mirror of https://github.com/ARMmbed/mbed-os.git
96 lines
3.4 KiB
C
96 lines
3.4 KiB
C
/*******************************************************************************
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* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is 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 included
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* 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, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
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* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*
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* Except as contained in this notice, the name of Maxim Integrated
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* Products, Inc. shall not be used except as stated in the Maxim Integrated
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* Products, Inc. Branding Policy.
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*
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* The mere transfer of this software does not imply any licenses
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* of trade secrets, proprietary technology, copyrights, patents,
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* trademarks, maskwork rights, or any other form of intellectual
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* property whatsoever. Maxim Integrated Products, Inc. retains all
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* ownership rights.
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*******************************************************************************
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*/
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#include "mbed_assert.h"
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#include "analogin_api.h"
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#include "adc.h"
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#include "pinmap.h"
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#include "PeripheralPins.h"
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#define ADC_FULL_SCALE 0x3FFU
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#define INT_FULL_SCALE 0xFFFFU
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#define FLOAT_FULL_SCALE 1.0f
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static int initialized = 0;
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//******************************************************************************
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void analogin_init(analogin_t *obj, PinName pin)
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{
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// Make sure pin is an analog pin we can use for ADC
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MBED_ASSERT((ADCName)pinmap_peripheral(pin, PinMap_ADC) != (ADCName)NC);
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// Set the object pointer and channel encoding
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obj->adc = MXC_ADC;
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obj->channel = (mxc_adc_chsel_t)pinmap_find_function(pin, PinMap_ADC);
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if (!initialized) {
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MBED_ASSERT(ADC_Init() == E_NO_ERROR);
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initialized = 1;
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}
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}
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//******************************************************************************
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float analogin_read(analogin_t *obj)
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{
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uint16_t tmp;
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float result;
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// Start conversion with no input scaling and no input buffer bypass
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ADC_StartConvert(obj->channel, 1, 0);
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if (ADC_GetData(&tmp) == E_OVERFLOW) {
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result = FLOAT_FULL_SCALE;
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} else {
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result = (float)tmp * (FLOAT_FULL_SCALE / (float)ADC_FULL_SCALE);
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}
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return result;
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}
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//******************************************************************************
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uint16_t analogin_read_u16(analogin_t *obj)
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{
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uint16_t tmp;
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uint16_t result;
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// Start conversion with no input scaling and no input buffer bypass
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ADC_StartConvert(obj->channel, 1, 0);
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if (ADC_GetData(&tmp) == E_OVERFLOW) {
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result = INT_FULL_SCALE;
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} else {
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result = ((tmp << 6) & 0xFFC0) | ((tmp >> 4) & 0x003F);
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}
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return result;
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}
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