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.
121 lines
3.2 KiB
C
121 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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*
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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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#include <libopencm3/cm3/scb.h>
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static void clock_setup(void)
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{
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rcc_clock_setup_in_hse_8mhz_out_72mhz();
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/* Enable GPIOA clock. */
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rcc_periph_clock_enable(RCC_GPIOA);
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/* Enable clocks for GPIO port A (for LED GPIO_USART2_TX) and 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 pin GPIO_USART2_RE_TX on GPIO port A for transmit. */
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gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
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GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX);
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/* Setup GPIO pin GPIO_USART2_RE_RX on GPIO port A for receive. */
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gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
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GPIO_CNF_INPUT_FLOAT, GPIO_USART2_RX);
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/* Setup UART 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_parity(USART2, USART_PARITY_NONE);
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usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
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usart_set_mode(USART2, USART_MODE_TX_RX);
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/* Enable USART2 Receive interrupt. */
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USART_CR1(USART2) |= USART_CR1_RXNEIE;
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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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gpio_set(GPIOA, GPIO5);
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/* Setup GPIO5 (in GPIO port A) for LED use. */
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gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
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GPIO_CNF_OUTPUT_PUSHPULL, GPIO5);
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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(GPIOA, GPIO5);
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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_CR1(USART2) |= USART_CR1_TXEIE;
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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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/* Indicate that we are sending out data. */
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// gpio_toggle(GPIOA, GPIO5);
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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_CR1(USART2) &= ~USART_CR1_TXEIE;
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}
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}
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int main(void)
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{
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SCB_VTOR = (uint32_t) 0x08005000;
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clock_setup();
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gpio_setup();
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usart_setup();
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/* Wait forever and do nothing. */
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while (1)
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__asm__("nop");
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return 0;
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}
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