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