mbed official / mbed-src

mbed library sources

Dependents:   Encrypted my_mbed lklk CyaSSL_DTLS_Cellular ... more

Superseded

This library was superseded by mbed-dev - https://os.mbed.com/users/mbed_official/code/mbed-dev/.

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_LPC2460/analogin_api.c@621:9c82b0f79f3d, 2015-09-11 (annotated)

Committer:
mbed_official
Date:
Fri Sep 11 09:30:09 2015 +0100
Revision:
621:9c82b0f79f3d
Parent:
554:edd95c0879f8 
Synchronized with git revision 6c1d63e069ab9bd86de92e8296ca783681257538



Full URL: https://github.com/mbedmicro/mbed/commit/6c1d63e069ab9bd86de92e8296ca783681257538/



ignore target files not supported by the yotta module

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 554:edd95c0879f8 1 /* mbed Microcontroller Library
mbed_official 554:edd95c0879f8 2 * Copyright (c) 2006-2015 ARM Limited
mbed_official 554:edd95c0879f8 3 *
mbed_official 554:edd95c0879f8 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 554:edd95c0879f8 5 * you may not use this file except in compliance with the License.
mbed_official 554:edd95c0879f8 6 * You may obtain a copy of the License at
mbed_official 554:edd95c0879f8 7 *
mbed_official 554:edd95c0879f8 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 554:edd95c0879f8 9 *
mbed_official 554:edd95c0879f8 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 554:edd95c0879f8 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 554:edd95c0879f8 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 554:edd95c0879f8 13 * See the License for the specific language governing permissions and
mbed_official 554:edd95c0879f8 14 * limitations under the License.
mbed_official 554:edd95c0879f8 15 */
mbed_official 554:edd95c0879f8 16 #include "mbed_assert.h"
mbed_official 554:edd95c0879f8 17 #include "analogin_api.h"
mbed_official 554:edd95c0879f8 18 #include "cmsis.h"
mbed_official 554:edd95c0879f8 19 #include "pinmap.h"
mbed_official 554:edd95c0879f8 20
mbed_official 554:edd95c0879f8 21 #define ANALOGIN_MEDIAN_FILTER 1
mbed_official 554:edd95c0879f8 22
mbed_official 554:edd95c0879f8 23 #define ADC_10BIT_RANGE 0x3FF
mbed_official 554:edd95c0879f8 24 #define ADC_12BIT_RANGE 0xFFF
mbed_official 554:edd95c0879f8 25
mbed_official 554:edd95c0879f8 26 static inline int div_round_up(int x, int y) {
mbed_official 554:edd95c0879f8 27 return (x + (y - 1)) / y;
mbed_official 554:edd95c0879f8 28 }
mbed_official 554:edd95c0879f8 29
mbed_official 554:edd95c0879f8 30 static const PinMap PinMap_ADC[] = {
mbed_official 554:edd95c0879f8 31 {P0_23, ADC0_0, 1},
mbed_official 554:edd95c0879f8 32 {P0_24, ADC0_1, 1},
mbed_official 554:edd95c0879f8 33 {P0_25, ADC0_2, 1},
mbed_official 554:edd95c0879f8 34 {P0_26, ADC0_3, 1},
mbed_official 554:edd95c0879f8 35 {P1_30, ADC0_4, 3},
mbed_official 554:edd95c0879f8 36 {P1_31, ADC0_5, 3},
mbed_official 554:edd95c0879f8 37 {P0_12, ADC0_6, 3},
mbed_official 554:edd95c0879f8 38 {P0_13, ADC0_7, 3},
mbed_official 554:edd95c0879f8 39 {NC, NC, 0}
mbed_official 554:edd95c0879f8 40 };
mbed_official 554:edd95c0879f8 41
mbed_official 554:edd95c0879f8 42 #define ADC_RANGE ADC_10BIT_RANGE
mbed_official 554:edd95c0879f8 43
mbed_official 554:edd95c0879f8 44
mbed_official 554:edd95c0879f8 45 void analogin_init(analogin_t *obj, PinName pin) {
mbed_official 554:edd95c0879f8 46 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
mbed_official 554:edd95c0879f8 47 MBED_ASSERT(obj->adc != (ADCName)NC);
mbed_official 554:edd95c0879f8 48
mbed_official 554:edd95c0879f8 49 // ensure power is turned on
mbed_official 554:edd95c0879f8 50 LPC_SC->PCONP |= (1 << PCADC);
mbed_official 554:edd95c0879f8 51
mbed_official 554:edd95c0879f8 52 // set PCLK of ADC to /1
mbed_official 554:edd95c0879f8 53 LPC_SC->PCLKSEL0 &= ~(0x3 << 24);
mbed_official 554:edd95c0879f8 54 LPC_SC->PCLKSEL0 |= (0x1 << 24);
mbed_official 554:edd95c0879f8 55 uint32_t PCLK = SystemCoreClock;
mbed_official 554:edd95c0879f8 56
mbed_official 554:edd95c0879f8 57 // calculate minimum clock divider
