mirror of
https://github.com/eddyem/stm32samples.git
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85 lines
2.5 KiB
C
85 lines
2.5 KiB
C
/*
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* main.c
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*
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* Copyright 2017 Edward V. Emelianoff <eddy@sao.ru, edward.emelianoff@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program 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 General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301, USA.
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*/
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#include "stm32f0.h"
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#include "usart.h"
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volatile uint32_t Tms = 0;
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/* Called when systick fires */
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void sys_tick_handler(void){
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++Tms;
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}
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static void gpio_setup(void){
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/* Enable clocks to the GPIO subsystems (A&B) */
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RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
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/* Set green leds (PA5 & PA4) as output */
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GPIOA->MODER = GPIO_MODER_MODER4_O | GPIO_MODER_MODER5_O;
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GPIOA->OTYPER = 1 << 5; // PA5 - opendrain, PA4 - pushpull
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/* PA6 - switch blink rate (pullup input) */
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GPIOA->PUPDR = GPIO_PUPDR_PUPDR6_0;
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}
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/**
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* reverce line
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*/
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char *rline(char *in, int L){
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static char out[UARTBUFSZ];
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if(L > UARTBUFSZ - 1) return in;
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char *optr = out, *iptr = &in[L-1];
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for(; L > 0; --L) *optr++ = *iptr--;
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*optr = '\n';
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return out;
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}
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int main(void){
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uint32_t lastT = 0;
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int L = 0;
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char *txt;
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sysreset();
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SysTick_Config(6000, 1);
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gpio_setup();
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USART1_config();
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//StartHSE();
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pin_set(GPIOA, 1<<5); // clear extern LED
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/* Do nothing in main loop */
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while (1){
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if(lastT > Tms || Tms - lastT > 499){
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pin_toggle(GPIOA, 1<<4); // blink by onboard LED once per second
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lastT = Tms;
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}
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if(usart1rx()){ // usart1 received data, store in in buffer
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L = usart1_getline(&txt);
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if(!pin_read(GPIOA, 1<<6)){ // there's a jumper: reverse string
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txt = rline(txt, L);
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}
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pin_clear(GPIOA, 1<<5); // set extern LED
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}
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if(L){ // text waits for sending
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if(ALL_OK == usart1_send(txt, L)){
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L = 0;
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pin_set(GPIOA, 1<<5); // clear extern LED
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}
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}
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}
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}
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