EL4121 Embedded System / mbed-os

mbed-os

Dependents:   cobaLCDJoyMotor_Thread odometry_omni_3roda_v3 odometry_omni_3roda_v1 odometry_omni_3roda_v2 ... more

targets/TARGET_NXP/TARGET_LPC43XX/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 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
be_bryan 0:b74591d5ab33 17 */
be_bryan 0:b74591d5ab33 18 #include "mbed_assert.h"
be_bryan 0:b74591d5ab33 19 #include "analogin_api.h"
be_bryan 0:b74591d5ab33 20 #include "cmsis.h"
be_bryan 0:b74591d5ab33 21 #include "pinmap.h"
be_bryan 0:b74591d5ab33 22 #include "mbed_error.h"
be_bryan 0:b74591d5ab33 23 #include "gpio_api.h"
be_bryan 0:b74591d5ab33 24
be_bryan 0:b74591d5ab33 25 #define ANALOGIN_MEDIAN_FILTER 1
be_bryan 0:b74591d5ab33 26
be_bryan 0:b74591d5ab33 27 static inline int div_round_up(int x, int y) {
be_bryan 0:b74591d5ab33 28 return (x + (y - 1)) / y;
be_bryan 0:b74591d5ab33 29 }
be_bryan 0:b74591d5ab33 30
be_bryan 0:b74591d5ab33 31 static const PinMap PinMap_ADC[] = {
be_bryan 0:b74591d5ab33 32 {P4_3, ADC0_0, 0},
be_bryan 0:b74591d5ab33 33 {P4_1, ADC0_1, 0},
be_bryan 0:b74591d5ab33 34 {PF_8, ADC0_2, 0},
be_bryan 0:b74591d5ab33 35 {P7_5, ADC0_3, 0},
be_bryan 0:b74591d5ab33 36 {P7_4, ADC0_4, 0},
be_bryan 0:b74591d5ab33 37 {PF_10, ADC0_5, 0},
be_bryan 0:b74591d5ab33 38 {PB_6, ADC0_6, 0},
be_bryan 0:b74591d5ab33 39 {PC_3, ADC1_0, 0},
be_bryan 0:b74591d5ab33 40 {PC_0, ADC1_1, 0},
be_bryan 0:b74591d5ab33 41 {PF_9, ADC1_2, 0},
be_bryan 0:b74591d5ab33 42 {PF_6, ADC1_3, 0},
be_bryan 0:b74591d5ab33 43 {PF_5, ADC1_4, 0},
be_bryan 0:b74591d5ab33 44 {PF_11, ADC1_5, 0},
be_bryan 0:b74591d5ab33 45 {P7_7, ADC1_6, 0},
be_bryan 0:b74591d5ab33 46 {PF_7, ADC1_7, 0},
be_bryan 0:b74591d5ab33 47 {adc0_0, ADC_pin0_0, 0},
be_bryan 0:b74591d5ab33 48 {adc0_1, ADC_pin0_1, 0},
be_bryan 0:b74591d5ab33 49 {adc0_2, ADC_pin0_2, 0},
be_bryan 0:b74591d5ab33 50 {adc0_3, ADC_pin0_3, 0},
be_bryan 0:b74591d5ab33 51 {adc0_4, ADC_pin0_4, 0},
be_bryan 0:b74591d5ab33 52 {adc0_5, ADC_pin0_5, 0},
be_bryan 0:b74591d5ab33 53 {adc0_6, ADC_pin0_6, 0},
be_bryan 0:b74591d5ab33 54 {adc0_7, ADC_pin0_7, 0},
be_bryan 0:b74591d5ab33 55 {adc1_0, ADC_pin1_0, 0},
be_bryan 0:b74591d5ab33 56 {adc1_1, ADC_pin1_1, 0},
be_bryan 0:b74591d5ab33 57 {adc1_2, ADC_pin1_2, 0},
be_bryan 0:b74591d5ab33 58 {adc1_3, ADC_pin1_3, 0},
be_bryan 0:b74591d5ab33 59 {adc1_4, ADC_pin1_4, 0},
be_bryan 0:b74591d5ab33 60 {adc1_5, ADC_pin1_5, 0},
be_bryan 0:b74591d5ab33 61 {adc1_6, ADC_pin1_6, 0},
be_bryan 0:b74591d5ab33 62 {adc1_7, ADC_pin1_7, 0},
be_bryan 0:b74591d5ab33 63 {NC, NC, 0 }
be_bryan 0:b74591d5ab33 64 };
be_bryan 0:b74591d5ab33 65
