MacroRat / MouseCode

Mouse code for the MacroRat

Dependencies:   ITG3200 QEI

mbed-dev/targets/TARGET_NXP/TARGET_LPC13XX/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 #define ANALOGIN_MEDIAN_FILTER 1
sahilmgandhi 18:6a4db94011d3 23
sahilmgandhi 18:6a4db94011d3 24 #define ADC_10BIT_RANGE 0x3FF
sahilmgandhi 18:6a4db94011d3 25 #define ADC_12BIT_RANGE 0xFFF
sahilmgandhi 18:6a4db94011d3 26
sahilmgandhi 18:6a4db94011d3 27 static inline int div_round_up(int x, int y) {
sahilmgandhi 18:6a4db94011d3 28 return (x + (y - 1)) / y;
sahilmgandhi 18:6a4db94011d3 29 }
sahilmgandhi 18:6a4db94011d3 30
sahilmgandhi 18:6a4db94011d3 31 static const PinMap PinMap_ADC[] = {
sahilmgandhi 18:6a4db94011d3 32 {P0_11, ADC0_0, 0x02},
sahilmgandhi 18:6a4db94011d3 33 {P0_12, ADC0_1, 0x02},
sahilmgandhi 18:6a4db94011d3 34 {P0_13, ADC0_2, 0x02},
sahilmgandhi 18:6a4db94011d3 35 {P0_14, ADC0_3, 0x02},
sahilmgandhi 18:6a4db94011d3 36 {P0_15, ADC0_4, 0x02},
sahilmgandhi 18:6a4db94011d3 37 {P0_16, ADC0_5, 0x01},
sahilmgandhi 18:6a4db94011d3 38 {P0_22, ADC0_6, 0x01},
sahilmgandhi 18:6a4db94011d3 39 {P0_23, ADC0_7, 0x01},
sahilmgandhi 18:6a4db94011d3 40 {NC , NC , 0 }
sahilmgandhi 18:6a4db94011d3 41 };
sahilmgandhi 18:6a4db94011d3 42
sahilmgandhi 18:6a4db94011d3 43 #define LPC_IOCON0_BASE (LPC_IOCON_BASE)
sahilmgandhi 18:6a4db94011d3 44 #define LPC_IOCON1_BASE (LPC_IOCON_BASE + 0x60)
sahilmgandhi 18:6a4db94011d3 45
sahilmgandhi 18:6a4db94011d3 46 #define ADC_RANGE ADC_10BIT_RANGE
sahilmgandhi 18:6a4db94011d3 47
sahilmgandhi 18:6a4db94011d3 48 void analogin_init(analogin_t *obj, PinName pin) {
sahilmgandhi 18:6a4db94011d3 49 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
sahilmgandhi 18:6a4db94011d3 50 MBED_ASSERT(obj->adc != (ADCName)NC);
sahilmgandhi 18:6a4db94011d3 51
sahilmgandhi 18:6a4db94011d3 52 // Power up ADC
sahilmgandhi 18:6a4db94011d3 53 LPC_SYSCON->PDRUNCFG &= ~ (1 << 4);
sahilmgandhi 18:6a4db94011d3 54 LPC_SYSCON->SYSAHBCLKCTRL |= ((uint32_t)1 << 13);
sahilmgandhi 18:6a4db94011d3 55
sahilmgandhi 18:6a4db94011d3 56 uint32_t pin_number = (uint32_t)pin;
sahilmgandhi 18:6a4db94011d3 57 __IO uint32_t *reg = (pin_number < 32) ? (__IO uint32_t*)(LPC_IOCON0_BASE + 4 * pin_number) : (__IO uint32_t*)(LPC_IOCON1_BASE + 4 * (pin_number - 32));
sahilmgandhi 18:6a4db94011d3 58
sahilmgandhi 18:6a4db94011d3 59 // set pin to ADC mode
sahilmgandhi 18:6a4db94011d3 60 *reg &= ~(1 << 7); // set ADMODE = 0 (analog mode)
sahilmgandhi 18:6a4db94011d3 61
sahilmgandhi 18:6a4db94011d3 62 uint32_t PCLK = SystemCoreClock;
sahilmgandhi 18:6a4db94011d3 63 uint32_t MAX_ADC_CLK = 4500000;
sahilmgandhi 18:6a4db94011d3 64 uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
sahilmgandhi 18:6a4db94011d3 65
sahilmgandhi 18:6a4db94011d3 66 LPC_ADC->CR = (0 << 0) // no channels selected
sahilmgandhi 18:6a4db94011d3 67 | (clkdiv << 8) // max of 4.5MHz
sahilmgandhi 18:6a4db94011d3 68 | (0 << 16) // BURST = 0, software controlled
sahilmgandhi 18:6a4db94011d3 69 | ( 0 << 17 ); // CLKS = 0, not applicable
