EL4121 Embedded System / mbed-os

Dependents:   cobaLCDJoyMotor_Thread odometry_omni_3roda_v3 odometry_omni_3roda_v1 odometry_omni_3roda_v2 ... more

targets/TARGET_NXP/TARGET_LPC15XX/analogin_api.c@0:b74591d5ab33, 2017-12-11 (annotated)

Committer:
be_bryan
Date:
Mon Dec 11 17:54:04 2017 +0000
Revision:
0:b74591d5ab33
motor ++

Who changed what in which revision?

UserRevisionLine numberNew contents of line
be_bryan 0:b74591d5ab33 1 /* mbed Microcontroller Library
be_bryan 0:b74591d5ab33 2 * Copyright (c) 2006-2013 ARM Limited
be_bryan 0:b74591d5ab33 3 *
be_bryan 0:b74591d5ab33 4 * Licensed under the Apache License, Version 2.0 (the "License");
be_bryan 0:b74591d5ab33 5 * you may not use this file except in compliance with the License.
be_bryan 0:b74591d5ab33 6 * You may obtain a copy of the License at
be_bryan 0:b74591d5ab33 7 *
be_bryan 0:b74591d5ab33 8 * http://www.apache.org/licenses/LICENSE-2.0
be_bryan 0:b74591d5ab33 9 *
be_bryan 0:b74591d5ab33 10 * Unless required by applicable law or agreed to in writing, software
be_bryan 0:b74591d5ab33 11 * distributed under the License is distributed on an "AS IS" BASIS,
be_bryan 0:b74591d5ab33 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
be_bryan 0:b74591d5ab33 13 * See the License for the specific language governing permissions and
be_bryan 0:b74591d5ab33 14 * limitations under the License.
be_bryan 0:b74591d5ab33 15 */
be_bryan 0:b74591d5ab33 16 #include "mbed_assert.h"
be_bryan 0:b74591d5ab33 17 #include "analogin_api.h"
be_bryan 0:b74591d5ab33 18 #include "cmsis.h"
be_bryan 0:b74591d5ab33 19 #include "pinmap.h"
be_bryan 0:b74591d5ab33 20
be_bryan 0:b74591d5ab33 21 #define ANALOGIN_MEDIAN_FILTER 1
be_bryan 0:b74591d5ab33 22
be_bryan 0:b74591d5ab33 23 #define ADC_10BIT_RANGE 0x3FF
be_bryan 0:b74591d5ab33 24 #define ADC_12BIT_RANGE 0xFFF
be_bryan 0:b74591d5ab33 25
be_bryan 0:b74591d5ab33 26 #define ADC_RANGE ADC_12BIT_RANGE
be_bryan 0:b74591d5ab33 27
be_bryan 0:b74591d5ab33 28 static const PinMap PinMap_ADC[] = {
be_bryan 0:b74591d5ab33 29 {P0_8 , ADC0_0, 0},
be_bryan 0:b74591d5ab33 30 {P0_7 , ADC0_1, 0},
be_bryan 0:b74591d5ab33 31 {P0_6 , ADC0_2, 0},
be_bryan 0:b74591d5ab33 32 {P0_5 , ADC0_3, 0},
be_bryan 0:b74591d5ab33 33 {P0_4 , ADC0_4, 0},
be_bryan 0:b74591d5ab33 34 {P0_3 , ADC0_5, 0},
be_bryan 0:b74591d5ab33 35 {P0_2 , ADC0_6, 0},
be_bryan 0:b74591d5ab33 36 {P0_1 , ADC0_7, 0},
be_bryan 0:b74591d5ab33 37 {P1_0 , ADC0_8, 0},
be_bryan 0:b74591d5ab33 38 {P0_31, ADC0_9, 0},
be_bryan 0:b74591d5ab33 39 {P0_0 , ADC0_10,0},
be_bryan 0:b74591d5ab33 40 {P0_30, ADC0_11,0},
be_bryan 0:b74591d5ab33 41 {P1_1 , ADC1_0, 0},
be_bryan 0:b74591d5ab33 42 {P0_9 , ADC1_1, 0},
be_bryan 0:b74591d5ab33 43 {P0_10, ADC1_2, 0},
be_bryan 0:b74591d5ab33 44 {P0_11, ADC1_3, 0},
be_bryan 0:b74591d5ab33 45 {P1_2 , ADC1_4, 0},
