mirror of https://github.com/ARMmbed/mbed-os.git
97 lines
2.4 KiB
C
97 lines
2.4 KiB
C
/* mbed Microcontroller Library
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* Copyright (c) 2006-2013 ARM Limited
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "analogin_api.h"
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#if DEVICE_ANALOGIN
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#include "cmsis.h"
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#include "pinmap.h"
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#include "error.h"
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#define ADC_10BIT_RANGE 0x3FF
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#define ADC_12BIT_RANGE 0xFFF
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static const PinMap PinMap_ADC[] = {
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{PA_0, ADC0_0, 3, 0},
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{PA_1, ADC0_1, 3, 0},
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{PA_2, ADC0_2, 3, 0},
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{PA_3, ADC0_3, 3, 0},
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{PA_4, ADC0_4, 3, 0},
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{PA_5, ADC0_5, 3, 0},
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{PA_6, ADC0_6, 3, 0},
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{PA_7, ADC0_7, 3, 0},
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{PB_0, ADC0_8, 3, 0},
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{PB_1, ADC0_9, 3, 0},
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{PC_0, ADC0_10, 3, 0},
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{PC_1, ADC0_11, 3, 0},
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{PC_2, ADC0_12, 3, 0},
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{PC_3, ADC0_13, 3, 0},
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{PC_4, ADC0_14, 3, 0},
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{PC_5, ADC0_15, 3, 0},
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{NC, NC, 0, 0}
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};
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# define ADC_RANGE ADC_12BIT_RANGE
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void analogin_init(analogin_t *obj, PinName pin) {
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obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
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if (obj->adc == (uint32_t)NC) {
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error("ADC pin mapping failed");
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}
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// ensure power is turned on
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RCC->APB1ENR |= RCC_APB2ENR_ADC1EN;
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// Enable the ADC
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ADC1->CR2 |= ADC_CR2_ADON;
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pinmap_pinout(pin, PinMap_ADC);
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}
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static inline uint32_t adc_read(analogin_t *obj) {
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// Select the appropriate channel
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ADC1->SQR3 &= ~ADC_SQR3_SQ1;
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ADC1->SQR3 |= (int) obj->adc;
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// Start conversion
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ADC1->CR2 |= ADC_CR2_SWSTART;
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// Wait for conversion to finish
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while (!(ADC1->SR & ADC_SR_EOC));
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uint32_t data = ADC1->DR;
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return data; // 12 bit
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}
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static inline uint32_t adc_read_u32(analogin_t *obj) {
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uint32_t value;
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value = adc_read(obj);
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return value;
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}
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uint16_t analogin_read_u16(analogin_t *obj) {
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uint32_t value = adc_read_u32(obj);
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return (value << 4) | ((value >> 8) & 0x000F); // 12 bit
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}
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float analogin_read(analogin_t *obj) {
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uint32_t value = adc_read_u32(obj);
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return (float)value * (1.0f / (float)ADC_RANGE);
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}
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#endif
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