Denislam Valeev / Mbed OS Nucleo_rtos_basic

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mbed-os/targets/TARGET_NXP/TARGET_LPC82X/analogin_api.c@0:e056ac8fecf8, 2018-03-13 (annotated)

Committer:
valeyev
Date:
Tue Mar 13 07:17:50 2018 +0000
Revision:
0:e056ac8fecf8
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Who changed what in which revision?

UserRevisionLine numberNew contents of line
valeyev 0:e056ac8fecf8 1 /* mbed Microcontroller Library
valeyev 0:e056ac8fecf8 2 * Copyright (c) 2006-2013 ARM Limited
valeyev 0:e056ac8fecf8 3 *
valeyev 0:e056ac8fecf8 4 * Licensed under the Apache License, Version 2.0 (the "License");
valeyev 0:e056ac8fecf8 5 * you may not use this file except in compliance with the License.
valeyev 0:e056ac8fecf8 6 * You may obtain a copy of the License at
valeyev 0:e056ac8fecf8 7 *
valeyev 0:e056ac8fecf8 8 * http://www.apache.org/licenses/LICENSE-2.0
valeyev 0:e056ac8fecf8 9 *
valeyev 0:e056ac8fecf8 10 * Unless required by applicable law or agreed to in writing, software
valeyev 0:e056ac8fecf8 11 * distributed under the License is distributed on an "AS IS" BASIS,
valeyev 0:e056ac8fecf8 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
valeyev 0:e056ac8fecf8 13 * See the License for the specific language governing permissions and
valeyev 0:e056ac8fecf8 14 * limitations under the License.
valeyev 0:e056ac8fecf8 15 */
valeyev 0:e056ac8fecf8 16 #include "mbed_assert.h"
valeyev 0:e056ac8fecf8 17 #include "analogin_api.h"
valeyev 0:e056ac8fecf8 18 #include "cmsis.h"
valeyev 0:e056ac8fecf8 19 #include "pinmap.h"
valeyev 0:e056ac8fecf8 20 #include "PeripheralNames.h"
valeyev 0:e056ac8fecf8 21
valeyev 0:e056ac8fecf8 22 #if DEVICE_ANALOGIN
valeyev 0:e056ac8fecf8 23
valeyev 0:e056ac8fecf8 24 #define ANALOGIN_MEDIAN_FILTER 1
valeyev 0:e056ac8fecf8 25
valeyev 0:e056ac8fecf8 26 #define ADC_RANGE 0xFFF
valeyev 0:e056ac8fecf8 27
valeyev 0:e056ac8fecf8 28 static const PinMap PinMap_ADC[] = {
valeyev 0:e056ac8fecf8 29 {P0_7 , ADC_0, 0},
valeyev 0:e056ac8fecf8 30 {P0_6 , ADC_1, 0},
valeyev 0:e056ac8fecf8 31 {P0_14, ADC_2, 0},
valeyev 0:e056ac8fecf8 32 {P0_23, ADC_3, 0},
valeyev 0:e056ac8fecf8 33 {P0_22, ADC_4, 0},
valeyev 0:e056ac8fecf8 34 {P0_21, ADC_5, 0},
valeyev 0:e056ac8fecf8 35 {P0_20, ADC_6, 0},
valeyev 0:e056ac8fecf8 36 {P0_19, ADC_7, 0},
valeyev 0:e056ac8fecf8 37 {P0_18, ADC_8, 0},
valeyev 0:e056ac8fecf8 38 {P0_17, ADC_9, 0},
valeyev 0:e056ac8fecf8 39 {P0_13, ADC_10,0},
valeyev 0:e056ac8fecf8 40 {P0_4 , ADC_11,0},
valeyev 0:e056ac8fecf8 41 };
valeyev 0:e056ac8fecf8 42
valeyev 0:e056ac8fecf8 43 void analogin_init(analogin_t *obj, PinName pin)
valeyev 0:e056ac8fecf8 44 {
valeyev 0:e056ac8fecf8 45 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
valeyev 0:e056ac8fecf8 46 MBED_ASSERT(obj->adc != (ADCName)NC);
valeyev 0:e056ac8fecf8 47
valeyev 0:e056ac8fecf8 48 LPC_SYSCON->SYSAHBCLKCTRL |= (1UL << 6);
valeyev 0:e056ac8fecf8 49 // pin enable
valeyev 0:e056ac8fecf8 50 LPC_SWM->PINENABLE0 &= ~(1UL << (13 + obj->adc));
valeyev 0:e056ac8fecf8 51 // configure GPIO as input
valeyev 0:e056ac8fecf8 52 LPC_GPIO_PORT->DIR0 &= ~(1UL << (pin >> PIN_SHIFT));
valeyev 0:e056ac8fecf8 53
valeyev 0:e056ac8fecf8 54 LPC_SYSCON->PDRUNCFG &= ~(1 << 4);
valeyev 0:e056ac8fecf8 55 LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 24);
valeyev 0:e056ac8fecf8 56
valeyev 0:e056ac8fecf8 57 __IO LPC_ADC_Type *adc_reg = LPC_ADC;
valeyev 0:e056ac8fecf8 58