be_bryan 0:b74591d5ab33 46 {P1_3 , ADC1_5, 0},
be_bryan 0:b74591d5ab33 47 {P0_13, ADC1_6, 0},
be_bryan 0:b74591d5ab33 48 {P0_14, ADC1_7, 0},
be_bryan 0:b74591d5ab33 49 {P0_15, ADC1_8, 0},
be_bryan 0:b74591d5ab33 50 {P0_16, ADC1_9, 0},
be_bryan 0:b74591d5ab33 51 {P1_4 , ADC1_10,0},
be_bryan 0:b74591d5ab33 52 {P1_5 , ADC1_11,0},
be_bryan 0:b74591d5ab33 53 };
be_bryan 0:b74591d5ab33 54
be_bryan 0:b74591d5ab33 55 void analogin_init(analogin_t *obj, PinName pin) {
be_bryan 0:b74591d5ab33 56 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
be_bryan 0:b74591d5ab33 57 MBED_ASSERT(obj->adc != (ADCName)NC);
be_bryan 0:b74591d5ab33 58
be_bryan 0:b74591d5ab33 59 uint32_t port = (pin >> 5);
be_bryan 0:b74591d5ab33 60 // enable clock for GPIOx
be_bryan 0:b74591d5ab33 61 LPC_SYSCON->SYSAHBCLKCTRL0 |= (1UL << (14 + port));
be_bryan 0:b74591d5ab33 62 // pin enable
be_bryan 0:b74591d5ab33 63 LPC_SWM->PINENABLE0 &= ~(1UL << obj->adc);
be_bryan 0:b74591d5ab33 64 // configure GPIO as input
be_bryan 0:b74591d5ab33 65 LPC_GPIO_PORT->DIR[port] &= ~(1UL << (pin & 0x1F));
be_bryan 0:b74591d5ab33 66
be_bryan 0:b74591d5ab33 67 // power up ADC
be_bryan 0:b74591d5ab33 68 if (obj->adc < ADC1_0)
be_bryan 0:b74591d5ab33 69 {
be_bryan 0:b74591d5ab33 70 // ADC0
be_bryan 0:b74591d5ab33 71 LPC_SYSCON->PDRUNCFG &= ~(1 << 10);
be_bryan 0:b74591d5ab33 72 LPC_SYSCON->SYSAHBCLKCTRL0 |= (1 << 27);
be_bryan 0:b74591d5ab33 73 }
be_bryan 0:b74591d5ab33 74 else {
be_bryan 0:b74591d5ab33 75 // ADC1
be_bryan 0:b74591d5ab33 76 LPC_SYSCON->PDRUNCFG &= ~(1 << 11);
be_bryan 0:b74591d5ab33 77 LPC_SYSCON->SYSAHBCLKCTRL0 |= (1 << 28);
be_bryan 0:b74591d5ab33 78 }
be_bryan 0:b74591d5ab33 79
be_bryan 0:b74591d5ab33 80 __IO LPC_ADC0_Type *adc_reg = (obj->adc < ADC1_0) ? (__IO LPC_ADC0_Type*)(LPC_ADC0) : (__IO LPC_ADC0_Type*)(LPC_ADC1);
be_bryan 0:b74591d5ab33 81
be_bryan 0:b74591d5ab33 82 // determine the system clock divider for a 500kHz ADC clock during calibration
be_bryan 0:b74591d5ab33 83 uint32_t clkdiv = (SystemCoreClock / 500000) - 1;
be_bryan 0:b74591d5ab33 84
be_bryan 0:b74591d5ab33 85 // perform a self-calibration
be_bryan 0:b74591d5ab33 86 adc_reg->CTRL = (1UL << 30) | (clkdiv & 0xFF);
be_bryan 0:b74591d5ab33 87 while ((adc_reg->CTRL & (1UL << 30)) != 0);
be_bryan 0:b74591d5ab33 88
be_bryan 0:b74591d5ab33 89 // Sampling clock: SystemClock divided by 1
be_bryan 0:b74591d5ab33 90 adc_reg->CTRL = 0;
be_bryan 0:b74591d5ab33 91 }
be_bryan 0:b74591d5ab33 92
be_bryan 0:b74591d5ab33 93 static inline uint32_t adc_read(analogin_t *obj) {
be_bryan 0:b74591d5ab33 94 uint32_t channels;
be_bryan 0:b74591d5ab33 95
be_bryan 0:b74591d5ab33 96 __IO LPC_ADC0_Type *adc_reg = (obj->adc < ADC1_0) ? (__IO LPC_ADC0_Type*)(LPC_ADC0) : (__IO LPC_ADC0_Type*)(LPC_ADC1);
be_bryan 0:b74591d5ab33 97
