kopia lustrzana https://github.com/OpenRTX/OpenRTX
132 wiersze
4.8 KiB
C
132 wiersze
4.8 KiB
C
/***************************************************************************
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* Copyright (C) 2020 by Silvano Seva IU2KWO 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 <interfaces/gpio.h>
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#include <hwconfig.h>
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#include <stdlib.h>
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#include "ADC1_MDx.h"
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/*
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* The sample buffer is structured as follows:
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*
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* | vbat | rssi | vox | vol |
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*
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* NOTE: we are forced to allocate it through a malloc in order to make it be
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* in the "large" 128kB RAM. This because the linker script maps the .data and
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* .bss sections in the "small" 64kB CCM RAM, which cannot be reached by the DMA.
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*/
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uint16_t *sampleBuf = NULL;
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void adc1_init()
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{
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RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
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RCC->AHB1ENR |= RCC_AHB1ENR_DMA2EN;
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__DSB();
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sampleBuf = ((uint16_t *) malloc(4 * sizeof(uint16_t)));
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/*
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* Configure GPIOs to analog input mode:
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* - PA0: volume potentiometer level
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* - PA1: battery voltage
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* - PA3: vox level
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* - PB0: RSSI level
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*/
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gpio_setMode(AIN_VBAT, INPUT_ANALOG);
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#if defined(PLATFORM_MD3x0)
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gpio_setMode(AIN_VOLUME, INPUT_ANALOG);
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gpio_setMode(AIN_MIC, INPUT_ANALOG);
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gpio_setMode(AIN_RSSI, INPUT_ANALOG);
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#endif
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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 480 ADC cycles and we have to
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* scan four channels: given that a conversion takes 12 cycles, we have a
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* total conversion time of ~187us.
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*/
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ADC->CCR |= ADC_CCR_ADCPRE;
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ADC1->SMPR2 = ADC_SMPR2_SMP0
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| ADC_SMPR2_SMP1
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| ADC_SMPR2_SMP3
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| ADC_SMPR2_SMP8;
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/*
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* No overrun interrupt, 12-bit resolution, no analog watchdog, no
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* discontinuous mode, enable scan mode, no end of conversion interrupts,
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* enable continuous conversion (free-running).
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*/
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ADC1->CR1 |= ADC_CR1_SCAN;
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ADC1->CR2 |= ADC_CR2_DMA
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| ADC_CR2_DDS
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| ADC_CR2_CONT
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| ADC_CR2_ADON;
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/* Scan sequence config. */
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#if defined(PLATFORM_MD3x0)
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ADC1->SQR1 = 3 << 20; /* Four channels to be converted */
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ADC1->SQR3 |= (1 << 0) /* CH1, battery voltage on PA1 */
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| (8 << 5) /* CH8, RSSI value on PB0 */
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| (3 << 10) /* CH3, vox level on PA3 */
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| (0 << 15); /* CH0, volume potentiometer level on PA0 */
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#else
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ADC1->SQR1 = 0; /* Convert one channel */
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ADC1->SQR3 |= (1 << 0); /* CH1, battery voltage on PA1 */
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#endif
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/* DMA2 Stream 0 configuration:
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* - channel 0: ADC1
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* - low priority
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* - half-word transfer, both memory and peripheral
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* - increment memory
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* - circular mode
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* - peripheral-to-memory transfer
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* - no interrupts
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*/
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DMA2_Stream0->PAR = ((uint32_t) &(ADC1->DR));
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DMA2_Stream0->M0AR = ((uint32_t) sampleBuf);
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DMA2_Stream0->NDTR = 4;
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DMA2_Stream0->CR = DMA_SxCR_MSIZE_0 /* Memory size: 16 bit */
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| DMA_SxCR_PSIZE_0 /* Peripheral size: 16 bit */
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| DMA_SxCR_PL_0 /* Medium priority */
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| DMA_SxCR_MINC /* Increment memory */
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| DMA_SxCR_CIRC /* Circular mode */
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| DMA_SxCR_EN;
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/* Finally, start conversion */
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ADC1->CR2 |= ADC_CR2_SWSTART;
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}
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void adc1_terminate()
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{
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free(sampleBuf);
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sampleBuf = NULL;
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DMA2_Stream0->CR &= ~DMA_SxCR_EN;
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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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float adc1_getMeasurement(uint8_t ch)
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{
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if((ch > 3) || (sampleBuf == NULL)) return 0.0f;
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float value = ((float) sampleBuf[ch]);
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return (value * 3300.0f)/4096.0f;
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}
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