be_bryan 0:b74591d5ab33 66 void analogin_init(analogin_t *obj, PinName pin) {
be_bryan 0:b74591d5ab33 67 ADCName name;
be_bryan 0:b74591d5ab33 68
be_bryan 0:b74591d5ab33 69 name = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
be_bryan 0:b74591d5ab33 70 MBED_ASSERT(obj->adc != (LPC_ADC_T *)NC);
be_bryan 0:b74591d5ab33 71
be_bryan 0:b74591d5ab33 72 // Set ADC number
be_bryan 0:b74591d5ab33 73 if(name < ADC1_0) {
be_bryan 0:b74591d5ab33 74 obj->num = 0;
be_bryan 0:b74591d5ab33 75 } else if(name < ADC_pin0_0 && name > ADC0_6) {
be_bryan 0:b74591d5ab33 76 obj->num = 1;
be_bryan 0:b74591d5ab33 77 } else if(name < ADC_pin1_1 && name > ADC1_7) {
be_bryan 0:b74591d5ab33 78 obj->num = 0;
be_bryan 0:b74591d5ab33 79 } else if(name > ADC_pin0_7) {
be_bryan 0:b74591d5ab33 80 obj->num = 1;
be_bryan 0:b74591d5ab33 81 }
be_bryan 0:b74591d5ab33 82
be_bryan 0:b74591d5ab33 83 //ADC register and channel
be_bryan 0:b74591d5ab33 84 obj->ch = name % (ADC0_7 + 1);
be_bryan 0:b74591d5ab33 85 obj->adc = (LPC_ADC_T *) (obj->num > 0) ? LPC_ADC1 : LPC_ADC0;
be_bryan 0:b74591d5ab33 86
be_bryan 0:b74591d5ab33 87 // Reset pin function to GPIO if it is a GPIO pin. for adc only pins it is not necessary
be_bryan 0:b74591d5ab33 88 if(name < ADC_pin0_0) {
be_bryan 0:b74591d5ab33 89 gpio_set(pin);
be_bryan 0:b74591d5ab33 90 // Select ADC on analog function select register in SCU
be_bryan 0:b74591d5ab33 91 LPC_SCU->ENAIO[obj->num] |= (1 << obj->ch);
be_bryan 0:b74591d5ab33 92 } else {
be_bryan 0:b74591d5ab33 93 LPC_SCU->ENAIO[obj->num] &= ~(1 << obj->ch);
be_bryan 0:b74591d5ab33 94 }
be_bryan 0:b74591d5ab33 95
be_bryan 0:b74591d5ab33 96 // Calculate minimum clock divider
be_bryan 0:b74591d5ab33 97 // clkdiv = divider - 1
be_bryan 0:b74591d5ab33 98 uint32_t PCLK = SystemCoreClock;
be_bryan 0:b74591d5ab33 99 uint32_t adcRate = 400000;
be_bryan 0:b74591d5ab33 100 uint32_t clkdiv = div_round_up(PCLK, adcRate) - 1;
be_bryan 0:b74591d5ab33 101
be_bryan 0:b74591d5ab33 102 // Set the generic software-controlled ADC settings
be_bryan 0:b74591d5ab33 103 obj->adc->CR = (0 << 0) // SEL: 0 = no channels selected
be_bryan 0:b74591d5ab33 104 | (clkdiv << 8) // CLKDIV:
be_bryan 0:b74591d5ab33 105 | (0 << 16) // BURST: 0 = software control
be_bryan 0:b74591d5ab33 106 | (1 << 21) // PDN: 1 = operational
be_bryan 0:b74591d5ab33 107 | (0 << 24) // START: 0 = no start
be_bryan 0:b74591d5ab33 108 | (0 << 27); // EDGE: not applicable
be_bryan 0:b74591d5ab33 109 }
be_bryan 0:b74591d5ab33 110
be_bryan 0:b74591d5ab33 111 static inline uint32_t adc_read(analogin_t *obj) {
be_bryan 0:b74591d5ab33 112 uint32_t temp;
