139 lines
3.8 KiB
C
139 lines
3.8 KiB
C
/*
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* Copyright (c) 2008 Swedish Institute of Computer Science
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* * Neither the name of the copyright holders nor the names of
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* \file
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*
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* \brief
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* Functions to control the ADC of the MCU. This is used to read the
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* joystick.
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*
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* \author
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* Mike Vidales mavida404@gmail.com
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*
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*/
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#include "adc.h"
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/**
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* \addtogroup lcd
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* \{
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*/
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static bool adc_initialized;
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static bool adc_conversion_started;
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/*---------------------------------------------------------------------------*/
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/**
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* \brief This function will init the ADC with the following parameters.
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*
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* \param chan Determines the ADC channel to open.
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* \param trig Sets what type of trigger is needed.
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* \param ref Sets the proper reference voltage.
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* \param prescale Sets the prescale to be used against the XTAL choice.
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*
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* \return 0
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*/
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int
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adc_init(adc_chan_t chan, adc_trig_t trig, adc_ref_t ref, adc_ps_t prescale)
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{
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/* Enable ADC module */
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PRR &= ~(1 << PRADC);
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/* Configure */
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ADCSRA = (1<<ADEN)|prescale;
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ADMUX = (uint8_t)ref|(uint8_t)chan;
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ADCSRB = trig;
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adc_initialized = true;
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adc_conversion_started = false;
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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/**
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* \brief This will disable the adc.
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*/
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void
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adc_deinit(void)
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{
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/* Disable ADC */
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ADCSRA &= ~(1<<ADEN);
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PRR |= (1 << PRADC);
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adc_initialized = false;
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adc_conversion_started = false;
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}
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/*---------------------------------------------------------------------------*/
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/**
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* \brief This will start an ADC conversion
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*
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* \return 0
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*/
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int
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adc_conversion_start(void)
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{
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if (adc_initialized == false){
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return EOF;
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}
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adc_conversion_started = true;
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ADCSRA |= (1<<ADSC);
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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/**
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* \brief This will read the ADC result during the ADC conversion and return
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* the raw ADC conversion result.
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*
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* \param adjust This will Left or Right Adjust the ADC conversion result.
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*
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* \return ADC raw 16-byte ADC conversion result.
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*/
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int16_t
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adc_result_get(adc_adj_t adjust)
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{
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if (adc_conversion_started == false){
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return EOF;
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}
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if (ADCSRA & (1<<ADSC)){
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return EOF;
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}
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adc_conversion_started = false;
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ADMUX |= (adjust<<ADLAR);
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return (int16_t)ADC;
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}
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/** \} */
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