kopia lustrzana https://github.com/OpenRTX/OpenRTX
94 wiersze
3.2 KiB
C
94 wiersze
3.2 KiB
C
/***************************************************************************
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* Copyright (C) 2020 - 2023 by Silvano Seva IU2KWO *
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* and Niccolò Izzo IU2KIN *
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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 3 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, see <http://www.gnu.org/licenses/> *
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***************************************************************************/
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#include <peripherals/gpio.h>
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#include <hwconfig.h>
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#include <pthread.h>
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#include <stdlib.h>
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#include "ADC1_Mod17.h"
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static pthread_mutex_t adcMutex;
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void adc1_init()
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{
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pthread_mutex_init(&adcMutex, NULL);
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RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
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__DSB();
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/*
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* Configure GPIOs to analog input mode:
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*/
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gpio_setMode(AIN_HWVER, INPUT_ANALOG);
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/*
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* ADC clock is APB2 frequency divided by 8, giving 10.5MHz.
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* We set the sample time of each channel to 84 ADC cycles and we have that
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* a conversion takes 12 cycles: total conversion time is then of ~9us.
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*/
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ADC->CCR |= ADC_CCR_ADCPRE;
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ADC1->SMPR2 = ADC_SMPR2_SMP3_2;
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/*
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* Convert one channel, no overrun interrupt, 12-bit resolution,
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* no analog watchdog, discontinuous mode, no end of conversion interrupts,
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* turn on ADC.
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*/
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ADC1->SQR1 = 0;
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ADC1->CR2 = ADC_CR2_ADON;
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}
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void adc1_terminate()
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{
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pthread_mutex_destroy(&adcMutex);
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ADC1->CR2 &= ~ADC_CR2_ADON;
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RCC->APB2ENR &= ~RCC_APB2ENR_ADC1EN;
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__DSB();
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}
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uint16_t adc1_getRawSample(uint8_t ch)
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{
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if(ch > 15) return 0;
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pthread_mutex_lock(&adcMutex);
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ADC1->SQR3 = ch;
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ADC1->CR2 |= ADC_CR2_SWSTART;
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while((ADC1->SR & ADC_SR_EOC) == 0) ;
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uint16_t value = ADC1->DR;
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pthread_mutex_unlock(&adcMutex);
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return value;
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}
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uint16_t adc1_getMeasurement(uint8_t ch)
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{
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/*
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* To avoid using floats, we convert the raw ADC sample to mV using 16.16
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* fixed point math. The equation for conversion is (sample * 3300)/4096 but,
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* since converting the raw ADC sample to 16.16 notation requires a left
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* shift by 16 and dividing by 4096 is equivalent to shifting right by 12,
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* we just shift left by four and then multiply by 3300.
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* With respect to using floats, maximum error is -1mV.
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*/
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uint32_t sample = (adc1_getRawSample(ch) << 4) * 3300;
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return ((uint16_t) (sample >> 16));
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}
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