/* * This file is part of the libopencm3 project. * * Copyright (C) 2009 Uwe Hermann , * Copyright (C) 2010 Piotr Esden-Tempski * Copyright (C) 2011 Stephen Caudle * * 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 . */ #include #include u16 exti_line_state; /* Set STM32 to 168 MHz. */ static void clock_setup(void) { rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_168MHZ]); } static 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); } static 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; }