[352] | 1 | /* mbed Microcontroller Library
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| 2 | * Copyright (c) 2006-2013 ARM Limited
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| 3 | *
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| 4 | * Licensed under the Apache License, Version 2.0 (the "License");
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| 5 | * you may not use this file except in compliance with the License.
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| 6 | * You may obtain a copy of the License at
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| 7 | *
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| 8 | * http://www.apache.org/licenses/LICENSE-2.0
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| 9 | *
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| 10 | * Unless required by applicable law or agreed to in writing, software
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| 11 | * distributed under the License is distributed on an "AS IS" BASIS,
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| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| 13 | * See the License for the specific language governing permissions and
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| 14 | * limitations under the License.
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| 15 | */
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| 16 | #include "mbed_assert.h"
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| 17 | #include "analogin_api.h"
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| 18 |
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| 19 | #include "cmsis.h"
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[374] | 20 | #include "PeripheralPins.h"
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[352] | 21 |
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[374] | 22 | #include "iodefine.h"
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[352] | 23 |
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| 24 | #define ANALOGIN_MEDIAN_FILTER 0
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| 25 |
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| 26 | static volatile uint16_t *ADCDR[] = {
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| 27 | &ADCADDRA,
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| 28 | &ADCADDRB,
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| 29 | &ADCADDRC,
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| 30 | &ADCADDRD,
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| 31 | &ADCADDRE,
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| 32 | &ADCADDRF,
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| 33 | &ADCADDRG,
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| 34 | &ADCADDRH,
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| 35 | };
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| 36 |
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| 37 | void analogin_init(analogin_t *obj, PinName pin) {
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| 38 | obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
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| 39 | MBED_ASSERT(obj->adc != (ADCName)NC);
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| 40 |
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| 41 | CPGSTBCR3 &= ~(1 << 1);
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| 42 | CPGSTBCR6 &= ~(1 << 7);
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| 43 |
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| 44 | // 15: ADF 14: ADIE 13: ADST, [12:9] TRGS..0
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| 45 | // [8:6] CKS 010 :: 340tclk
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| 46 | // [5:3] MDS 000 :: single mode
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| 47 | // [2:0] CH 000 :: AN0
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| 48 | ADCADCSR = 0x0080;
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| 49 |
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| 50 | pinmap_pinout(pin, PinMap_ADC);
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| 51 | }
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| 52 |
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| 53 | static inline uint32_t adc_read(analogin_t *obj) {
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| 54 | volatile uint16_t data;
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| 55 |
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| 56 | // Select the appropriate channel and start conversion
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| 57 | ADCADCSR &= 0xfff8;
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| 58 | ADCADCSR |= (1 << 13 | (obj->adc & 0x7));
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| 59 |
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| 60 | // Wait end of conversion
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| 61 | do {
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| 62 | data = ADCADCSR;
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| 63 | } while (((data & (1 << 15)) == 0) || ((data & (1 << 13)) != 0));
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| 64 |
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| 65 | // clear flag
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| 66 | ADCADCSR &= ~(1 << 15);
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| 67 |
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| 68 | return ((*(ADCDR[obj->adc])) >> 4) & 0x0FFF; // 12 bits range
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| 69 | }
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| 70 |
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| 71 | #if ANALOGIN_MEDIAN_FILTER
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| 72 | static inline void order(uint32_t *a, uint32_t *b) {
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| 73 | if (*a > *b) {
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| 74 | uint32_t t = *a;
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| 75 | *a = *b;
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| 76 | *b = t;
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| 77 | }
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| 78 | }
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| 79 | #endif
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| 80 |
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| 81 | static inline uint32_t adc_read_u32(analogin_t *obj) {
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| 82 | uint32_t value;
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| 83 | #if ANALOGIN_MEDIAN_FILTER
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| 84 | uint32_t v1 = adc_read(obj);
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| 85 | uint32_t v2 = adc_read(obj);
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| 86 | uint32_t v3 = adc_read(obj);
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| 87 | order(&v1, &v2);
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| 88 | order(&v2, &v3);
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| 89 | order(&v1, &v2);
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| 90 | value = v2;
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| 91 | #else
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| 92 | value = adc_read(obj);
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| 93 | #endif
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| 94 | return value;
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| 95 | }
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| 96 |
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| 97 | uint16_t analogin_read_u16(analogin_t *obj) {
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| 98 | uint32_t value = adc_read_u32(obj);
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| 99 |
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| 100 | return (value << 4) | ((value >> 8) & 0x000F); // 12-bit to 16-bit conversion
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| 101 | }
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| 102 |
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| 103 | float analogin_read(analogin_t *obj) {
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| 104 | uint32_t value = adc_read_u32(obj);
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| 105 |
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| 106 | return (float)value * (1.0f / (float)0x0FFF); // 12 bits range
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| 107 | }
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