MacroRat / MouseCode

Mouse code for the MacroRat

Dependencies:   ITG3200 QEI

mbed-dev/targets/TARGET_NXP/TARGET_LPC23XX/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
sahilmgandhi 18:6a4db94011d3 21 #define ANALOGIN_MEDIAN_FILTER 1
sahilmgandhi 18:6a4db94011d3 22
sahilmgandhi 18:6a4db94011d3 23 #define ADC_10BIT_RANGE 0x3FF
sahilmgandhi 18:6a4db94011d3 24 #define ADC_12BIT_RANGE 0xFFF
sahilmgandhi 18:6a4db94011d3 25
sahilmgandhi 18:6a4db94011d3 26 static inline int div_round_up(int x, int y) {
sahilmgandhi 18:6a4db94011d3 27 return (x + (y - 1)) / y;
sahilmgandhi 18:6a4db94011d3 28 }
sahilmgandhi 18:6a4db94011d3 29
sahilmgandhi 18:6a4db94011d3 30 static const PinMap PinMap_ADC[] = {
sahilmgandhi 18:6a4db94011d3 31 {P0_23, ADC0_0, 1},
sahilmgandhi 18:6a4db94011d3 32 {P0_24, ADC0_1, 1},
sahilmgandhi 18:6a4db94011d3 33 {P0_25, ADC0_2, 1},
sahilmgandhi 18:6a4db94011d3 34 {P0_26, ADC0_3, 1},
sahilmgandhi 18:6a4db94011d3 35 {P1_30, ADC0_4, 3},
sahilmgandhi 18:6a4db94011d3 36 {P1_31, ADC0_5, 3},
sahilmgandhi 18:6a4db94011d3 37 {NC, NC, 0}
sahilmgandhi 18:6a4db94011d3 38 };
sahilmgandhi 18:6a4db94011d3 39
sahilmgandhi 18:6a4db94011d3 40 #define ADC_RANGE ADC_10BIT_RANGE
sahilmgandhi 18:6a4db94011d3 41
sahilmgandhi 18:6a4db94011d3 42
sahilmgandhi 18:6a4db94011d3 43 void analogin_init(analogin_t *obj, PinName pin) {
sahilmgandhi 18:6a4db94011d3 44 obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
sahilmgandhi 18:6a4db94011d3 45 MBED_ASSERT(obj->adc != (ADCName)NC);
sahilmgandhi 18:6a4db94011d3 46
sahilmgandhi 18:6a4db94011d3 47 // ensure power is turned on
sahilmgandhi 18:6a4db94011d3 48 LPC_SC->PCONP |= (1 << 12);
sahilmgandhi 18:6a4db94011d3 49
sahilmgandhi 18:6a4db94011d3 50 // set PCLK of ADC to /1
sahilmgandhi 18:6a4db94011d3 51 LPC_SC->PCLKSEL0 &= ~(0x3 << 24);
sahilmgandhi 18:6a4db94011d3 52 LPC_SC->PCLKSEL0 |= (0x1 << 24);
sahilmgandhi 18:6a4db94011d3 53 uint32_t PCLK = SystemCoreClock;
sahilmgandhi 18:6a4db94011d3 54
sahilmgandhi 18:6a4db94011d3 55 // calculate minimum clock divider
sahilmgandhi 18:6a4db94011d3 56 // clkdiv = divider - 1
sahilmgandhi 18:6a4db94011d3 57 uint32_t MAX_ADC_CLK = 13000000;
sahilmgandhi 18:6a4db94011d3 58 uint32_t clkdiv = div_round_up(PCLK, MAX_ADC_CLK) - 1;
sahilmgandhi 18:6a4db94011d3 59
sahilmgandhi 18:6a4db94011d3 60 // Set the generic software-controlled ADC settings
sahilmgandhi 18:6a4db94011d3 61 LPC_ADC->ADCR = (0 << 0) // SEL: 0 = no channels selected
sahilmgandhi 18:6a4db94011d3 62 | (clkdiv << 8) // CLKDIV: PCLK max ~= 25MHz, /25 to give safe 1MHz at fastest
sahilmgandhi 18:6a4db94011d3 63 | (0 << 16) // BURST: 0 = software control
sahilmgandhi 18:6a4db94011d3 64 | (0 << 17) // CLKS: not applicable
sahilmgandhi 18:6a4db94011d3 65 | (1 << 21) // PDN: 1 = operational
sahilmgandhi 18:6a4db94011d3 66 | (0 << 24) // START: 0 = no start
sahilmgandhi 18:6a4db94011d3 67 | (0 << 27); // EDGE: not applicable
sahilmgandhi 18:6a4db94011d3 68
