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/******************************************************************************
* The MIT License
*
* Copyright (c) 2010 Perry Hung.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*****************************************************************************/
/**
* @file adc.h
*
* @brief Analog-to-Digital Conversion (ADC) routines.
*/
#ifndef _ADC_H_
#define _ADC_H_
#include "util.h"
#ifdef __cplusplus
extern "C"{
#endif
/* Notes:
* The maximum input impedance on each channel MUST be below .4kohms,
* or face the wrath of incorrect readings...
* This can be changed at the expense of sample time... see datasheet
*
* Need to up the sample time if otherwise... see datasheet */
/* TODO: We'll only use ADC1 for now. See page 41 of the manual for
ADC2 and ADC3's real addresses. */
#define ADC1_BASE 0x40012400
#define ADC2_BASE 0x40012400
#define ADC3_BASE 0x40012400
#define ADC_SR *(volatile uint32*)(ADC1_BASE + 0)
#define ADC_CR1 *(volatile uint32*)(ADC1_BASE + 0x4)
#define ADC_CR2 *(volatile uint32*)(ADC1_BASE + 0x8)
#define ADC_SMPR1 *(volatile uint32*)(ADC1_BASE + 0xC)
#define ADC_SMPR2 *(volatile uint32*)(ADC1_BASE + 0x10)
#define ADC_SQR1 *(volatile uint32*)(ADC1_BASE + 0x2C)
#define ADC_SQR3 *(volatile uint32*)(ADC1_BASE + 0x34)
#define ADC_DR *(volatile uint32*)(ADC1_BASE + 0x4C)
#define CR2_EXTSEL_SWSTART (0xE << 16)
#define CR2_RSTCAL (BIT(3))
#define CR2_EXTTRIG (BIT(20))
/* Bit banded bits */
#define CR2_ADON_BIT *(volatile uint32*)(BITBAND_PERI(ADC1_BASE+0x8, 0))
#define CR2_CAL_BIT *(volatile uint32*)(BITBAND_PERI(ADC1_BASE+0x8, 2))
#define CR2_RSTCAL_BIT *(volatile uint32*)(BITBAND_PERI(ADC1_BASE+0x8, 3))
#define CR2_SWSTART_BIT *(volatile uint32*)(BITBAND_PERI(ADC1_BASE+0x8 + 2, 6))
#define SR_EOC_BIT *(volatile uint32*)(BITBAND_PERI(ADC1_BASE+0, 1))
/* (NR_ANALOG_PINS is board specific) */
/* Initialize ADC1 to do one-shot conversions */
void adc_init(void);
void adc_disable(void);
/* Perform a single conversion on ADC[0-15],
* PRECONDITIONS:
* adc initialized */
static inline int adc_read(int channel) {
/* Set channel */
ADC_SQR3 = channel;
/* Start the conversion */
CR2_SWSTART_BIT = 1;
/* Wait for it to finish */
while(SR_EOC_BIT == 0)
;
return ADC_DR;
}
#ifdef __cplusplus
} // extern "C"
#endif
#endif
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