mbed-os

Fork of mbed-os by erkin yucel

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

Who changed what in which revision?

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elessair 0:f269e3021894 1 /**
elessair 0:f269e3021894 2 ******************************************************************************
elessair 0:f269e3021894 3 * @file adc_sar.c
elessair 0:f269e3021894 4 * @brief Implementation of a SAR ADC driver
elessair 0:f269e3021894 5 * @internal
elessair 0:f269e3021894 6 * @author ON Semiconductor
elessair 0:f269e3021894 7 * $Rev:
elessair 0:f269e3021894 8 * $Date:
elessair 0:f269e3021894 9 ******************************************************************************
elessair 0:f269e3021894 10 * Copyright 2016 Semiconductor Components Industries LLC (d/b/a “ON Semiconductor”).
elessair 0:f269e3021894 11 * All rights reserved. This software and/or documentation is licensed by ON Semiconductor
elessair 0:f269e3021894 12 * under limited terms and conditions. The terms and conditions pertaining to the software
elessair 0:f269e3021894 13 * and/or documentation are available at http://www.onsemi.com/site/pdf/ONSEMI_T&C.pdf
elessair 0:f269e3021894 14 * (“ON Semiconductor Standard Terms and Conditions of Sale, Section 8 Software”) and
elessair 0:f269e3021894 15 * if applicable the software license agreement. Do not use this software and/or
elessair 0:f269e3021894 16 * documentation unless you have carefully read and you agree to the limited terms and
elessair 0:f269e3021894 17 * conditions. By using this software and/or documentation, you agree to the limited
elessair 0:f269e3021894 18 * terms and conditions.
elessair 0:f269e3021894 19 *
elessair 0:f269e3021894 20 * THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED
elessair 0:f269e3021894 21 * OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
elessair 0:f269e3021894 22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
elessair 0:f269e3021894 23 * ON SEMICONDUCTOR SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL,
elessair 0:f269e3021894 24 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
elessair 0:f269e3021894 25 * @endinternal
elessair 0:f269e3021894 26 *
elessair 0:f269e3021894 27 * @ingroup adc_sar
elessair 0:f269e3021894 28 *
elessair 0:f269e3021894 29 * @details
elessair 0:f269e3021894 30 * <p>
elessair 0:f269e3021894 31 * </p>
elessair 0:f269e3021894 32 *
elessair 0:f269e3021894 33 */
elessair 0:f269e3021894 34
elessair 0:f269e3021894 35 #include "device.h"
elessair 0:f269e3021894 36 #include "analogin_api.h"
elessair 0:f269e3021894 37 #include "PeripheralPins.h"
elessair 0:f269e3021894 38 #include "mbed_assert.h"
elessair 0:f269e3021894 39 #include "clock.h"
elessair 0:f269e3021894 40 #include "adc_sar.h"
elessair 0:f269e3021894 41
elessair 0:f269e3021894 42 #if DEVICE_ANALOGIN
elessair 0:f269e3021894 43
elessair 0:f269e3021894 44 /**
elessair 0:f269e3021894 45 * \defgroup hal_analogin Analogin hal functions
elessair 0:f269e3021894 46 * @{
elessair 0:f269e3021894 47 */
elessair 0:f269e3021894 48
elessair 0:f269e3021894 49 /** Initialize the analogin peripheral
elessair 0:f269e3021894 50 *
elessair 0:f269e3021894 51 * Configures the pin used by analogin.
