94 lines
2.4 KiB
C
94 lines
2.4 KiB
C
/*
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* This file is part of the libopencm3 project.
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*
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* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>,
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* Copyright (C) 2010 Piotr Esden-Tempski <piotr@esden.net>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <libopencm3/stm32/f1/rcc.h>
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#include <libopencm3/stm32/f1/gpio.h>
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#include <libopencm3/stm32/nvic.h>
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#include <libopencm3/stm32/exti.h>
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#define FALLING 0
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#define RISING 1
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u16 exti_direction = FALLING;
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/* Set STM32 to 72 MHz. */
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void clock_setup(void)
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{
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rcc_clock_setup_in_hse_8mhz_out_72mhz();
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}
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void gpio_setup(void)
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{
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/* Enable GPIOC clock. */
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rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPCEN);
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/* Set GPIO12 (in GPIO port C) to 'output push-pull'. */
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gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ,
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GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);
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}
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void exti_setup(void)
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{
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/* Enable GPIOA clock. */
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rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN);
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/* Enable AFIO clock. */
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rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN);
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/* Enable EXTI0 interrupt. */
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nvic_enable_irq(NVIC_EXTI0_IRQ);
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/* Set GPIO0 (in GPIO port A) to 'input open-drain'. */
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gpio_set_mode(GPIOA, GPIO_MODE_INPUT, GPIO_CNF_INPUT_FLOAT, GPIO0);
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/* Configure the EXTI subsystem. */
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exti_select_source(EXTI0, GPIOA);
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exti_direction = FALLING;
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exti_set_trigger(EXTI0, EXTI_TRIGGER_FALLING);
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exti_enable_request(EXTI0);
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}
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void exti0_isr(void)
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{
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exti_reset_request(EXTI0);
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if (exti_direction == FALLING) {
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gpio_set(GPIOC, GPIO12);
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exti_direction = RISING;
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exti_set_trigger(EXTI0, EXTI_TRIGGER_RISING);
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} else {
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gpio_clear(GPIOC, GPIO12);
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exti_direction = FALLING;
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exti_set_trigger(EXTI0, EXTI_TRIGGER_FALLING);
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}
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}
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int main(void)
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{
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clock_setup();
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gpio_setup();
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exti_setup();
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while (1)
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__asm("nop");
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return 0;
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}
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