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mbed SDK library sources

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Development branch of the mbed library sources. This library is kept in synch with the latest changes from the mbed SDK and it is not guaranteed to work.

If you are looking for a stable and tested release, please import one of the official mbed library releases:

Import librarymbed

The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_NXP/TARGET_LPC11XX_11CXX/analogin_api.c@30:91c1d09ada54, 2013-09-25 (annotated)

Committer:
mbed_official
Date:
Wed Sep 25 10:30:04 2013 +0100
Revision:
30:91c1d09ada54
Child:
32:4742f6c694e8
Synchronized with git revision 8f57c1e84759991fa81ede0da2b4aabe8530fa09

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 30:91c1d09ada54 1 /* mbed Microcontroller Library
mbed_official 30:91c1d09ada54 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 30:91c1d09ada54 3 *
mbed_official 30:91c1d09ada54 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 30:91c1d09ada54 5 * you may not use this file except in compliance with the License.
mbed_official 30:91c1d09ada54 6 * You may obtain a copy of the License at
mbed_official 30:91c1d09ada54 7 *
mbed_official 30:91c1d09ada54 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 30:91c1d09ada54 9 *
mbed_official 30:91c1d09ada54 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 30:91c1d09ada54 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 30:91c1d09ada54 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 30:91c1d09ada54 13 * See the License for the specific language governing permissions and
mbed_official 30:91c1d09ada54 14 * limitations under the License.
mbed_official 30:91c1d09ada54 15 */
mbed_official 30:91c1d09ada54 16 #include "analogin_api.h"
mbed_official 30:91c1d09ada54 17 #include "cmsis.h"
mbed_official 30:91c1d09ada54 18 #include "pinmap.h"
mbed_official 30:91c1d09ada54 19 #include "error.h"
mbed_official 30:91c1d09ada54 20
mbed_official 30:91c1d09ada54 21 #include "adc_pinmap.h"
mbed_official 30:91c1d09ada54 22
mbed_official 30:91c1d09ada54 23 #define ANALOGIN_MEDIAN_FILTER 1
mbed_official 30:91c1d09ada54 24
mbed_official 30:91c1d09ada54 25 #define ADC_10BIT_RANGE 0x3FF
mbed_official 30:91c1d09ada54 26 #define ADC_12BIT_RANGE 0xFFF
mbed_official 30:91c1d09ada54 27
mbed_official 30:91c1d09ada54 28 static inline int div_round_up(int x, int y) {
mbed_official 30:91c1d09ada54 29 return (x + (y - 1)) / y;
mbed_official 30:91c1d09ada54 30 }
mbed_official 30:91c1d09ada54 31
mbed_official 30:91c1d09ada54 32 #define ADC_RANGE ADC_10BIT_RANGE
mbed_official 30:91c1d09ada54 33
mbed_official 30:91c1d09ada54 34 void analogin_init(analogin_t *obj, PinName pin) {
mbed_official 30:91c1d09ada54 35 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
mbed_official 30:91c1d09ada54 36 if (obj->adc == (uint32_t)NC) {
mbed_official 30:91c1d09ada54 37 error("ADC pin mapping failed");
mbed_official 30:91c1d09ada54 38 return;
mbed_official 30:91c1d09ada54 39 }
mbed_official 30:91c1d09ada54 40
mbed_official 30:91c1d09ada54 41 // Power up ADC
mbed_official 30:91c1d09ada54 42 LPC_SYSCON->PDRUNCFG &= ~ (1 << 4);
mbed_official 30:91c1d09ada54 43 LPC_SYSCON->SYSAHBCLKCTRL |= ((uint32_t)1 << 13);
mbed_official 30:91c1d09ada54 44
mbed_official 30:91c1d09ada54 45 uint32_t offset = (uint32_t)pin & 0xff;
mbed_official 30:91c1d09ada54 46 __IO uint32_t *reg = (__IO uint32_t*)(LPC_IOCON_BASE + offset);
mbed_official 30:91c1d09ada54 47
mbed_official 30:91c1d09ada54 48 // set pin to ADC mode
mbed_official 30:91c1d09ada54 49 *reg &= ~(1 << 7); // set ADMODE = 0 (analog mode)