valeyev 0:e056ac8fecf8 59 // determine the system clock divider for a 500kHz ADC clock during calibration
valeyev 0:e056ac8fecf8 60 uint32_t clkdiv = (SystemCoreClock / 500000) - 1;
valeyev 0:e056ac8fecf8 61
valeyev 0:e056ac8fecf8 62 // perform a self-calibration
valeyev 0:e056ac8fecf8 63 adc_reg->CTRL = (1UL << 30) | (clkdiv & 0xFF);
valeyev 0:e056ac8fecf8 64 while ((adc_reg->CTRL & (1UL << 30)) != 0);
valeyev 0:e056ac8fecf8 65 }
valeyev 0:e056ac8fecf8 66
valeyev 0:e056ac8fecf8 67 static inline uint32_t adc_read(analogin_t *obj)
valeyev 0:e056ac8fecf8 68 {
valeyev 0:e056ac8fecf8 69 uint32_t channels;
valeyev 0:e056ac8fecf8 70 __IO LPC_ADC_Type *adc_reg = LPC_ADC;
valeyev 0:e056ac8fecf8 71
valeyev 0:e056ac8fecf8 72 channels = (obj->adc & 0x1F);
valeyev 0:e056ac8fecf8 73
valeyev 0:e056ac8fecf8 74 // select channel
valeyev 0:e056ac8fecf8 75 adc_reg->SEQA_CTRL &= ~(0xFFF);
valeyev 0:e056ac8fecf8 76 adc_reg->SEQA_CTRL |= (1UL << channels);
valeyev 0:e056ac8fecf8 77
valeyev 0:e056ac8fecf8 78 // start conversion and sequence enable
valeyev 0:e056ac8fecf8 79 adc_reg->SEQA_CTRL |= ((1UL << 26) | (1UL << 31));
valeyev 0:e056ac8fecf8 80
valeyev 0:e056ac8fecf8 81 // Repeatedly get the sample data until DONE bit
valeyev 0:e056ac8fecf8 82 volatile uint32_t data;
valeyev 0:e056ac8fecf8 83 do {
valeyev 0:e056ac8fecf8 84 data = adc_reg->SEQA_GDAT;
valeyev 0:e056ac8fecf8 85 } while ((data & (1UL << 31)) == 0);
valeyev 0:e056ac8fecf8 86
valeyev 0:e056ac8fecf8 87 // Stop conversion
valeyev 0:e056ac8fecf8 88 adc_reg->SEQA_CTRL &= ~(1UL << 31);
valeyev 0:e056ac8fecf8 89
valeyev 0:e056ac8fecf8 90 return ((data >> 4) & ADC_RANGE);
valeyev 0:e056ac8fecf8 91 }
valeyev 0:e056ac8fecf8 92
valeyev 0:e056ac8fecf8 93 static inline void order(uint32_t *a, uint32_t *b)
valeyev 0:e056ac8fecf8 94 {
valeyev 0:e056ac8fecf8 95 if (*a > *b) {
valeyev 0:e056ac8fecf8 96 uint32_t t = *a;
valeyev 0:e056ac8fecf8 97 *a = *b;
valeyev 0:e056ac8fecf8 98 *b = t;
valeyev 0:e056ac8fecf8 99 }
valeyev 0:e056ac8fecf8 100 }
valeyev 0:e056ac8fecf8 101
valeyev 0:e056ac8fecf8 102 static inline uint32_t adc_read_u32(analogin_t *obj)
valeyev 0:e056ac8fecf8 103 {
valeyev 0:e056ac8fecf8 104 uint32_t value;
valeyev 0:e056ac8fecf8 105 #if ANALOGIN_MEDIAN_FILTER
valeyev 0:e056ac8fecf8 106 uint32_t v1 = adc_read(obj);
valeyev 0:e056ac8fecf8 107 uint32_t v2 = adc_read(obj);
valeyev 0:e056ac8fecf8 108 uint32_t v3 = adc_read(obj);
valeyev 0:e056ac8fecf8 109 order(&v1, &v2);
valeyev 0:e056ac8fecf8 110 order(&v2, &v3);
valeyev 0:e056ac8fecf8 111 order(&v1, &v2);
valeyev 0:e056ac8fecf8 112 value = v2;
valeyev 0:e056ac8fecf8 113 #else
valeyev 0:e056ac8fecf8 114 value = adc_read(obj);
valeyev 0:e056ac8fecf8 115 #endif
valeyev 0:e056ac8fecf8 116 return value;
valeyev 0:e056ac8fecf8 117 }
valeyev 0:e056ac8fecf8 118
valeyev 0:e056ac8fecf8 119 uint16_t analogin_read_u16(analogin_t *obj)
valeyev 0:e056ac8fecf8 120 {
valeyev 0:e056ac8fecf8 121 uint32_t value = adc_read_u32(obj);
valeyev 0:e056ac8fecf8 122 return (value << 4) | ((value >> 8) & 0x000F); // 12 bit
valeyev 0:e056ac8fecf8 123 }
valeyev 0:e056ac8fecf8 124
valeyev 0:e056ac8fecf8 125 float analogin_read(analogin_t *obj)
valeyev 0:e056ac8fecf8 126 {
valeyev 0:e056ac8fecf8 127 uint32_t value = adc_read_u32(obj);
valeyev 0:e056ac8fecf8 128 return (float)value * (1.0f / (float)ADC_RANGE);
valeyev 0:e056ac8fecf8 129 }
valeyev 0:e056ac8fecf8 130
valeyev 0:e056ac8fecf8 131 #endif