mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_NXP/TARGET_LPC11U6X/analogin_api.c@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
Parent:
149:156823d33999 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2013 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 17 #include "analogin_api.h"
<> 144:ef7eb2e8f9f7 18 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 19 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 20 #include "mbed_error.h"
<> 144:ef7eb2e8f9f7 21
<> 144:ef7eb2e8f9f7 22 #if DEVICE_ANALOGIN
<> 144:ef7eb2e8f9f7 23
<> 144:ef7eb2e8f9f7 24 #define ANALOGIN_MEDIAN_FILTER 1
<> 144:ef7eb2e8f9f7 25
<> 144:ef7eb2e8f9f7 26 #define ADC_10BIT_RANGE 0x3FF
<> 144:ef7eb2e8f9f7 27 #define ADC_12BIT_RANGE 0xFFF
<> 144:ef7eb2e8f9f7 28 #define PDRUN_VALID_BITS 0x000025FFL
<> 144:ef7eb2e8f9f7 29 #define PDRUN_RESERVED_ONE 0x0000C800L
<> 144:ef7eb2e8f9f7 30
<> 144:ef7eb2e8f9f7 31 #define ADC_RANGE ADC_12BIT_RANGE
<> 144:ef7eb2e8f9f7 32
<> 144:ef7eb2e8f9f7 33 static const PinMap PinMap_ADC[] = {
<> 144:ef7eb2e8f9f7 34 {P1_9 , ADC_0, 3},
<> 144:ef7eb2e8f9f7 35 {P0_23, ADC_1, 1},
<> 144:ef7eb2e8f9f7 36 {P0_16, ADC_2, 1},
<> 144:ef7eb2e8f9f7 37 {P0_15, ADC_3, 3},
<> 144:ef7eb2e8f9f7 38 {P1_22, ADC_4, 3},
<> 144:ef7eb2e8f9f7 39 {P1_3 , ADC_5, 4},
<> 144:ef7eb2e8f9f7 40 {P0_14, ADC_6, 2},
<> 144:ef7eb2e8f9f7 41 {P0_13, ADC_7, 2},
<> 144:ef7eb2e8f9f7 42 {P0_12, ADC_8, 2},
<> 144:ef7eb2e8f9f7 43 {P0_11, ADC_9, 2},
<> 144:ef7eb2e8f9f7 44 {P1_29, ADC_10,4},
<> 144:ef7eb2e8f9f7 45 {P0_22, ADC_11,1},
<> 144:ef7eb2e8f9f7 46 {NC , NC ,0}
<> 144:ef7eb2e8f9f7 47 };
<> 144:ef7eb2e8f9f7 48
<> 144:ef7eb2e8f9f7 49
<> 144:ef7eb2e8f9f7 50 void analogin_init(analogin_t *obj, PinName pin) {
<> 144:ef7eb2e8f9f7 51 volatile uint32_t tmp;
<> 144:ef7eb2e8f9f7 52 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
<> 144:ef7eb2e8f9f7 53 MBED_ASSERT(obj->adc != (ADCName)NC);
<> 144:ef7eb2e8f9f7 54
<> 144:ef7eb2e8f9f7 55 pinmap_pinout(pin, PinMap_ADC);
<> 144:ef7eb2e8f9f7 56
<> 144:ef7eb2e8f9f7 57 __IO uint32_t *reg = (__IO uint32_t*)(LPC_IOCON_BASE + (pin & 0x1FF));
<> 144:ef7eb2e8f9f7 58 // set pin to ADC mode
<> 144:ef7eb2e8f9f7 59 *reg &= ~(1 << 7); // set ADMODE = 0 (analog mode)
<> 144:ef7eb2e8f9f7 60
<> 144:ef7eb2e8f9f7 61 // ADC Powered
<> 144:ef7eb2e8f9f7 62 tmp = (LPC_SYSCON->PDRUNCFG & PDRUN_VALID_BITS);
<> 144:ef7eb2e8f9f7 63 tmp &= ~((1 << 4) & PDRUN_VALID_BITS);
<> 144:ef7eb2e8f9f7 64 LPC_SYSCON->PDRUNCFG = (tmp | PDRUN_RESERVED_ONE);
<> 144:ef7eb2e8f9f7 65
<> 144:ef7eb2e8f9f7 66 // Enable clock for ADC
<> 144:ef7eb2e8f9f7 67 LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 13);
<> 144:ef7eb2e8f9f7 68
<> 144:ef7eb2e8f9f7 69 // Determine the clock divider for a 500kHz ADC clock during calibration
<> 144:ef7eb2e8f9f7 70 uint32_t clkdiv = (SystemCoreClock / 500000) - 1;
<> 144:ef7eb2e8f9f7 71
<> 144:ef7eb2e8f9f7 72 // Perform a self-calibration
