MacroRat / MouseCode

Mouse code for the MacroRat

Dependencies:   ITG3200 QEI

mbed-dev/targets/TARGET_NXP/TARGET_LPC11XX_11CXX/analogin_api.c@18:6a4db94011d3, 2017-05-14 (annotated)

Committer:
sahilmgandhi
Date:
Sun May 14 23:18:57 2017 +0000
Revision:
18:6a4db94011d3
Publishing again

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sahilmgandhi 18:6a4db94011d3 1 /* mbed Microcontroller Library
sahilmgandhi 18:6a4db94011d3 2 * Copyright (c) 2006-2013 ARM Limited
sahilmgandhi 18:6a4db94011d3 3 *
sahilmgandhi 18:6a4db94011d3 4 * Licensed under the Apache License, Version 2.0 (the "License");
sahilmgandhi 18:6a4db94011d3 5 * you may not use this file except in compliance with the License.
sahilmgandhi 18:6a4db94011d3 6 * You may obtain a copy of the License at
sahilmgandhi 18:6a4db94011d3 7 *
sahilmgandhi 18:6a4db94011d3 8 * http://www.apache.org/licenses/LICENSE-2.0
sahilmgandhi 18:6a4db94011d3 9 *
sahilmgandhi 18:6a4db94011d3 10 * Unless required by applicable law or agreed to in writing, software
sahilmgandhi 18:6a4db94011d3 11 * distributed under the License is distributed on an "AS IS" BASIS,
sahilmgandhi 18:6a4db94011d3 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
sahilmgandhi 18:6a4db94011d3 13 * See the License for the specific language governing permissions and
sahilmgandhi 18:6a4db94011d3 14 * limitations under the License.
sahilmgandhi 18:6a4db94011d3 15 */
sahilmgandhi 18:6a4db94011d3 16 #include "mbed_assert.h"
sahilmgandhi 18:6a4db94011d3 17 #include "analogin_api.h"
sahilmgandhi 18:6a4db94011d3 18 #include "cmsis.h"
sahilmgandhi 18:6a4db94011d3 19 #include "pinmap.h"
sahilmgandhi 18:6a4db94011d3 20 #include "mbed_error.h"
sahilmgandhi 18:6a4db94011d3 21
sahilmgandhi 18:6a4db94011d3 22 static const PinMap PinMap_ADC[] = {
sahilmgandhi 18:6a4db94011d3 23 {P0_11, ADC0_0, 2},
sahilmgandhi 18:6a4db94011d3 24 {P1_0 , ADC0_1, 2},
sahilmgandhi 18:6a4db94011d3 25 {P1_1 , ADC0_2, 2},
sahilmgandhi 18:6a4db94011d3 26 {P1_2 , ADC0_3, 2},
sahilmgandhi 18:6a4db94011d3 27 // {P1_3 , ADC0_4, 2}, -- should be mapped to SWDIO only
sahilmgandhi 18:6a4db94011d3 28 {P1_4 , ADC0_5, 1},
sahilmgandhi 18:6a4db94011d3 29 {P1_10, ADC0_6, 1},
sahilmgandhi 18:6a4db94011d3 30 {P1_11, ADC0_7, 1},
sahilmgandhi 18:6a4db94011d3 31 {NC , NC , 0}
sahilmgandhi 18:6a4db94011d3 32 };
sahilmgandhi 18:6a4db94011d3 33
sahilmgandhi 18:6a4db94011d3 34 #define ANALOGIN_MEDIAN_FILTER 1
sahilmgandhi 18:6a4db94011d3 35
sahilmgandhi 18:6a4db94011d3 36 #define ADC_10BIT_RANGE 0x3FF
sahilmgandhi 18:6a4db94011d3 37 #define ADC_12BIT_RANGE 0xFFF
sahilmgandhi 18:6a4db94011d3 38
sahilmgandhi 18:6a4db94011d3 39 static inline int div_round_up(int x, int y) {
sahilmgandhi 18:6a4db94011d3 40 return (x + (y - 1)) / y;
sahilmgandhi 18:6a4db94011d3 41 }
sahilmgandhi 18:6a4db94011d3 42
sahilmgandhi 18:6a4db94011d3 43 #define ADC_RANGE ADC_10BIT_RANGE
sahilmgandhi 18:6a4db94011d3 44
sahilmgandhi 18:6a4db94011d3 45 void analogin_init(analogin_t *obj, PinName pin) {
sahilmgandhi 18:6a4db94011d3 46 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
sahilmgandhi 18:6a4db94011d3 47 MBED_ASSERT(obj->adc != (ADCName)NC);
sahilmgandhi 18:6a4db94011d3 48
sahilmgandhi 18:6a4db94011d3 49 // Power up ADC
sahilmgandhi 18:6a4db94011d3 50 LPC_SYSCON->PDRUNCFG &= ~ (1 << 4);
sahilmgandhi 18:6a4db94011d3 51 LPC_SYSCON->SYSAHBCLKCTRL |= ((uint32_t)1 << 13);
sahilmgandhi 18:6a4db94011d3 52
sahilmgandhi 18:6a4db94011d3 53 uint32_t offset = (uint32_t)pin & 0xff;
sahilmgandhi 18:6a4db94011d3 54 __IO uint32_t *reg = (__IO uint32_t*)(LPC_IOCON_BASE + offset);
sahilmgandhi 18:6a4db94011d3 55
sahilmgandhi 18:6a4db94011d3 56 // set pin to ADC mode
