/* * This file is part of the libopencm3 project. * * Copyright (C) 2009 Uwe Hermann * Copyright (C) 2011 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 /* Set STM32 to 72 MHz. */ void clock_setup(void) { rcc_clock_setup_in_hse_12mhz_out_72mhz(); /* Enable GPIOB, GPIOC, and AFIO clocks. */ rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPBEN); rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPCEN); rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_AFIOEN); } void gpio_setup(void) { /* Set GPIO13 (in GPIO port C) to 'output push-pull'. */ gpio_set_mode(GPIOC, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO13); /* Set GPIO4 (in GPIO port B) to 'output push-pull'. */ gpio_set_mode(GPIOB, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO4); AFIO_MAPR |= AFIO_MAPR_SWJ_CFG_FULL_SWJ_NO_JNTRST; /* Preconfigure the LEDs. */ gpio_set(GPIOB, GPIO4); /* Switch off LED. */ gpio_clear(GPIOC, GPIO13); /* Switch on LED. */ } int main(void) { int i; clock_setup(); gpio_setup(); /* Blink the LEDs (PC13 and PB4) on the board. */ while (1) { gpio_toggle(GPIOC, GPIO13); /* LED on/off */ gpio_toggle(GPIOB, GPIO4); /* LED on/off */ for (i = 0; i < 800000; i++) /* Wait a bit. */ __asm__("nop"); } return 0; }