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/* *****************************************************************************
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Created: 12/18/09 02:35:10
* Copyright (c) 2009 Perry L. Hung. All rights reserved.
*
* ****************************************************************************/
/**
* @file adc.h
*
* @brief ADC prototypes and defines
*/
#ifndef _ADC_H_
#define _ADC_H_
#include <inttypes.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 */
/* We'll only use ADC1 for now... */
#define ADC_BASE 0x40012400
#define ADC_SR *(volatile uint32_t*)(ADC_BASE + 0)
#define ADC_CR1 *(volatile uint32_t*)(ADC_BASE + 0x4)
#define ADC_CR2 *(volatile uint32_t*)(ADC_BASE + 0x8)
#define ADC_SMPR1 *(volatile uint32_t*)(ADC_BASE + 0xC)
#define ADC_SMPR2 *(volatile uint32_t*)(ADC_BASE + 0x10)
#define ADC_SQR1 *(volatile uint32_t*)(ADC_BASE + 0x2C)
#define ADC_SQR3 *(volatile uint32_t*)(ADC_BASE + 0x34)
#define ADC_DR *(volatile uint32_t*)(ADC_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_t*)(BITBAND_PERI(ADC_BASE+0x8, 0))
#define CR2_CAL_BIT *(volatile uint32_t*)(BITBAND_PERI(ADC_BASE+0x8, 2))
#define CR2_RSTCAL_BIT *(volatile uint32_t*)(BITBAND_PERI(ADC_BASE+0x8, 3))
#define CR2_SWSTART_BIT *(volatile uint32_t*)(BITBAND_PERI(ADC_BASE+0x8 + 2, 6))
#define SR_EOC_BIT *(volatile uint32_t*)(BITBAND_PERI(ADC_BASE+0, 1))
#define NR_ANALOG_PINS 16
/* Initialize ADC1 to do one-shot conversions */
void adc_init(void);
void adc_disable(void);
/* Perform a single conversion on ADC[0-16],
* 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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