shinichi nakazawa / mbed-src

mbed library sources

Dependents:   Nucleo_blink_led

Fork of mbed-src by mbed official

targets/hal/TARGET_NXP/TARGET_LPC408X/TARGET_LPC4088/analogin_api.c@462:e03396e14338, 2015-02-03 (annotated)

Committer:
mbed_official
Date:
Tue Feb 03 13:15:07 2015 +0000
Revision:
462:e03396e14338
Synchronized with git revision ae7e2e76ed57b9ca11dc05f51f097df1de144fe2



Full URL: https://github.com/mbedmicro/mbed/commit/ae7e2e76ed57b9ca11dc05f51f097df1de144fe2/



Add support for EA LPC4088_DM

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 462:e03396e14338 1 /* mbed Microcontroller Library
mbed_official 462:e03396e14338 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 462:e03396e14338 3 *
mbed_official 462:e03396e14338 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 462:e03396e14338 5 * you may not use this file except in compliance with the License.
mbed_official 462:e03396e14338 6 * You may obtain a copy of the License at
mbed_official 462:e03396e14338 7 *
mbed_official 462:e03396e14338 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 462:e03396e14338 9 *
mbed_official 462:e03396e14338 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 462:e03396e14338 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 462:e03396e14338 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 462:e03396e14338 13 * See the License for the specific language governing permissions and
mbed_official 462:e03396e14338 14 * limitations under the License.
mbed_official 462:e03396e14338 15 */
mbed_official 462:e03396e14338 16 #include "mbed_assert.h"
mbed_official 462:e03396e14338 17 #include "analogin_api.h"
mbed_official 462:e03396e14338 18 #include "cmsis.h"
mbed_official 462:e03396e14338 19 #include "pinmap.h"
mbed_official 462:e03396e14338 20 #include "mbed_error.h"
mbed_official 462:e03396e14338 21
mbed_official 462:e03396e14338 22 #define ANALOGIN_MEDIAN_FILTER 1
mbed_official 462:e03396e14338 23
mbed_official 462:e03396e14338 24 #define ADC_10BIT_RANGE 0x3FF
mbed_official 462:e03396e14338 25 #define ADC_12BIT_RANGE 0xFFF
mbed_official 462:e03396e14338 26
mbed_official 462:e03396e14338 27 static inline int div_round_up(int x, int y) {
mbed_official 462:e03396e14338 28 return (x + (y - 1)) / y;
mbed_official 462:e03396e14338 29 }
mbed_official 462:e03396e14338 30
mbed_official 462:e03396e14338 31 static const PinMap PinMap_ADC[] = {
mbed_official 462:e03396e14338 32 {P0_23, ADC0_0, 0x01},
mbed_official 462:e03396e14338 33 {P0_24, ADC0_1, 0x01},
mbed_official 462:e03396e14338 34 {P0_25, ADC0_2, 0x01},
mbed_official 462:e03396e14338 35 {P0_26, ADC0_3, 0x01},
mbed_official 462:e03396e14338 36 {P1_30, ADC0_4, 0x03},
mbed_official 462:e03396e14338 37 {P1_31, ADC0_5, 0x03},
mbed_official 462:e03396e14338 38 {P0_12, ADC0_6, 0x03},
mbed_official 462:e03396e14338 39 {P0_13, ADC0_7, 0x03},
mbed_official 462:e03396e14338 40 {NC , NC , 0 }
mbed_official 462:e03396e14338 41 };
mbed_official 462:e03396e14338 42
mbed_official 462:e03396e14338 43 #define ADC_RANGE ADC_12BIT_RANGE
mbed_official 462:e03396e14338 44
mbed_official 462:e03396e14338 45 void analogin_init(analogin_t *obj, PinName pin) {
mbed_official 462:e03396e14338 46 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
mbed_official 462:e03396e14338 47 MBED_ASSERT(obj->adc != (ADCName)NC);
mbed_official 462:e03396e14338 48
mbed_official 462:e03396e14338 49 // ensure power is turned on
mbed_official 462:e03396e14338 50 LPC_SC->PCONP |= (1 << 12);
mbed_official 462:e03396e14338 51
mbed_official 462:e03396e14338 52 uint32_t PCLK = PeripheralClock;
mbed_official 462:e03396e14338 53
mbed_official 462:e03396e14338 54 // calculate minimum clock divider
mbed_official 462:e03396e14338 55 // clkdiv = divider - 1
mbed_official 462:e03396e14338 56 uint32_t MAX_ADC_CLK = 12400000;
mbed_official 462:e03396e14338 57 uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
