* This file is part of the libopencm3 project.
|
|
*
|
|
* Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
|
|
*
|
|
* 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/f1/rcc.h>
|
|
#include <libopencm3/stm32/f1/flash.h>
|
|
#include <libopencm3/stm32/f1/gpio.h>
|
|
#include <libopencm3/stm32/timer.h>
|
|
#include <libopencm3/stm32/nvic.h>
|
|
|
|
void gpio_setup(void)
|
|
{
|
|
/* Enable GPIOB clock. */
|
|
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN);
|
|
|
|
/* Set GPIO6/7 (in GPIO port B) to 'output push-pull' for the LEDs. */
|
|
gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ,
|
|
GPIO_CNF_OUTPUT_PUSHPULL, GPIO6);
|
|
gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_2_MHZ,
|
|
GPIO_CNF_OUTPUT_PUSHPULL, GPIO7);
|
|
}
|
|
|
|
void nvic_setup()
|
|
{
|
|
/* without this the timer interrupt routine will never be called */
|
|
nvic_enable_irq(NVIC_TIM2_IRQ);
|
|
nvic_set_priority(NVIC_TIM2_IRQ, 1);
|
|
}
|
|
|
|
void tim2_isr()
|
|
{
|
|
/* LED2 on/off */
|
|
gpio_toggle(GPIOB, GPIO6);
|
|
|
|
/* clear interrrupt flag */
|
|
TIM_SR(TIM2) &= ~TIM_SR_UIF;
|
|
}
|
|
|
|
int main(void)
|
|
{
|
|
rcc_clock_setup_in_hse_16mhz_out_72mhz();
|
|
gpio_setup();
|
|
nvic_setup();
|
|
|
|
gpio_clear(GPIOB, GPIO7); /* LED1 on */
|
|
gpio_set(GPIOB, GPIO6); /* LED2 off */
|
|
|
|
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM2EN);
|
|
|
|
/* the goal is to let the LED2 glow for a second and then be off for a second */
|
|
|
|
/* Set timer start value */
|
|
TIM_CNT(TIM2) = 1;
|
|
|
|
/* Set timer prescaler. 72MHz/1440 => 50000 counts per second */
|
|
TIM_PSC(TIM2) = 1440;
|
|
|
|
/* End timer value. If this value is reached an interrupt is generated */
|
|
TIM_ARR(TIM2) = 50000;
|
|
|
|
/* Update interrupt enable */
|
|
TIM_DIER(TIM2) |= TIM_DIER_UIE;
|
|
|
|
/* Start timer */
|
|
TIM_CR1(TIM2) |= TIM_CR1_CEN;
|
|
|
|
while(1); /* Halt. */
|
|
|
|
return 0;
|
|
}
|