be1d296e2f
115200 is a much more sane "default" than 38400. Instead of a mix of 38400 and 115200, just use 115200 in all places. There's no reason for modern 32bit cpus to be using such old slow baudrates. Tested on f1, f4, l1. Replaced some old f1 code that predated some library support code for this.
116 lines
3.2 KiB
C
116 lines
3.2 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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* Copyright (C) 2013 Piotr Esden-Tempski <piotr@esden.net>
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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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#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 <libopencm3/cm3/nvic.h>
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static void clock_setup(void)
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{
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/* Enable GPIOD clock for LED & USARTs. */
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rcc_periph_clock_enable(RCC_GPIOD);
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rcc_periph_clock_enable(RCC_GPIOA);
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/* Enable clocks for USART2. */
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rcc_periph_clock_enable(RCC_USART2);
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}
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static void usart_setup(void)
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{
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/* Enable the USART2 interrupt. */
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nvic_enable_irq(NVIC_USART2_IRQ);
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/* Setup GPIO pins for USART2 transmit. */
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gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO2);
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/* Setup GPIO pins for USART2 receive. */
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gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO3);
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gpio_set_output_options(GPIOA, GPIO_OTYPE_OD, GPIO_OSPEED_25MHZ, GPIO3);
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/* Setup USART2 TX and RX pin as alternate function. */
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gpio_set_af(GPIOA, GPIO_AF7, GPIO2);
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gpio_set_af(GPIOA, GPIO_AF7, GPIO3);
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/* Setup USART2 parameters. */
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usart_set_baudrate(USART2, 115200);
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usart_set_databits(USART2, 8);
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usart_set_stopbits(USART2, USART_STOPBITS_1);
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usart_set_mode(USART2, USART_MODE_TX_RX);
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usart_set_parity(USART2, USART_PARITY_NONE);
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usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
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/* Enable USART2 Receive interrupt. */
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usart_enable_rx_interrupt(USART2);
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/* Finally enable the USART. */
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usart_enable(USART2);
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}
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static void gpio_setup(void)
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{
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/* Setup GPIO pin GPIO12 on GPIO port D for LED. */
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gpio_mode_setup(GPIOD, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO12);
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}
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int main(void)
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{
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clock_setup();
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gpio_setup();
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usart_setup();
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while (1) {
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__asm__("NOP");
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}
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return 0;
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}
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void usart2_isr(void)
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{
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static uint8_t data = 'A';
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/* Check if we were called because of RXNE. */
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if (((USART_CR1(USART2) & USART_CR1_RXNEIE) != 0) &&
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((USART_SR(USART2) & USART_SR_RXNE) != 0)) {
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/* Indicate that we got data. */
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gpio_toggle(GPIOD, GPIO12);
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/* Retrieve the data from the peripheral. */
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data = usart_recv(USART2);
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/* Enable transmit interrupt so it sends back the data. */
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usart_enable_tx_interrupt(USART2);
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}
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/* Check if we were called because of TXE. */
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if (((USART_CR1(USART2) & USART_CR1_TXEIE) != 0) &&
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((USART_SR(USART2) & USART_SR_TXE) != 0)) {
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/* Put data into the transmit register. */
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usart_send(USART2, data);
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/* Disable the TXE interrupt as we don't need it anymore. */
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usart_disable_tx_interrupt(USART2);
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}
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}
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