84 lines
2.5 KiB
C
84 lines
2.5 KiB
C
/*
|
|
* This file is part of the libopencm3 project.
|
|
*
|
|
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
|
|
* Copyright (C) 2011 Stephen Caudle <scaudle@doceme.com>
|
|
*
|
|
* 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 <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <libopencm3/stm32/f4/rcc.h>
|
|
#include <libopencm3/stm32/f4/gpio.h>
|
|
#include <libopencm3/stm32/usart.h>
|
|
|
|
void clock_setup(void)
|
|
{
|
|
/* Enable GPIOD clock for LED & USARTs. */
|
|
rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPDEN);
|
|
rcc_peripheral_enable_clock(&RCC_AHB1ENR, RCC_AHB1ENR_IOPAEN);
|
|
|
|
/* Enable clocks for USART2. */
|
|
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN);
|
|
}
|
|
|
|
void usart_setup(void)
|
|
{
|
|
/* Setup USART2 parameters. */
|
|
usart_set_baudrate(USART2, 38400);
|
|
usart_set_databits(USART2, 8);
|
|
usart_set_stopbits(USART2, USART_STOPBITS_1);
|
|
usart_set_mode(USART2, USART_MODE_TX);
|
|
usart_set_parity(USART2, USART_PARITY_NONE);
|
|
usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
|
|
|
|
/* Finally enable the USART. */
|
|
usart_enable(USART2);
|
|
}
|
|
|
|
void gpio_setup(void)
|
|
{
|
|
/* Setup GPIO pin GPIO12 on GPIO port D for LED. */
|
|
gpio_mode_setup(GPIOD, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO12);
|
|
|
|
/* Setup GPIO pins for USART2 transmit. */
|
|
gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO2);
|
|
|
|
/* Setup USART2 TX pin as alternate function. */
|
|
gpio_set_af(GPIOA, GPIO_AF7, GPIO2);
|
|
}
|
|
|
|
int main(void)
|
|
{
|
|
int i, j = 0, c = 0;
|
|
|
|
clock_setup();
|
|
gpio_setup();
|
|
usart_setup();
|
|
|
|
/* Blink the LED (PD12) on the board with every transmitted byte. */
|
|
while (1) {
|
|
gpio_toggle(GPIOD, GPIO12); /* LED on/off */
|
|
usart_send_blocking(USART2, c + '0'); /* USART2: Send byte. */
|
|
c = (c == 9) ? 0 : c + 1; /* Increment c. */
|
|
if ((j++ % 80) == 0) { /* Newline after line full. */
|
|
usart_send_blocking(USART2, '\r');
|
|
usart_send_blocking(USART2, '\n');
|
|
}
|
|
for (i = 0; i < 3000000; i++) /* Wait a bit. */
|
|
__asm__("NOP");
|
|
}
|
|
|
|
return 0;
|
|
}
|