mbed_official 462:e03396e14338 58
mbed_official 462:e03396e14338 59 // Set the generic software-controlled ADC settings
mbed_official 462:e03396e14338 60 LPC_ADC->CR = (0 << 0) // SEL: 0 = no channels selected
mbed_official 462:e03396e14338 61 | (clkdiv << 8) // CLKDIV:
mbed_official 462:e03396e14338 62 | (0 << 16) // BURST: 0 = software control
mbed_official 462:e03396e14338 63 | (1 << 21) // PDN: 1 = operational
mbed_official 462:e03396e14338 64 | (0 << 24) // START: 0 = no start
mbed_official 462:e03396e14338 65 | (0 << 27); // EDGE: not applicable
mbed_official 462:e03396e14338 66
mbed_official 462:e03396e14338 67 // must enable analog mode (ADMODE = 0)
mbed_official 462:e03396e14338 68 __IO uint32_t *reg = (__IO uint32_t*) (LPC_IOCON_BASE + 4 * pin);
mbed_official 462:e03396e14338 69 *reg &= ~(1 << 7);
mbed_official 462:e03396e14338 70
mbed_official 462:e03396e14338 71 pinmap_pinout(pin, PinMap_ADC);
mbed_official 462:e03396e14338 72 }
mbed_official 462:e03396e14338 73
mbed_official 462:e03396e14338 74 static inline uint32_t adc_read(analogin_t *obj) {
mbed_official 462:e03396e14338 75 // Select the appropriate channel and start conversion
mbed_official 462:e03396e14338 76 LPC_ADC->CR &= ~0xFF;
mbed_official 462:e03396e14338 77 LPC_ADC->CR |= 1 << (int)obj->adc;
mbed_official 462:e03396e14338 78 LPC_ADC->CR |= 1 << 24;
mbed_official 462:e03396e14338 79
mbed_official 462:e03396e14338 80 // Repeatedly get the sample data until DONE bit
mbed_official 462:e03396e14338 81 unsigned int data;
mbed_official 462:e03396e14338 82 do {
mbed_official 462:e03396e14338 83 data = LPC_ADC->GDR;
mbed_official 462:e03396e14338 84 } while ((data & ((unsigned int)1 << 31)) == 0);
mbed_official 462:e03396e14338 85
mbed_official 462:e03396e14338 86 // Stop conversion
mbed_official 462:e03396e14338 87 LPC_ADC->CR &= ~(1 << 24);
mbed_official 462:e03396e14338 88
mbed_official 462:e03396e14338 89 return (data >> 4) & ADC_RANGE; // 12 bit
mbed_official 462:e03396e14338 90 }
mbed_official 462:e03396e14338 91
mbed_official 462:e03396e14338 92 static inline void order(uint32_t *a, uint32_t *b) {
mbed_official 462:e03396e14338 93 if (*a > *b) {
mbed_official 462:e03396e14338 94 uint32_t t = *a;
mbed_official 462:e03396e14338 95 *a = *b;
mbed_official 462:e03396e14338 96 *b = t;
mbed_official 462:e03396e14338 97 }
mbed_official 462:e03396e14338 98 }
mbed_official 462:e03396e14338 99
mbed_official 462:e03396e14338 100 static inline uint32_t adc_read_u32(analogin_t *obj) {
mbed_official 462:e03396e14338 101 uint32_t value;
mbed_official 462:e03396e14338 102 #if ANALOGIN_MEDIAN_FILTER
mbed_official 462:e03396e14338 103 uint32_t v1 = adc_read(obj);
mbed_official 462:e03396e14338 104 uint32_t v2 = adc_read(obj);
mbed_official 462:e03396e14338 105 uint32_t v3 = adc_read(obj);
mbed_official 462:e03396e14338 106 order(&v1, &v2);
mbed_official 462:e03396e14338 107 order(&v2, &v3);
mbed_official 462:e03396e14338 108 order(&v1, &v2);
mbed_official 462:e03396e14338 109 value = v2;
mbed_official 462:e03396e14338 110 #else
mbed_official 462:e03396e14338 111 value = adc_read(obj);
mbed_official 462:e03396e14338 112 #endif
mbed_official 462:e03396e14338 113 return value;
mbed_official 462:e03396e14338 114 }
mbed_official 462:e03396e14338 115
mbed_official 462:e03396e14338 116 uint16_t analogin_read_u16(analogin_t *obj) {
mbed_official 462:e03396e14338 117 uint32_t value = adc_read_u32(obj);
mbed_official 462:e03396e14338 118
mbed_official 462:e03396e14338 119 return (value << 4) | ((value >> 8) & 0x000F); // 12 bit
mbed_official 462:e03396e14338 120 }
mbed_official 462:e03396e14338 121
mbed_official 462:e03396e14338 122 float analogin_read(analogin_t *obj) {
mbed_official 462:e03396e14338 123 uint32_t value = adc_read_u32(obj);
mbed_official 462:e03396e14338 124 return (float)value * (1.0f / (float)ADC_RANGE);
mbed_official 462:e03396e14338 125 }