sahilmgandhi 18:6a4db94011d3 57 *reg &= ~(1 << 7); // set ADMODE = 0 (analog mode)
sahilmgandhi 18:6a4db94011d3 58
sahilmgandhi 18:6a4db94011d3 59 uint32_t PCLK = SystemCoreClock;
sahilmgandhi 18:6a4db94011d3 60 uint32_t MAX_ADC_CLK = 4500000;
sahilmgandhi 18:6a4db94011d3 61 uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
sahilmgandhi 18:6a4db94011d3 62
sahilmgandhi 18:6a4db94011d3 63 LPC_ADC->CR = (0 << 0) // no channels selected
sahilmgandhi 18:6a4db94011d3 64 | (clkdiv << 8) // max of 4.5MHz
sahilmgandhi 18:6a4db94011d3 65 | (0 << 16) // BURST = 0, software controlled
sahilmgandhi 18:6a4db94011d3 66 | ( 0 << 17 ); // CLKS = 0, not applicable
sahilmgandhi 18:6a4db94011d3 67
sahilmgandhi 18:6a4db94011d3 68 pinmap_pinout(pin, PinMap_ADC);
sahilmgandhi 18:6a4db94011d3 69 }
sahilmgandhi 18:6a4db94011d3 70
sahilmgandhi 18:6a4db94011d3 71 static inline uint32_t adc_read(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 72 // Select the appropriate channel and start conversion
sahilmgandhi 18:6a4db94011d3 73 LPC_ADC->CR &= ~0xFF;
sahilmgandhi 18:6a4db94011d3 74 LPC_ADC->CR |= 1 << (int)obj->adc;
sahilmgandhi 18:6a4db94011d3 75 LPC_ADC->CR |= 1 << 24;
sahilmgandhi 18:6a4db94011d3 76
sahilmgandhi 18:6a4db94011d3 77 // Repeatedly get the sample data until DONE bit
sahilmgandhi 18:6a4db94011d3 78 unsigned int data;
sahilmgandhi 18:6a4db94011d3 79 do {
sahilmgandhi 18:6a4db94011d3 80 data = LPC_ADC->GDR;
sahilmgandhi 18:6a4db94011d3 81 } while ((data & ((unsigned int)1 << 31)) == 0);
sahilmgandhi 18:6a4db94011d3 82
sahilmgandhi 18:6a4db94011d3 83 // Stop conversion
sahilmgandhi 18:6a4db94011d3 84 LPC_ADC->CR &= ~(1 << 24);
sahilmgandhi 18:6a4db94011d3 85
sahilmgandhi 18:6a4db94011d3 86 return (data >> 6) & ADC_RANGE; // 10 bit
sahilmgandhi 18:6a4db94011d3 87 }
sahilmgandhi 18:6a4db94011d3 88
sahilmgandhi 18:6a4db94011d3 89 static inline void order(uint32_t *a, uint32_t *b) {
sahilmgandhi 18:6a4db94011d3 90 if (*a > *b) {
sahilmgandhi 18:6a4db94011d3 91 uint32_t t = *a;
sahilmgandhi 18:6a4db94011d3 92 *a = *b;
sahilmgandhi 18:6a4db94011d3 93 *b = t;
sahilmgandhi 18:6a4db94011d3 94 }
sahilmgandhi 18:6a4db94011d3 95 }
sahilmgandhi 18:6a4db94011d3 96
sahilmgandhi 18:6a4db94011d3 97 static inline uint32_t adc_read_u32(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 98 uint32_t value;
sahilmgandhi 18:6a4db94011d3 99 #if ANALOGIN_MEDIAN_FILTER
sahilmgandhi 18:6a4db94011d3 100 uint32_t v1 = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 101 uint32_t v2 = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 102 uint32_t v3 = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 103 order(&v1, &v2);
sahilmgandhi 18:6a4db94011d3 104 order(&v2, &v3);
sahilmgandhi 18:6a4db94011d3 105 order(&v1, &v2);
sahilmgandhi 18:6a4db94011d3 106 value = v2;
sahilmgandhi 18:6a4db94011d3 107 #else
sahilmgandhi 18:6a4db94011d3 108 value = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 109 #endif
sahilmgandhi 18:6a4db94011d3 110 return value;
sahilmgandhi 18:6a4db94011d3 111 }
sahilmgandhi 18:6a4db94011d3 112
sahilmgandhi 18:6a4db94011d3 113 uint16_t analogin_read_u16(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 114 uint32_t value = adc_read_u32(obj);
sahilmgandhi 18:6a4db94011d3 115
sahilmgandhi 18:6a4db94011d3 116 return (value << 6) | ((value >> 4) & 0x003F); // 10 bit
sahilmgandhi 18:6a4db94011d3 117 }
sahilmgandhi 18:6a4db94011d3 118
sahilmgandhi 18:6a4db94011d3 119 float analogin_read(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 120 uint32_t value = adc_read_u32(obj);
sahilmgandhi 18:6a4db94011d3 121 return (float)value * (1.0f / (float)ADC_RANGE);
sahilmgandhi 18:6a4db94011d3 122 }