elessair 0:f269e3021894 52 * @param obj The analogin object to initialize
elessair 0:f269e3021894 53 * @param pin The analogin pin name
elessair 0:f269e3021894 54 */
elessair 0:f269e3021894 55 void analogin_init(analogin_t *obj, PinName pin)
elessair 0:f269e3021894 56 {
elessair 0:f269e3021894 57 CLOCK_ENABLE(CLOCK_ADC);
elessair 0:f269e3021894 58 ADCName adc;
elessair 0:f269e3021894 59 uint8_t adc_pin = 0;
elessair 0:f269e3021894 60
elessair 0:f269e3021894 61 adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
elessair 0:f269e3021894 62 MBED_ASSERT(adc != (ADCName)NC);
elessair 0:f269e3021894 63
elessair 0:f269e3021894 64 obj->adcReg = (AdcReg_pt)adc;
elessair 0:f269e3021894 65 obj->pin = pin;
elessair 0:f269e3021894 66 obj->pinFlag = 1;
elessair 0:f269e3021894 67
elessair 0:f269e3021894 68 switch (pin) {
elessair 0:f269e3021894 69 case A0:
elessair 0:f269e3021894 70 adc_pin=0;
elessair 0:f269e3021894 71 break;
elessair 0:f269e3021894 72 case A1:
elessair 0:f269e3021894 73 adc_pin = 1;
elessair 0:f269e3021894 74 break;
elessair 0:f269e3021894 75 case A2:
elessair 0:f269e3021894 76 adc_pin = 2;
elessair 0:f269e3021894 77 break;
elessair 0:f269e3021894 78 case A3:
elessair 0:f269e3021894 79 adc_pin = 3;
elessair 0:f269e3021894 80 break;
elessair 0:f269e3021894 81 default:
elessair 0:f269e3021894 82 break;
elessair 0:f269e3021894 83 }
elessair 0:f269e3021894 84
elessair 0:f269e3021894 85 /* If no config parameters are passed on; assume default value */
elessair 0:f269e3021894 86 if (obj->adcConf == Null) {
elessair 0:f269e3021894 87 /* Single sample, absolute conversion, scale = 1 */
elessair 0:f269e3021894 88 obj->adcReg->CONTROL.WORD = ((0 << ADC_CONTROL_MODE_BIT_POS) |
elessair 0:f269e3021894 89 (1 << ADC_CONTROL_MEASTYPE_BIT_POS) |
elessair 0:f269e3021894 90 (1 << ADC_CONTROL_INPUTSCALE_BIT_POS) |
elessair 0:f269e3021894 91 (((uint8_t)adc_pin) << ADC_CONTROL_MEAS_CH_BIT_POS));
elessair 0:f269e3021894 92
elessair 0:f269e3021894 93 /* Prescaler enabled; set to 7 */
elessair 0:f269e3021894 94 obj->adcReg->PRESCALE.WORD = ((True << ADC_PRESCALE_EN_BIT_POS) |
elessair 0:f269e3021894 95 (7 << ADC_PRESCALE_VAL_BIT_POS)); /* ADC clock = 32MHz/(Prescale + 1) */
elessair 0:f269e3021894 96
elessair 0:f269e3021894 97 obj->adcReg->DELAY.WORD = ((0x34 << ADC_DELAY_SAMPLE_RATE_BIT_POS) | /** 25 uS Sets the sample rate in units of PCLKperiod * (Prescale + 1). */
elessair 0:f269e3021894 98 (0x05 << ADC_DELAY_WARMUP_BIT_POS) | /** 12.5 uS Sets the measure time in units of PCLKperiod * (Prescale + 1). */
elessair 0:f269e3021894 99 (0x1A << ADC_DELAY_SAMPLE_TIME_BIT_POS)); /** 2.5 uS Sets the warm-up time in units of PCLKperiod * (Prescale + 1). */
elessair 0:f269e3021894 100
elessair 0:f269e3021894 101 obj->adcReg->IR = 0; /** No interrupt generated */
elessair 0:f269e3021894 102 } else {
elessair 0:f269e3021894 103 obj->adcConf->convCh = adc_pin;
elessair 0:f269e3021894 104
elessair 0:f269e3021894 105 /* ADC register settings */
elessair 0:f269e3021894 106 if((obj->adcConf->measurementType) == ADC_RELATIVE_MEAS) {
elessair 0:f269e3021894 107 obj->adcReg->CONTROL.WORD = ((obj->adcConf->mode << ADC_CONTROL_MODE_BIT_POS) |
elessair 0:f269e3021894 108 (obj->adcConf->measurementType << ADC_CONTROL_MEASTYPE_BIT_POS) |
elessair 0:f269e3021894 109 (obj->adcConf->inputScale << ADC_CONTROL_INPUTSCALE_BIT_POS) |
elessair 0:f269e3021894 110 (obj->adcConf->convCh << ADC_CONTROL_MEAS_CH_BIT_POS) |
elessair 0:f269e3021894 111 (obj->adcConf->referenceCh << ADC_CONTROL_REF_CH_BIT_POS));
elessair 0:f269e3021894 112 } else {
elessair 0:f269e3021894 113 obj->adcReg->CONTROL.WORD = ((obj->adcConf->mode << ADC_CONTROL_MODE_BIT_POS) |
elessair 0:f269e3021894 114 (obj->adcConf->measurementType << ADC_CONTROL_MEASTYPE_BIT_POS) |
elessair 0:f269e3021894 115 (obj->adcConf->inputScale << ADC_CONTROL_INPUTSCALE_BIT_POS) |
elessair 0:f269e3021894 116 (obj->adcConf->convCh << ADC_CONTROL_MEAS_CH_BIT_POS));
elessair 0:f269e3021894 117 }
elessair 0:f269e3021894 118
