adc.c

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/** @addtogroup adc_file ADC peripheral API
@ingroup peripheral_apis
 
@author @htmlonly &copy; @endhtmlonly 2014 Karl Palsson <karlp@tweak.net.au>
 
 
LGPL License Terms @ref lgpl_license
 */
/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2014 Karl Palsson <karlp@tweak.net.au>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#include <libopencm3/stm32/adc.h>
 
/**@{*/
 
/*----------------------------------------------------------------------------*/
 
/** @brief ADC Set the Sample Time for a Single Channel
 
The sampling time can be selected in ADC clock cycles from 4 to 384.
 
@param[in] adc Unsigned int32. ADC block base address @ref adc_reg_base.
@param[in] channel uint8. ADC Channel integer 0..18 or from @ref adc_channel.
@param[in] time Unsigned int8. Sampling time selection from @ref adc_sample_rg.
 */
void adc_set_sample_time(uint32_t adc, uint8_t channel, uint8_t time)
{
        uint32_t reg32;
 
        if (channel < 10) {
                reg32 = ADC_SMPR3(adc);
                reg32 &= ~(0x7 << (channel * 3));
                reg32 |= (time << (channel * 3));
                ADC_SMPR3(adc) = reg32;
        } else if (channel < 20) {
                reg32 = ADC_SMPR2(adc);
                reg32 &= ~(0x7 << ((channel - 10) * 3));
                reg32 |= (time << ((channel - 10) * 3));
                ADC_SMPR2(adc) = reg32;
        } else {
                reg32 = ADC_SMPR1(adc);
                reg32 &= ~(0x7 << ((channel - 20) * 3));
                reg32 |= (time << ((channel - 20) * 3));
                ADC_SMPR1(adc) = reg32;
        }
}
 
/*----------------------------------------------------------------------------*/
/** @brief ADC Set the Sample Time for All Channels
 
The sampling time can be selected in ADC clock cycles, same for
all channels.
 
@param[in] adc Unsigned int32. ADC block base address @ref adc_reg_base.
@param[in] time Unsigned int8. Sampling time selection from @ref adc_sample_rg.
*/
 
void adc_set_sample_time_on_all_channels(uint32_t adc, uint8_t time)
{
        uint8_t i;
        uint32_t reg32 = 0;
 
        for (i = 0; i <= 9; i++) {
                reg32 |= (time << (i * 3));
        }
        ADC_SMPR0(adc) = reg32;
        ADC_SMPR1(adc) = reg32;
        ADC_SMPR2(adc) = reg32;
        ADC_SMPR3(adc) = reg32;
}
 
/**@}*/