sahilmgandhi 18:6a4db94011d3 69 pinmap_pinout(pin, PinMap_ADC);
sahilmgandhi 18:6a4db94011d3 70 }
sahilmgandhi 18:6a4db94011d3 71
sahilmgandhi 18:6a4db94011d3 72 static inline uint32_t adc_read(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 73 // Select the appropriate channel and start conversion
sahilmgandhi 18:6a4db94011d3 74 LPC_ADC->ADCR &= ~0xFF;
sahilmgandhi 18:6a4db94011d3 75 LPC_ADC->ADCR |= 1 << (int)obj->adc;
sahilmgandhi 18:6a4db94011d3 76 LPC_ADC->ADCR |= 1 << 24;
sahilmgandhi 18:6a4db94011d3 77
sahilmgandhi 18:6a4db94011d3 78 // Repeatedly get the sample data until DONE bit
sahilmgandhi 18:6a4db94011d3 79 unsigned int data;
sahilmgandhi 18:6a4db94011d3 80 do {
sahilmgandhi 18:6a4db94011d3 81 data = LPC_ADC->ADGDR;
sahilmgandhi 18:6a4db94011d3 82 } while ((data & ((unsigned int)1 << 31)) == 0);
sahilmgandhi 18:6a4db94011d3 83
sahilmgandhi 18:6a4db94011d3 84 // Stop conversion
sahilmgandhi 18:6a4db94011d3 85 LPC_ADC->ADCR &= ~(1 << 24);
sahilmgandhi 18:6a4db94011d3 86
sahilmgandhi 18:6a4db94011d3 87 return (data >> 6) & ADC_RANGE; // 10 bit
sahilmgandhi 18:6a4db94011d3 88 }
sahilmgandhi 18:6a4db94011d3 89
sahilmgandhi 18:6a4db94011d3 90 static inline void order(uint32_t *a, uint32_t *b) {
sahilmgandhi 18:6a4db94011d3 91 if (*a > *b) {
sahilmgandhi 18:6a4db94011d3 92 uint32_t t = *a;
sahilmgandhi 18:6a4db94011d3 93 *a = *b;
sahilmgandhi 18:6a4db94011d3 94 *b = t;
sahilmgandhi 18:6a4db94011d3 95 }
sahilmgandhi 18:6a4db94011d3 96 }
sahilmgandhi 18:6a4db94011d3 97
sahilmgandhi 18:6a4db94011d3 98 static inline uint32_t adc_read_u32(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 99 uint32_t value;
sahilmgandhi 18:6a4db94011d3 100 #if ANALOGIN_MEDIAN_FILTER
sahilmgandhi 18:6a4db94011d3 101 uint32_t v1 = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 102 uint32_t v2 = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 103 uint32_t v3 = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 104 order(&v1, &v2);
sahilmgandhi 18:6a4db94011d3 105 order(&v2, &v3);
sahilmgandhi 18:6a4db94011d3 106 order(&v1, &v2);
sahilmgandhi 18:6a4db94011d3 107 value = v2;
sahilmgandhi 18:6a4db94011d3 108 #else
sahilmgandhi 18:6a4db94011d3 109 value = adc_read(obj);
sahilmgandhi 18:6a4db94011d3 110 #endif
sahilmgandhi 18:6a4db94011d3 111 return value;
sahilmgandhi 18:6a4db94011d3 112 }
sahilmgandhi 18:6a4db94011d3 113
sahilmgandhi 18:6a4db94011d3 114 uint16_t analogin_read_u16(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 115 uint32_t value = adc_read_u32(obj);
sahilmgandhi 18:6a4db94011d3 116
sahilmgandhi 18:6a4db94011d3 117 return (value << 6) | ((value >> 4) & 0x003F); // 10 bit
sahilmgandhi 18:6a4db94011d3 118 }
sahilmgandhi 18:6a4db94011d3 119
sahilmgandhi 18:6a4db94011d3 120 float analogin_read(analogin_t *obj) {
sahilmgandhi 18:6a4db94011d3 121 uint32_t value = adc_read_u32(obj);
sahilmgandhi 18:6a4db94011d3 122 return (float)value * (1.0f / (float)ADC_RANGE);
sahilmgandhi 18:6a4db94011d3 123 }