elessair 0:f269e3021894 119 obj->adcReg->PRESCALE.WORD = ((True << ADC_PRESCALE_EN_BIT_POS) |
elessair 0:f269e3021894 120 (obj->adcConf->PrescaleVal << ADC_PRESCALE_VAL_BIT_POS)); /* ADC clock = 32MHz/(Prescale + 1) */
elessair 0:f269e3021894 121
elessair 0:f269e3021894 122 obj->adcReg->DELAY.WORD = ((obj->adcConf->samplingRate << ADC_DELAY_SAMPLE_RATE_BIT_POS) | /** 25 uS Sets the sample rate in units of PCLKperiod * (Prescale + 1). */
elessair 0:f269e3021894 123 (obj->adcConf->WarmUpTime << ADC_DELAY_WARMUP_BIT_POS) | /** 12.5 uS Sets the measure time in units of PCLKperiod * (Prescale + 1). */
elessair 0:f269e3021894 124 (obj->adcConf->samplingTime << ADC_DELAY_SAMPLE_TIME_BIT_POS)); /** 2.5 uS Sets the warm-up time in units of PCLKperiod * (Prescale + 1). */
elessair 0:f269e3021894 125
elessair 0:f269e3021894 126 obj->adcReg->IR = obj->adcConf->interruptConfig; /** Interrupt setting */
elessair 0:f269e3021894 127 }
elessair 0:f269e3021894 128
elessair 0:f269e3021894 129 /* Enable interrupt */
elessair 0:f269e3021894 130 NVIC_ClearPendingIRQ(Adc_IRQn);
elessair 0:f269e3021894 131 NVIC_EnableIRQ(Adc_IRQn);
elessair 0:f269e3021894 132 }
elessair 0:f269e3021894 133
elessair 0:f269e3021894 134 /** Read the input voltage, represented as a float in the range [0.0, 1.0]
elessair 0:f269e3021894 135 *
elessair 0:f269e3021894 136 * @param obj The analogin object
elessair 0:f269e3021894 137 * @return A floating value representing the current input voltage
elessair 0:f269e3021894 138 */
elessair 0:f269e3021894 139 float analogin_read(analogin_t *obj)
elessair 0:f269e3021894 140 {
elessair 0:f269e3021894 141 float retVal = 0.0;
elessair 0:f269e3021894 142 uint16_t value = analogin_read_u16(obj);
elessair 0:f269e3021894 143 retVal = (float)value * (1.0f / (float)0x03FF);
elessair 0:f269e3021894 144 return(retVal);
elessair 0:f269e3021894 145 }
elessair 0:f269e3021894 146
elessair 0:f269e3021894 147 /** Read the value from analogin pin, represented as an unsigned 16bit value
elessair 0:f269e3021894 148 *
elessair 0:f269e3021894 149 * @param obj The analogin object
elessair 0:f269e3021894 150 * @return An unsigned 16bit value representing the current input voltage
elessair 0:f269e3021894 151 */
elessair 0:f269e3021894 152 uint16_t analogin_read_u16(analogin_t *obj)
elessair 0:f269e3021894 153 {
elessair 0:f269e3021894 154 uint16_t adcData = 0;
elessair 0:f269e3021894 155 uint8_t adc_pin = 0;
elessair 0:f269e3021894 156
elessair 0:f269e3021894 157 CLOCK_ENABLE(CLOCK_ADC);
elessair 0:f269e3021894 158
elessair 0:f269e3021894 159 if (obj->pinFlag) {
elessair 0:f269e3021894 160 switch (obj->pin) {
elessair 0:f269e3021894 161 case A0:
elessair 0:f269e3021894 162 adc_pin=0;
elessair 0:f269e3021894 163 break;
elessair 0:f269e3021894 164 case A1:
elessair 0:f269e3021894 165 adc_pin = 1;
elessair 0:f269e3021894 166 break;
elessair 0:f269e3021894 167 case A2:
elessair 0:f269e3021894 168 adc_pin = 2;
elessair 0:f269e3021894 169 break;
elessair 0:f269e3021894 170 case A3:
elessair 0:f269e3021894 171 adc_pin = 3;
elessair 0:f269e3021894 172 break;
elessair 0:f269e3021894 173 default:
elessair 0:f269e3021894 174 break;
elessair 0:f269e3021894 175 }
elessair 0:f269e3021894 176
elessair 0:f269e3021894 177 /* Re initialize the pin configured for ADC read */
elessair 0:f269e3021894 178 obj->adcReg->CONTROL.BITS.CONV_CH = adc_pin;
elessair 0:f269e3021894 179 }
elessair 0:f269e3021894 180
elessair 0:f269e3021894 181 obj->adcReg->CONTROL.BITS.START_CONV=1; /* Start The Conversion */
elessair 0:f269e3021894 182
elessair 0:f269e3021894 183 while((uint32_t)(obj->adcReg->STATUS)!=(uint32_t)1) {
elessair 0:f269e3021894 184 }
elessair 0:f269e3021894 185 adcData =(uint16_t)(obj->adcReg->DATA);
elessair 0:f269e3021894 186 CLOCK_DISABLE(CLOCK_ADC);
elessair 0:f269e3021894 187
elessair 0:f269e3021894 188 return(adcData);
elessair 0:f269e3021894 189 }
elessair 0:f269e3021894 190
elessair 0:f269e3021894 191 #endif // DEVICE_ANALOGIN
elessair 0:f269e3021894 192