<> 144:ef7eb2e8f9f7 73 LPC_ADC->CTRL = (1UL << 30) | (clkdiv & 0xFF);
<> 144:ef7eb2e8f9f7 74 while ((LPC_ADC->CTRL & (1UL << 30)) != 0);
<> 144:ef7eb2e8f9f7 75
<> 144:ef7eb2e8f9f7 76 // Sampling clock: SystemClock divided by 1
<> 144:ef7eb2e8f9f7 77 LPC_ADC->CTRL = 0;
<> 144:ef7eb2e8f9f7 78 }
<> 144:ef7eb2e8f9f7 79
<> 144:ef7eb2e8f9f7 80 static inline uint32_t adc_read(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 81
<> 144:ef7eb2e8f9f7 82 // select channel
<> 144:ef7eb2e8f9f7 83 LPC_ADC->SEQA_CTRL &= ~(0xFFF);
<> 144:ef7eb2e8f9f7 84 LPC_ADC->SEQA_CTRL |= (1UL << obj->adc);
<> 144:ef7eb2e8f9f7 85
<> 144:ef7eb2e8f9f7 86 // start conversion, sequence enable with async mode
<> 144:ef7eb2e8f9f7 87 LPC_ADC->SEQA_CTRL |= ((1UL << 26) | (1UL << 31) | (1UL << 19));
<> 144:ef7eb2e8f9f7 88
<> 144:ef7eb2e8f9f7 89 // Repeatedly get the sample data until DONE bit
<> 144:ef7eb2e8f9f7 90 volatile uint32_t data;
<> 144:ef7eb2e8f9f7 91 do {
<> 144:ef7eb2e8f9f7 92 data = LPC_ADC->SEQA_GDAT;
<> 144:ef7eb2e8f9f7 93 } while ((data & (1UL << 31)) == 0);
<> 144:ef7eb2e8f9f7 94 data = LPC_ADC->DAT[obj->adc];
<> 144:ef7eb2e8f9f7 95
<> 144:ef7eb2e8f9f7 96 // Stop conversion
<> 144:ef7eb2e8f9f7 97 LPC_ADC->SEQA_CTRL &= ~(1UL << 31);
<> 144:ef7eb2e8f9f7 98
<> 144:ef7eb2e8f9f7 99 return ((data >> 4) & ADC_RANGE);
<> 144:ef7eb2e8f9f7 100 }
<> 144:ef7eb2e8f9f7 101
<> 144:ef7eb2e8f9f7 102 static inline void order(uint32_t *a, uint32_t *b) {
<> 144:ef7eb2e8f9f7 103 if (*a > *b) {
<> 144:ef7eb2e8f9f7 104 uint32_t t = *a;
<> 144:ef7eb2e8f9f7 105 *a = *b;
<> 144:ef7eb2e8f9f7 106 *b = t;
<> 144:ef7eb2e8f9f7 107 }
<> 144:ef7eb2e8f9f7 108 }
<> 144:ef7eb2e8f9f7 109
<> 144:ef7eb2e8f9f7 110 static inline uint32_t adc_read_u32(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 111 uint32_t value;
<> 144:ef7eb2e8f9f7 112 #if ANALOGIN_MEDIAN_FILTER
<> 144:ef7eb2e8f9f7 113 uint32_t v1 = adc_read(obj);
<> 144:ef7eb2e8f9f7 114 uint32_t v2 = adc_read(obj);
<> 144:ef7eb2e8f9f7 115 uint32_t v3 = adc_read(obj);
<> 144:ef7eb2e8f9f7 116 order(&v1, &v2);
<> 144:ef7eb2e8f9f7 117 order(&v2, &v3);
<> 144:ef7eb2e8f9f7 118 order(&v1, &v2);
<> 144:ef7eb2e8f9f7 119 value = v2;
<> 144:ef7eb2e8f9f7 120 #else
<> 144:ef7eb2e8f9f7 121 value = adc_read(obj);
<> 144:ef7eb2e8f9f7 122 #endif
<> 144:ef7eb2e8f9f7 123 return value;
<> 144:ef7eb2e8f9f7 124 }
<> 144:ef7eb2e8f9f7 125
<> 144:ef7eb2e8f9f7 126 uint16_t analogin_read_u16(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 127 uint32_t value = adc_read_u32(obj);
<> 144:ef7eb2e8f9f7 128 return (value << 4) | ((value >> 8) & 0x000F); // 12 bit
<> 144:ef7eb2e8f9f7 129 }
<> 144:ef7eb2e8f9f7 130
<> 144:ef7eb2e8f9f7 131 float analogin_read(analogin_t *obj) {
<> 144:ef7eb2e8f9f7 132 uint32_t value = adc_read_u32(obj);
<> 144:ef7eb2e8f9f7 133 return (float)value * (1.0f / (float)ADC_RANGE);
<> 144:ef7eb2e8f9f7 134 }
<> 144:ef7eb2e8f9f7 135
<> 144:ef7eb2e8f9f7 136 #endif