be_bryan 0:b74591d5ab33 98 if (obj->adc >= ADC1_0)
be_bryan 0:b74591d5ab33 99 channels = ((obj->adc - ADC1_0) & 0x1F);
be_bryan 0:b74591d5ab33 100 else
be_bryan 0:b74591d5ab33 101 channels = (obj->adc & 0x1F);
be_bryan 0:b74591d5ab33 102
be_bryan 0:b74591d5ab33 103 // select channel
be_bryan 0:b74591d5ab33 104 adc_reg->SEQA_CTRL &= ~(0xFFF);
be_bryan 0:b74591d5ab33 105 adc_reg->SEQA_CTRL |= (1UL << channels);
be_bryan 0:b74591d5ab33 106
be_bryan 0:b74591d5ab33 107 // start conversion and sequence enable
be_bryan 0:b74591d5ab33 108 adc_reg->SEQA_CTRL |= ((1UL << 26) | (1UL << 31));
be_bryan 0:b74591d5ab33 109
be_bryan 0:b74591d5ab33 110 // Repeatedly get the sample data until DONE bit
be_bryan 0:b74591d5ab33 111 volatile uint32_t data;
be_bryan 0:b74591d5ab33 112 do {
be_bryan 0:b74591d5ab33 113 data = adc_reg->SEQA_GDAT;
be_bryan 0:b74591d5ab33 114 } while ((data & (1UL << 31)) == 0);
be_bryan 0:b74591d5ab33 115
be_bryan 0:b74591d5ab33 116 // Stop conversion
be_bryan 0:b74591d5ab33 117 adc_reg->SEQA_CTRL &= ~(1UL << 31);
be_bryan 0:b74591d5ab33 118
be_bryan 0:b74591d5ab33 119 return ((data >> 4) & ADC_RANGE);
be_bryan 0:b74591d5ab33 120 }
be_bryan 0:b74591d5ab33 121
be_bryan 0:b74591d5ab33 122 static inline void order(uint32_t *a, uint32_t *b) {
be_bryan 0:b74591d5ab33 123 if (*a > *b) {
be_bryan 0:b74591d5ab33 124 uint32_t t = *a;
be_bryan 0:b74591d5ab33 125 *a = *b;
be_bryan 0:b74591d5ab33 126 *b = t;
be_bryan 0:b74591d5ab33 127 }
be_bryan 0:b74591d5ab33 128 }
be_bryan 0:b74591d5ab33 129
be_bryan 0:b74591d5ab33 130 static inline uint32_t adc_read_u32(analogin_t *obj) {
be_bryan 0:b74591d5ab33 131 uint32_t value;
be_bryan 0:b74591d5ab33 132 #if ANALOGIN_MEDIAN_FILTER
be_bryan 0:b74591d5ab33 133 uint32_t v1 = adc_read(obj);
be_bryan 0:b74591d5ab33 134 uint32_t v2 = adc_read(obj);
be_bryan 0:b74591d5ab33 135 uint32_t v3 = adc_read(obj);
be_bryan 0:b74591d5ab33 136 order(&v1, &v2);
be_bryan 0:b74591d5ab33 137 order(&v2, &v3);
be_bryan 0:b74591d5ab33 138 order(&v1, &v2);
be_bryan 0:b74591d5ab33 139 value = v2;
be_bryan 0:b74591d5ab33 140 #else
be_bryan 0:b74591d5ab33 141 value = adc_read(obj);
be_bryan 0:b74591d5ab33 142 #endif
be_bryan 0:b74591d5ab33 143 return value;
be_bryan 0:b74591d5ab33 144 }
be_bryan 0:b74591d5ab33 145
be_bryan 0:b74591d5ab33 146 uint16_t analogin_read_u16(analogin_t *obj) {
be_bryan 0:b74591d5ab33 147 uint32_t value = adc_read_u32(obj);
be_bryan 0:b74591d5ab33 148 return (value << 4) | ((value >> 8) & 0x000F); // 12 bit
be_bryan 0:b74591d5ab33 149 }
be_bryan 0:b74591d5ab33 150
be_bryan 0:b74591d5ab33 151 float analogin_read(analogin_t *obj) {
be_bryan 0:b74591d5ab33 152 uint32_t value = adc_read_u32(obj);
be_bryan 0:b74591d5ab33 153 return (float)value * (1.0f / (float)ADC_RANGE);
be_bryan 0:b74591d5ab33 154 }