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https://github.com/eddyem/stm32samples.git
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118 lines
3.3 KiB
C
118 lines
3.3 KiB
C
/*
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* timer.c
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*
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* Copyright 2016 Edward V. Emelianov <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 "timer.h"
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#include "user_proto.h" // for print_int
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// current speed
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uint16_t current_RPM = 0;
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void get_RPM();
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uint16_t get_ARR(uint32_t RPM);
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// pulses: 16 1/0, 4 1/1, 16 1/0, 4 0/0,
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const uint8_t pulses[] = {
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1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,
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1,1,1,1,1,1,1,1,
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1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,1,0,
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0,0,0,0,0,0,0,0};
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const int pulsesLen = sizeof(pulses) - 1;
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void tim2_init(){
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// init TIM2
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rcc_periph_clock_enable(RCC_TIM2);
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timer_reset(TIM2);
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// timer have frequency of 1MHz
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timer_set_mode(TIM2, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
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// 72MHz div 36 = 2MHz
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TIM2_PSC = 35; // we need double freq to serve both halfs of signal
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TIM2_ARR = get_ARR(MIN_RPM);
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TIM2_DIER = TIM_DIER_UDE | TIM_DIER_UIE;
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nvic_enable_irq(NVIC_TIM2_IRQ);
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TIM2_CR1 |= TIM_CR1_CEN;
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get_RPM();
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}
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void tim2_isr(){
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static uint16_t ctr = 0;
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if(TIM2_SR & TIM_SR_UIF){ // update interrupt
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if(ctr > pulsesLen) ctr = 0;
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if(pulses[++ctr])
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GPIO_BSRR(OUTP_PORT) = OUTP_PIN;
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else
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GPIO_BSRR(OUTP_PORT) = OUTP_PIN << 16;
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}
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TIM2_SR = 0;
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}
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/**
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* Calculate motor speed in RPM
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* RPM = 1/tim2_arr / 40 * 60
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*/
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void get_RPM(){
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uint32_t R = 3000000 / (uint32_t)TIM2_ARR;
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current_RPM = R/2;
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//current_RPM = R;
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//current_RPM >>= 1; // x/2 != x>>1, WTF?
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}
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// calculate TIM2_ARR by RPM
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uint16_t get_ARR(uint32_t RPM){
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uint32_t R = 3000000 / RPM;
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R /= 2;
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//R >>= 1;
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return (uint16_t)R;
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}
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/**
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* Change "rotation speed" by 100rpm
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*/
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void increase_speed(){
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if(current_RPM == MAX_RPM) return;
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current_RPM += 100;
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if(current_RPM > MAX_RPM){ // set LED "MAX"
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current_RPM = MAX_RPM;
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TIM2_ARR = get_ARR(current_RPM);
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gpio_clear(LEDS_PORT, LED_UPPER_PIN);
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}else{
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TIM2_ARR = get_ARR(current_RPM);
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get_RPM(); // recalculate speed
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gpio_set(LEDS_PORT, LED_UPPER_PIN);
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}
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gpio_set(LEDS_PORT, LED_LOW_PIN);
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print_int(current_RPM);
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}
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void decrease_speed(){
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if(current_RPM == MIN_RPM) return;
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current_RPM -= 100;
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if(current_RPM < MIN_RPM){ // set LED "MIN"
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current_RPM = MIN_RPM;
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TIM2_ARR = get_ARR(current_RPM);
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gpio_clear(LEDS_PORT, LED_LOW_PIN);
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}else{
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TIM2_ARR = get_ARR(current_RPM);
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get_RPM();
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gpio_set(LEDS_PORT, LED_LOW_PIN);
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}
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gpio_set(LEDS_PORT, LED_UPPER_PIN);
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print_int(current_RPM);
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}
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