110 lines
3.3 KiB
C
Executable File
110 lines
3.3 KiB
C
Executable File
/******************************************************************************
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* The MIT License
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*
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* Copyright (c) 2010 Perry Hung.
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* Copyright (c) 2011, 2012 LeafLabs, LLC.
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy,
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* modify, merge, publish, distribute, sublicense, and/or sell copies
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* of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*****************************************************************************/
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/**
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* @file libmaple/adc.c
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* @author Marti Bolivar <mbolivar@leaflabs.com>,
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* Perry Hung <perry@leaflabs.com>
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* @brief Analog to digital converter routines
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*/
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#include <libmaple/adc.h>
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#include <libmaple/libmaple.h>
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#include <libmaple/rcc.h>
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/**
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* @brief Initialize an ADC peripheral.
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*
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* Initializes the RCC clock line for the given peripheral. Resets
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* ADC device registers.
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*
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* @param dev ADC peripheral to initialize
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*/
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void adc_init(adc_dev *dev) {
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rcc_clk_enable(dev->clk_id);
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rcc_reset_dev(dev->clk_id);
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}
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/**
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* @brief Set external event select for regular group
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* @param dev ADC device
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* @param event Event used to trigger the start of conversion.
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* @see adc_extsel_event
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*/
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void adc_set_extsel(adc_dev *dev, adc_extsel_event event) {
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uint32 cr2 = dev->regs->CR2;
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cr2 &= ~ADC_CR2_EXTSEL;
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cr2 |= event;
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dev->regs->CR2 = cr2;
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}
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/**
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* @brief Set the sample rate for all channels on an ADC device.
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*
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* Don't call this during conversion.
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*
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* @param dev adc device
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* @param smp_rate sample rate to set
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* @see adc_smp_rate
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*/
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void adc_set_sample_rate(adc_dev *dev, adc_smp_rate smp_rate) {
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uint32 adc_smpr1_val = 0, adc_smpr2_val = 0;
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int i;
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for (i = 0; i < 10; i++) {
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if (i < 8) {
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/* ADC_SMPR1 determines sample time for channels [10,17] */
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adc_smpr1_val |= smp_rate << (i * 3);
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}
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/* ADC_SMPR2 determines sample time for channels [0,9] */
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adc_smpr2_val |= smp_rate << (i * 3);
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}
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dev->regs->SMPR1 = adc_smpr1_val;
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dev->regs->SMPR2 = adc_smpr2_val;
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}
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/**
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* @brief Perform a single synchronous software triggered conversion on a
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* channel.
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* @param dev ADC device to use for reading.
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* @param channel channel to convert
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* @return conversion result
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*/
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uint16 adc_read(adc_dev *dev, uint8 channel) {
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adc_reg_map *regs = dev->regs;
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adc_set_reg_seqlen(dev, 1);
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regs->SQR3 = channel;
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regs->CR2 |= ADC_CR2_SWSTART;
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while (!(regs->SR & ADC_SR_EOC))
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;
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return (uint16)(regs->DR & ADC_DR_DATA);
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}
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