sahilmgandhi 18:6a4db94011d3 70
sahilmgandhi 18:6a4db94011d3 71 pinmap_pinout(pin, PinMap_ADC);
sahilmgandhi 18:6a4db94011d3 72 }
sahilmgandhi 18:6a4db94011d3 73
sahilmgandhi 18:6a4db94011d3 74 static inline uint32_t adc_read(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 75 // Select the appropriate channel and start conversion
sahilmgandhi 18:6a4db94011d3 76 LPC_ADC->CR &= ~0xFF;
sahilmgandhi 18:6a4db94011d3 77 LPC_ADC->CR |= 1 << (int)obj->adc;
sahilmgandhi 18:6a4db94011d3 78 LPC_ADC->CR |= 1 << 24;
sahilmgandhi 18:6a4db94011d3 79
sahilmgandhi 18:6a4db94011d3 80 // Repeatedly get the sample data until DONE bit
sahilmgandhi 18:6a4db94011d3 81 unsigned int data;
sahilmgandhi 18:6a4db94011d3 82 do {
sahilmgandhi 18:6a4db94011d3 83 data = LPC_ADC->GDR;
sahilmgandhi 18:6a4db94011d3 84 } while ((data & ((unsigned int)1 << 31)) == 0);
sahilmgandhi 18:6a4db94011d3 85
sahilmgandhi 18:6a4db94011d3 86 // Stop conversion
sahilmgandhi 18:6a4db94011d3 87 LPC_ADC->CR &= ~(1 << 24);
sahilmgandhi 18:6a4db94011d3 88
sahilmgandhi 18:6a4db94011d3 89 return (data >> 6) & ADC_RANGE; // 10 bit
sahilmgandhi 18:6a4db94011d3 90 }
sahilmgandhi 18:6a4db94011d3 91
sahilmgandhi 18:6a4db94011d3 92 static inline void order(uint32_t *a, uint32_t *b) {
sahilmgandhi 18:6a4db94011d3 93 if (*a > *b) {
sahilmgandhi 18:6a4db94011d3 94 uint32_t t = *a;
sahilmgandhi 18:6a4db94011d3 95 *a = *b;
sahilmgandhi 18:6a4db94011d3 96 *b = t;
sahilmgandhi 18:6a4db94011d3 97 }
sahilmgandhi 18:6a4db94011d3 98 }
sahilmgandhi 18:6a4db94011d3 99
sahilmgandhi 18:6a4db94011d3 100 static inline uint32_t adc_read_u32(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 101 uint32_t value;
sahilmgandhi 18:6a4db94011d3 102 #if ANALOGIN_MEDIAN_FILTER
sahilmgandhi 18:6a4db94011d3 103 uint32_t v1 = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 104 uint32_t v2 = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 105 uint32_t v3 = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 106 order(&v1, &v2);
sahilmgandhi 18:6a4db94011d3 107 order(&v2, &v3);
sahilmgandhi 18:6a4db94011d3 108 order(&v1, &v2);
sahilmgandhi 18:6a4db94011d3 109 value = v2;
sahilmgandhi 18:6a4db94011d3 110 #else
sahilmgandhi 18:6a4db94011d3 111 value = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 112 #endif
sahilmgandhi 18:6a4db94011d3 113 return value;
sahilmgandhi 18:6a4db94011d3 114 }
sahilmgandhi 18:6a4db94011d3 115
sahilmgandhi 18:6a4db94011d3 116 uint16_t analogin_read_u16(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 117 uint32_t value = adc_read_u32(obj);
sahilmgandhi 18:6a4db94011d3 118
sahilmgandhi 18:6a4db94011d3 119 return (value << 6) | ((value >> 4) & 0x003F); // 10 bit
sahilmgandhi 18:6a4db94011d3 120 }
sahilmgandhi 18:6a4db94011d3 121
sahilmgandhi 18:6a4db94011d3 122 float analogin_read(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 123 uint32_t value = adc_read_u32(obj);
sahilmgandhi 18:6a4db94011d3 124 return (float)value * (1.0f / (float)ADC_RANGE);
sahilmgandhi 18:6a4db94011d3 125 }