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dac.c
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Wed, May 1, 22:08

dac.c
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/*
* Copyright (C) 2017 EPFL-LSRO (Laboratoire de Systemes Robotiques).
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "dac.h"
#include "../lib/utils.h"
/**
* @brief Setup a DAC with 2 channels.
*/
void dac_Init(void)
{
DAC_InitTypeDef DAC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
// Periph clock enable.
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);
// GPIO configuration.
GPIO_InitStructure.GPIO_Pin = DAC1_Pin|DAC2_Pin;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(DAC_Port, &GPIO_InitStructure);
// DAC channel Configuration.
DAC_InitStructure.DAC_Trigger = DAC_Trigger_None;
DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_LFSRUnmask_Bit0;
DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
DAC_Init(DAC_Channel_1|DAC_Channel_2, &DAC_InitStructure);
// Enable DAC Channel.
DAC_Cmd(DAC_Channel_1, ENABLE);
DAC_Cmd(DAC_Channel_2, ENABLE);
// Enable DMA for DAC Channel.
DAC_DMACmd(DAC_Channel_1|DAC_Channel_2, ENABLE);
// Set initial voltage to zero.
dac_SetVoltage1(0.0f);
dac_SetVoltage2(0.0f);
}
/**
* @brief Set the voltage of the channel 1 of the DAC.
* @param finalVoltage: the new voltage [V], between +-DAC_FINAL_RANGE (+-9V).
*/
void dac_SetVoltage1(float32_t finalVoltage)
{
float32_t dacVoltageRatio = (-finalVoltage / DAC_FINAL_RANGE / 2.0f) + 0.5f;
uint32_t regVal = (uint32_t)(dacVoltageRatio * (float32_t)DAC_MAX);
utils_SaturateU(&regVal, 0, DAC_MAX);
DAC_SetChannel2Data(DAC_Align_12b_R, (uint16_t)regVal);
}
/**
* @brief Set the voltage of the channel 2 of the DAC.
* @param finalVoltage: the new voltage [V], between +-DAC_FINAL_RANGE (+-9V).
*/
void dac_SetVoltage2(float32_t finalVoltage)
{
float32_t dacVoltageRatio = (-finalVoltage / DAC_FINAL_RANGE / 2.0f) + 0.5f;
uint32_t regVal = (uint32_t)(dacVoltageRatio * (float32_t)DAC_MAX);
utils_SaturateU(&regVal, 0, DAC_MAX);
DAC_SetChannel1Data(DAC_Align_12b_R, (uint16_t)regVal);
}
/**
* @brief Get the current output voltage of the channel 1 of the DAC.
* @retval The current voltage of the channel 1 of the DAC [V].
*/
float32_t dac_GetVoltage1(void)
{
uint32_t regVal = DAC_GetDataOutputValue(DAC_Channel_2);
return -((float32_t)regVal / (float32_t)DAC_MAX - 0.5f) * 2.0f * DAC_FINAL_RANGE;
}
/**
* @brief Get the current output voltage of the channel 2 of the DAC.
* @retval The current voltage of the channel 2 of the DAC [V].
*/
float32_t dac_GetVoltage2(void)
{
uint32_t regVal = DAC_GetDataOutputValue(DAC_Channel_1);
return -((float32_t)regVal / (float32_t)DAC_MAX - 0.5f) * 2.0f * DAC_FINAL_RANGE;
}

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