mbed_official 554:edd95c0879f8 58 // clkdiv = divider - 1
mbed_official 554:edd95c0879f8 59 uint32_t MAX_ADC_CLK = 4500000;
mbed_official 554:edd95c0879f8 60 uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
mbed_official 554:edd95c0879f8 61
mbed_official 554:edd95c0879f8 62 // Set the generic software-controlled ADC settings
mbed_official 554:edd95c0879f8 63 LPC_ADC->ADCR = (0 << 0) // SEL: 0 = no channels selected
mbed_official 554:edd95c0879f8 64 | (clkdiv << 8) // CLKDIV: PCLK max ~= 25MHz, /25 to give safe 1MHz at fastest
mbed_official 554:edd95c0879f8 65 | (0 << 16) // BURST: 0 = software control
mbed_official 554:edd95c0879f8 66 | (0 << 17) // CLKS: not applicable
mbed_official 554:edd95c0879f8 67 | (1 << 21) // PDN: 1 = operational
mbed_official 554:edd95c0879f8 68 | (0 << 24) // START: 0 = no start
mbed_official 554:edd95c0879f8 69 | (0 << 27); // EDGE: not applicable
mbed_official 554:edd95c0879f8 70
mbed_official 554:edd95c0879f8 71 pinmap_pinout(pin, PinMap_ADC);
mbed_official 554:edd95c0879f8 72 }
mbed_official 554:edd95c0879f8 73
mbed_official 554:edd95c0879f8 74 static inline uint32_t adc_read(analogin_t *obj) {
mbed_official 554:edd95c0879f8 75 // Select the appropriate channel and start conversion
mbed_official 554:edd95c0879f8 76 LPC_ADC->ADCR &= ~0xFF;
mbed_official 554:edd95c0879f8 77 LPC_ADC->ADCR |= 1 << (int)obj->adc;
mbed_official 554:edd95c0879f8 78 LPC_ADC->ADCR |= 1 << 24;
mbed_official 554:edd95c0879f8 79
mbed_official 554:edd95c0879f8 80 // Repeatedly get the sample data until DONE bit
mbed_official 554:edd95c0879f8 81 unsigned int data;
mbed_official 554:edd95c0879f8 82 do {
mbed_official 554:edd95c0879f8 83 data = LPC_ADC->ADGDR;
mbed_official 554:edd95c0879f8 84 } while ((data & ((unsigned int)1 << 31)) == 0);
mbed_official 554:edd95c0879f8 85
mbed_official 554:edd95c0879f8 86 // Stop conversion
mbed_official 554:edd95c0879f8 87 LPC_ADC->ADCR &= ~(1 << 24);
mbed_official 554:edd95c0879f8 88
mbed_official 554:edd95c0879f8 89 return (data >> 6) & ADC_RANGE; // 10 bit
mbed_official 554:edd95c0879f8 90 }
mbed_official 554:edd95c0879f8 91
mbed_official 554:edd95c0879f8 92 static inline void order(uint32_t *a, uint32_t *b) {
mbed_official 554:edd95c0879f8 93 if (*a > *b) {
mbed_official 554:edd95c0879f8 94 uint32_t t = *a;
mbed_official 554:edd95c0879f8 95 *a = *b;
mbed_official 554:edd95c0879f8 96 *b = t;
mbed_official 554:edd95c0879f8 97 }
mbed_official 554:edd95c0879f8 98 }
mbed_official 554:edd95c0879f8 99
mbed_official 554:edd95c0879f8 100 static inline uint32_t adc_read_u32(analogin_t *obj) {
mbed_official 554:edd95c0879f8 101 uint32_t value;
mbed_official 554:edd95c0879f8 102 #if ANALOGIN_MEDIAN_FILTER
mbed_official 554:edd95c0879f8 103 uint32_t v1 = adc_read(obj);
mbed_official 554:edd95c0879f8 104 uint32_t v2 = adc_read(obj);
mbed_official 554:edd95c0879f8 105 uint32_t v3 = adc_read(obj);
mbed_official 554:edd95c0879f8 106 order(&v1, &v2);
mbed_official 554:edd95c0879f8 107 order(&v2, &v3);
mbed_official 554:edd95c0879f8 108 order(&v1, &v2);
mbed_official 554:edd95c0879f8 109 value = v2;
mbed_official 554:edd95c0879f8 110 #else
mbed_official 554:edd95c0879f8 111 value = adc_read(obj);
mbed_official 554:edd95c0879f8 112 #endif
mbed_official 554:edd95c0879f8 113 return value;
mbed_official 554:edd95c0879f8 114 }
mbed_official 554:edd95c0879f8 115
mbed_official 554:edd95c0879f8 116 uint16_t analogin_read_u16(analogin_t *obj) {
mbed_official 554:edd95c0879f8 117 uint32_t value = adc_read_u32(obj);
mbed_official 554:edd95c0879f8 118
mbed_official 554:edd95c0879f8 119 return (value << 6) | ((value >> 4) & 0x003F); // 10 bit
mbed_official 554:edd95c0879f8 120 }
mbed_official 554:edd95c0879f8 121
mbed_official 554:edd95c0879f8 122 float analogin_read(analogin_t *obj) {
mbed_official 554:edd95c0879f8 123 uint32_t value = adc_read_u32(obj);
mbed_official 554:edd95c0879f8 124 return (float)value * (1.0f / (float)ADC_RANGE);
mbed_official 554:edd95c0879f8 125 }