122 lines
3.0 KiB
C
122 lines
3.0 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) 2011 Stephen Caudle <scaudle@doceme.com>
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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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#define _GNU_SOURCE
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#include <libopencm3/stm32/rcc.h>
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#include <libopencm3/stm32/gpio.h>
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#include <libopencm3/stm32/usart.h>
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#include <stdio.h>
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#include <errno.h>
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#include <stddef.h>
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#include <sys/types.h>
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static ssize_t _iord(void *_cookie, char *_buf, size_t _n);
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static ssize_t _iowr(void *_cookie, const char *_buf, size_t _n);
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static ssize_t _iord(void *_cookie, char *_buf, size_t _n)
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{
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/* dont support reading now */
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(void)_cookie;
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(void)_buf;
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(void)_n;
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return 0;
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}
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static ssize_t _iowr(void *_cookie, const char *_buf, size_t _n)
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{
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uint32_t dev = (uint32_t)_cookie;
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int written = 0;
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while (_n-- > 0) {
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usart_send_blocking(dev, *_buf++);
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written++;
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};
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return written;
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}
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static FILE *usart_setup(uint32_t dev)
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{
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/* Setup USART parameters. */
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usart_set_baudrate(dev, 115200);
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usart_set_databits(dev, 8);
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usart_set_parity(dev, USART_PARITY_NONE);
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usart_set_stopbits(dev, USART_CR2_STOPBITS_1);
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usart_set_mode(dev, USART_MODE_TX_RX);
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usart_set_flow_control(dev, USART_FLOWCONTROL_NONE);
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/* Finally enable the USART. */
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usart_enable(dev);
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cookie_io_functions_t stub = { _iord, _iowr, NULL, NULL };
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FILE *fp = fopencookie((void *)dev, "rw+", stub);
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/* Do not buffer the serial line */
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setvbuf(fp, NULL, _IONBF, 0);
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return fp;
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}
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static void clock_setup(void)
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{
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/* Enable GPIOC clock for LED & USARTs. */
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rcc_periph_clock_enable(RCC_GPIOC);
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rcc_periph_clock_enable(RCC_GPIOA);
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/* Enable clocks for USART. */
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rcc_periph_clock_enable(RCC_USART1);
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}
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static void gpio_setup(void)
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{
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/* Setup GPIO pin GPIO8/9 on GPIO port C for LEDs. */
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gpio_mode_setup(GPIOC, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO8 | GPIO9);
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/* Setup GPIO pins for USART transmit. */
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gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO9);
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/* Setup USART TX pin as alternate function. */
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gpio_set_af(GPIOA, GPIO_AF1, GPIO9);
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}
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int main(void)
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{
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int i, c = 0;
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FILE *fp;
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clock_setup();
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gpio_setup();
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fp = usart_setup(USART1);
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/* Blink the LED on the board with every transmitted byte. */
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while (1) {
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gpio_toggle(GPIOC, GPIO8); /* LED on/off */
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fprintf(fp, "Pass: %d\n", c);
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c = (c == 200) ? 0 : c + 1; /* Increment c. */
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for (i = 0; i < 1000000; i++) { /* Wait a bit. */
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__asm__("NOP");
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}
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}
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return 0;
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}
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