mbed_official 30:91c1d09ada54 50
mbed_official 30:91c1d09ada54 51 uint32_t PCLK = SystemCoreClock;
mbed_official 30:91c1d09ada54 52 uint32_t MAX_ADC_CLK = 4500000;
mbed_official 30:91c1d09ada54 53 uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
mbed_official 30:91c1d09ada54 54
mbed_official 30:91c1d09ada54 55 LPC_ADC->CR = (0 << 0) // no channels selected
mbed_official 30:91c1d09ada54 56 | (clkdiv << 8) // max of 4.5MHz
mbed_official 30:91c1d09ada54 57 | (0 << 16) // BURST = 0, software controlled
mbed_official 30:91c1d09ada54 58 | ( 0 << 17 ); // CLKS = 0, not applicable
mbed_official 30:91c1d09ada54 59
mbed_official 30:91c1d09ada54 60 pinmap_pinout(pin, PinMap_ADC);
mbed_official 30:91c1d09ada54 61 }
mbed_official 30:91c1d09ada54 62
mbed_official 30:91c1d09ada54 63 static inline uint32_t adc_read(analogin_t *obj) {
mbed_official 30:91c1d09ada54 64 // Select the appropriate channel and start conversion
mbed_official 30:91c1d09ada54 65 LPC_ADC->CR &= ~0xFF;
mbed_official 30:91c1d09ada54 66 LPC_ADC->CR |= 1 << (int)obj->adc;
mbed_official 30:91c1d09ada54 67 LPC_ADC->CR |= 1 << 24;
mbed_official 30:91c1d09ada54 68
mbed_official 30:91c1d09ada54 69 // Repeatedly get the sample data until DONE bit
mbed_official 30:91c1d09ada54 70 unsigned int data;
mbed_official 30:91c1d09ada54 71 do {
mbed_official 30:91c1d09ada54 72 data = LPC_ADC->GDR;
mbed_official 30:91c1d09ada54 73 } while ((data & ((unsigned int)1 << 31)) == 0);
mbed_official 30:91c1d09ada54 74
mbed_official 30:91c1d09ada54 75 // Stop conversion
mbed_official 30:91c1d09ada54 76 LPC_ADC->CR &= ~(1 << 24);
mbed_official 30:91c1d09ada54 77
mbed_official 30:91c1d09ada54 78 return (data >> 6) & ADC_RANGE; // 10 bit
mbed_official 30:91c1d09ada54 79 }
mbed_official 30:91c1d09ada54 80
mbed_official 30:91c1d09ada54 81 static inline void order(uint32_t *a, uint32_t *b) {
mbed_official 30:91c1d09ada54 82 if (*a > *b) {
mbed_official 30:91c1d09ada54 83 uint32_t t = *a;
mbed_official 30:91c1d09ada54 84 *a = *b;
mbed_official 30:91c1d09ada54 85 *b = t;
mbed_official 30:91c1d09ada54 86 }
mbed_official 30:91c1d09ada54 87 }
mbed_official 30:91c1d09ada54 88
mbed_official 30:91c1d09ada54 89 static inline uint32_t adc_read_u32(analogin_t *obj) {
mbed_official 30:91c1d09ada54 90 uint32_t value;
mbed_official 30:91c1d09ada54 91 #if ANALOGIN_MEDIAN_FILTER
mbed_official 30:91c1d09ada54 92 uint32_t v1 = adc_read(obj);
mbed_official 30:91c1d09ada54 93 uint32_t v2 = adc_read(obj);
mbed_official 30:91c1d09ada54 94 uint32_t v3 = adc_read(obj);
mbed_official 30:91c1d09ada54 95 order(&v1, &v2);
mbed_official 30:91c1d09ada54 96 order(&v2, &v3);
mbed_official 30:91c1d09ada54 97 order(&v1, &v2);
mbed_official 30:91c1d09ada54 98 value = v2;
mbed_official 30:91c1d09ada54 99 #else
mbed_official 30:91c1d09ada54 100 value = adc_read(obj);
mbed_official 30:91c1d09ada54 101 #endif
mbed_official 30:91c1d09ada54 102 return value;
mbed_official 30:91c1d09ada54 103 }
mbed_official 30:91c1d09ada54 104
mbed_official 30:91c1d09ada54 105 uint16_t analogin_read_u16(analogin_t *obj) {
mbed_official 30:91c1d09ada54 106 uint32_t value = adc_read_u32(obj);
mbed_official 30:91c1d09ada54 107
mbed_official 30:91c1d09ada54 108 return (value << 6) | ((value >> 4) & 0x003F); // 10 bit
mbed_official 30:91c1d09ada54 109 }
mbed_official 30:91c1d09ada54 110
mbed_official 30:91c1d09ada54 111 float analogin_read(analogin_t *obj) {
mbed_official 30:91c1d09ada54 112 uint32_t value = adc_read_u32(obj);
mbed_official 30:91c1d09ada54 113 return (float)value * (1.0f / (float)ADC_RANGE);
mbed_official 30:91c1d09ada54 114 }