be_bryan 0:b74591d5ab33 113 uint8_t channel = obj->ch;
be_bryan 0:b74591d5ab33 114 LPC_ADC_T *pADC = obj->adc;
be_bryan 0:b74591d5ab33 115
be_bryan 0:b74591d5ab33 116 // Select the appropriate channel and start conversion
be_bryan 0:b74591d5ab33 117 pADC->CR |= ADC_CR_CH_SEL(channel);
be_bryan 0:b74591d5ab33 118 temp = pADC->CR & ~ADC_CR_START_MASK;
be_bryan 0:b74591d5ab33 119 pADC->CR = temp | (ADC_CR_START_MODE_SEL(ADC_START_NOW));
be_bryan 0:b74591d5ab33 120
be_bryan 0:b74591d5ab33 121 // Wait for DONE bit and read data
be_bryan 0:b74591d5ab33 122 while (!(pADC->STAT & ADC_CR_CH_SEL(channel)));
be_bryan 0:b74591d5ab33 123 temp = pADC->DR[channel];
be_bryan 0:b74591d5ab33 124
be_bryan 0:b74591d5ab33 125 // Deselect channel and return result
be_bryan 0:b74591d5ab33 126 pADC->CR &= ~ADC_CR_START_MASK;
be_bryan 0:b74591d5ab33 127 pADC->CR &= ~ADC_CR_CH_SEL(channel);
be_bryan 0:b74591d5ab33 128 return ADC_DR_RESULT(temp);
be_bryan 0:b74591d5ab33 129 }
be_bryan 0:b74591d5ab33 130
be_bryan 0:b74591d5ab33 131 static inline void order(uint32_t *a, uint32_t *b) {
be_bryan 0:b74591d5ab33 132 if (*a > *b) {
be_bryan 0:b74591d5ab33 133 uint32_t t = *a;
be_bryan 0:b74591d5ab33 134 *a = *b;
be_bryan 0:b74591d5ab33 135 *b = t;
be_bryan 0:b74591d5ab33 136 }
be_bryan 0:b74591d5ab33 137 }
be_bryan 0:b74591d5ab33 138
be_bryan 0:b74591d5ab33 139 static inline uint32_t adc_read_u32(analogin_t *obj) {
be_bryan 0:b74591d5ab33 140 uint32_t value;
be_bryan 0:b74591d5ab33 141 #if ANALOGIN_MEDIAN_FILTER
be_bryan 0:b74591d5ab33 142 uint32_t v1 = adc_read(obj);
be_bryan 0:b74591d5ab33 143 uint32_t v2 = adc_read(obj);
be_bryan 0:b74591d5ab33 144 uint32_t v3 = adc_read(obj);
be_bryan 0:b74591d5ab33 145 order(&v1, &v2);
be_bryan 0:b74591d5ab33 146 order(&v2, &v3);
be_bryan 0:b74591d5ab33 147 order(&v1, &v2);
be_bryan 0:b74591d5ab33 148 value = v2;
be_bryan 0:b74591d5ab33 149 #else
be_bryan 0:b74591d5ab33 150 value = adc_read(obj);
be_bryan 0:b74591d5ab33 151 #endif
be_bryan 0:b74591d5ab33 152 return value;
be_bryan 0:b74591d5ab33 153 }
be_bryan 0:b74591d5ab33 154
be_bryan 0:b74591d5ab33 155 uint16_t analogin_read_u16(analogin_t *obj) {
be_bryan 0:b74591d5ab33 156 uint32_t value = adc_read_u32(obj);
be_bryan 0:b74591d5ab33 157
be_bryan 0:b74591d5ab33 158 return (value << 6) | ((value >> 4) & 0x003F); // 10 bit
be_bryan 0:b74591d5ab33 159 }
be_bryan 0:b74591d5ab33 160
be_bryan 0:b74591d5ab33 161 float analogin_read(analogin_t *obj) {
be_bryan 0:b74591d5ab33 162 uint32_t value = adc_read_u32(obj);
be_bryan 0:b74591d5ab33 163 return (float)value * (1.0f / (float)ADC_RANGE);
be_bryan 0:b74591d5ab33 164 }