/* * This file is part of the libopencm3 project. * * Copyright (C) 2012 Piotr Esden-Tempski * * 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 static void clock_setup(void) { /* Set STM32 to 64 MHz. */ rcc_clock_setup_in_hsi_out_64mhz(); /* Enable alternate function peripheral clock. */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN); /* Enable GPIOB clock. */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN); } static void gpio_setup(void) { /* Configure PB4 as GPIO. */ AFIO_MAPR |= AFIO_MAPR_SWJ_CFG_FULL_SWJ_NO_JNTRST; /* Set GPIO4 and 5 (in GPIO port B) to 'output push-pull'. */ gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO4 | GPIO5); } int main(void) { int i; clock_setup(); gpio_setup(); /* Blink the LEDs on the board. */ while (1) { gpio_toggle(GPIOB, GPIO4); /* LED on/off */ for (i = 0; i < 8000000; i++) /* Wait a bit. */ __asm__("nop"); gpio_toggle(GPIOB, GPIO5); /* LED on/off */ for (i = 0; i < 8000000; i++) /* Wait a bit. */ __asm__("nop"); } return 0; }