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Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_NXP/TARGET_LPC11XX/analogin_api.c@19:398f4c622e1b, 2013-08-19 (annotated)

Committer:
bogdanm
Date:
Mon Aug 19 18:17:02 2013 +0300
Revision:
19:398f4c622e1b
Child:
20:4263a77256ae
Sync with official mbed library release 66

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 19:398f4c622e1b 1 /* mbed Microcontroller Library
bogdanm 19:398f4c622e1b 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 19:398f4c622e1b 3 *
bogdanm 19:398f4c622e1b 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 19:398f4c622e1b 5 * you may not use this file except in compliance with the License.
bogdanm 19:398f4c622e1b 6 * You may obtain a copy of the License at
bogdanm 19:398f4c622e1b 7 *
bogdanm 19:398f4c622e1b 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 19:398f4c622e1b 9 *
bogdanm 19:398f4c622e1b 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 19:398f4c622e1b 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 19:398f4c622e1b 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 19:398f4c622e1b 13 * See the License for the specific language governing permissions and
bogdanm 19:398f4c622e1b 14 * limitations under the License.
bogdanm 19:398f4c622e1b 15 */
bogdanm 19:398f4c622e1b 16 #include "analogin_api.h"
bogdanm 19:398f4c622e1b 17 #include "cmsis.h"
bogdanm 19:398f4c622e1b 18 #include "pinmap.h"
bogdanm 19:398f4c622e1b 19 #include "error.h"
bogdanm 19:398f4c622e1b 20
bogdanm 19:398f4c622e1b 21 #define ANALOGIN_MEDIAN_FILTER 1
bogdanm 19:398f4c622e1b 22
bogdanm 19:398f4c622e1b 23 #define ADC_10BIT_RANGE 0x3FF
bogdanm 19:398f4c622e1b 24 #define ADC_12BIT_RANGE 0xFFF
bogdanm 19:398f4c622e1b 25
bogdanm 19:398f4c622e1b 26 static inline int div_round_up(int x, int y) {
bogdanm 19:398f4c622e1b 27 return (x + (y - 1)) / y;
bogdanm 19:398f4c622e1b 28 }
bogdanm 19:398f4c622e1b 29
bogdanm 19:398f4c622e1b 30 static const PinMap PinMap_ADC[] = {
bogdanm 19:398f4c622e1b 31 {P0_11, ADC0_0, 2},
bogdanm 19:398f4c622e1b 32 {P1_0 , ADC0_1, 2},
bogdanm 19:398f4c622e1b 33 {P1_1 , ADC0_2, 2},
bogdanm 19:398f4c622e1b 34 {P1_2 , ADC0_3, 2},
bogdanm 19:398f4c622e1b 35 {P1_4 , ADC0_5, 1},
bogdanm 19:398f4c622e1b 36 {P1_10, ADC0_6, 1},
bogdanm 19:398f4c622e1b 37 {P1_11, ADC0_7, 1},
bogdanm 19:398f4c622e1b 38 {NC , NC , 0}
bogdanm 19:398f4c622e1b 39 };
bogdanm 19:398f4c622e1b 40
bogdanm 19:398f4c622e1b 41 #define ADC_RANGE ADC_10BIT_RANGE
bogdanm 19:398f4c622e1b 42
bogdanm 19:398f4c622e1b 43 void analogin_init(analogin_t *obj, PinName pin) {
bogdanm 19:398f4c622e1b 44 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
bogdanm 19:398f4c622e1b 45 if (obj->adc == (uint32_t)NC) {
bogdanm 19:398f4c622e1b 46 error("ADC pin mapping failed");
bogdanm 19:398f4c622e1b 47 }
bogdanm 19:398f4c622e1b 48
bogdanm 19:398f4c622e1b 49 // Power up ADC
bogdanm 19:398f4c622e1b 50 LPC_SYSCON->PDRUNCFG &= ~ (1 << 4);
bogdanm 19:398f4c622e1b 51 LPC_SYSCON->SYSAHBCLKCTRL |= ((uint32_t)1 << 13);
bogdanm 19:398f4c622e1b 52
bogdanm 19:398f4c622e1b 53 uint32_t offset = (uint32_t)pin & 0xff;
bogdanm 19:398f4c622e1b 54 __IO uint32_t *reg = (__IO uint32_t*)(LPC_IOCON_BASE + offset);
bogdanm 19:398f4c622e1b 55
bogdanm 19:398f4c622e1b 56 // set pin to ADC mode
