/* * This file is part of the libopencm3 project. * * Copyright (C) 2009 Uwe Hermann * * 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 void gpio_setup(void) { /* Enable GPIOC clock. */ /* Manually: */ // RCC_APB2ENR |= RCC_APB2ENR_IOPCEN; /* Using API functions: */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPCEN); /* Set GPIO12 (in GPIO port C) to 'output push-pull'. */ /* Manually: */ // GPIOC_CRH = (GPIO_CNF_OUTPUT_PUSHPULL << (((12 - 8) * 4) + 2)); // GPIOC_CRH |= (GPIO_MODE_OUTPUT_2_MHZ << ((12 - 8) * 4)); /* Using API functions: */ gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO12); } int main(void) { int i; gpio_setup(); /* Blink the LED (PC12) on the board. */ while (1) { /* Manually: */ // GPIOC_BSRR = GPIO12; /* LED off */ // for (i = 0; i < 800000; i++) /* Wait a bit. */ // __asm__("nop"); // GPIOC_BRR = GPIO12; /* LED on */ // for (i = 0; i < 800000; i++) /* Wait a bit. */ // __asm__("nop"); /* Using API functions gpio_set()/gpio_clear(): */ // gpio_set(GPIOC, GPIO12); /* LED off */ // for (i = 0; i < 800000; i++) /* Wait a bit. */ // __asm__("nop"); // gpio_clear(GPIOC, GPIO12); /* LED on */ // for (i = 0; i < 800000; i++) /* Wait a bit. */ // __asm__("nop"); /* Using API function gpio_toggle(): */ gpio_toggle(GPIOC, GPIO12); /* LED on/off */ for (i = 0; i < 800000; i++) /* Wait a bit. */ __asm__("nop"); } return 0; }