bogdanm 19:398f4c622e1b 57 *reg &= ~(1 << 7); // set ADMODE = 0 (analog mode)
bogdanm 19:398f4c622e1b 58
bogdanm 19:398f4c622e1b 59 uint32_t PCLK = SystemCoreClock;
bogdanm 19:398f4c622e1b 60 uint32_t MAX_ADC_CLK = 4500000;
bogdanm 19:398f4c622e1b 61 uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
bogdanm 19:398f4c622e1b 62
bogdanm 19:398f4c622e1b 63 LPC_ADC->CR = (0 << 0) // no channels selected
bogdanm 19:398f4c622e1b 64 | (clkdiv << 8) // max of 4.5MHz
bogdanm 19:398f4c622e1b 65 | (0 << 16) // BURST = 0, software controlled
bogdanm 19:398f4c622e1b 66 | ( 0 << 17 ); // CLKS = 0, not applicable
bogdanm 19:398f4c622e1b 67
bogdanm 19:398f4c622e1b 68 pinmap_pinout(pin, PinMap_ADC);
bogdanm 19:398f4c622e1b 69 }
bogdanm 19:398f4c622e1b 70
bogdanm 19:398f4c622e1b 71 static inline uint32_t adc_read(analogin_t *obj) {
bogdanm 19:398f4c622e1b 72 // Select the appropriate channel and start conversion
bogdanm 19:398f4c622e1b 73 LPC_ADC->CR &= ~0xFF;
bogdanm 19:398f4c622e1b 74 LPC_ADC->CR |= 1 << (int)obj->adc;
bogdanm 19:398f4c622e1b 75 LPC_ADC->CR |= 1 << 24;
bogdanm 19:398f4c622e1b 76
bogdanm 19:398f4c622e1b 77 // Repeatedly get the sample data until DONE bit
bogdanm 19:398f4c622e1b 78 unsigned int data;
bogdanm 19:398f4c622e1b 79 do {
bogdanm 19:398f4c622e1b 80 data = LPC_ADC->GDR;
bogdanm 19:398f4c622e1b 81 } while ((data & ((unsigned int)1 << 31)) == 0);
bogdanm 19:398f4c622e1b 82
bogdanm 19:398f4c622e1b 83 // Stop conversion
bogdanm 19:398f4c622e1b 84 LPC_ADC->CR &= ~(1 << 24);
bogdanm 19:398f4c622e1b 85
bogdanm 19:398f4c622e1b 86 return (data >> 6) & ADC_RANGE; // 10 bit
bogdanm 19:398f4c622e1b 87 }
bogdanm 19:398f4c622e1b 88
bogdanm 19:398f4c622e1b 89 static inline void order(uint32_t *a, uint32_t *b) {
bogdanm 19:398f4c622e1b 90 if (*a > *b) {
bogdanm 19:398f4c622e1b 91 uint32_t t = *a;
bogdanm 19:398f4c622e1b 92 *a = *b;
bogdanm 19:398f4c622e1b 93 *b = t;
bogdanm 19:398f4c622e1b 94 }
bogdanm 19:398f4c622e1b 95 }
bogdanm 19:398f4c622e1b 96
bogdanm 19:398f4c622e1b 97 static inline uint32_t adc_read_u32(analogin_t *obj) {
bogdanm 19:398f4c622e1b 98 uint32_t value;
bogdanm 19:398f4c622e1b 99 #if ANALOGIN_MEDIAN_FILTER
bogdanm 19:398f4c622e1b 100 uint32_t v1 = adc_read(obj);
bogdanm 19:398f4c622e1b 101 uint32_t v2 = adc_read(obj);
bogdanm 19:398f4c622e1b 102 uint32_t v3 = adc_read(obj);
bogdanm 19:398f4c622e1b 103 order(&v1, &v2);
bogdanm 19:398f4c622e1b 104 order(&v2, &v3);
bogdanm 19:398f4c622e1b 105 order(&v1, &v2);
bogdanm 19:398f4c622e1b 106 value = v2;
bogdanm 19:398f4c622e1b 107 #else
bogdanm 19:398f4c622e1b 108 value = adc_read(obj);
bogdanm 19:398f4c622e1b 109 #endif
bogdanm 19:398f4c622e1b 110 return value;
bogdanm 19:398f4c622e1b 111 }
bogdanm 19:398f4c622e1b 112
bogdanm 19:398f4c622e1b 113 uint16_t analogin_read_u16(analogin_t *obj) {
bogdanm 19:398f4c622e1b 114 uint32_t value = adc_read_u32(obj);
bogdanm 19:398f4c622e1b 115
bogdanm 19:398f4c622e1b 116 return (value << 6) | ((value >> 4) & 0x003F); // 10 bit
bogdanm 19:398f4c622e1b 117 }
bogdanm 19:398f4c622e1b 118
bogdanm 19:398f4c622e1b 119 float analogin_read(analogin_t *obj) {
bogdanm 19:398f4c622e1b 120 uint32_t value = adc_read_u32(obj);
bogdanm 19:398f4c622e1b 121 return (float)value * (1.0f / (float)ADC_RANGE);
bogdanm 19:398f4c622e1b 122 }