mbed library sources
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Diff: targets/hal/TARGET_NXP/TARGET_LPC11U6X/analogin_api.c
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- 186:2e805bf06ee4
- Child:
- 193:cff126de7aaf
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/hal/TARGET_NXP/TARGET_LPC11U6X/analogin_api.c Mon May 12 10:15:06 2014 +0100 @@ -0,0 +1,131 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "analogin_api.h" +#include "cmsis.h" +#include "pinmap.h" +#include "error.h" + +#ifdef DEVICE_ANALOGIN + +#define ANALOGIN_MEDIAN_FILTER 1 + +#define ADC_10BIT_RANGE 0x3FF +#define ADC_12BIT_RANGE 0xFFF +#define PDRUN_VALID_BITS 0x000025FFL +#define PDRUN_RESERVED_ONE 0x0000C800L + +#define ADC_RANGE ADC_12BIT_RANGE + +static const PinMap PinMap_ADC[] = { + {P1_9 , ADC_0, 3}, + {P0_23, ADC_1, 1}, + {P0_16, ADC_2, 1}, + {P0_15, ADC_3, 3}, + {P1_22, ADC_4, 3}, + {P1_3 , ADC_5, 4}, + {P0_14, ADC_6, 2}, + {P0_13, ADC_7, 2}, + {P0_12, ADC_8, 2}, + {P0_11, ADC_9, 2}, + {P1_29, ADC_10,4}, + {P0_22, ADC_11,1}, + {NC , NC ,0} +}; + + +void analogin_init(analogin_t *obj, PinName pin) { + volatile uint32_t tmp; + obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC); + if (obj->adc == (uint32_t)NC) { + error("ADC pin mapping failed"); + } + pinmap_pinout(pin, PinMap_ADC); + + // ADC Powered + tmp = (LPC_SYSCON->PDRUNCFG & PDRUN_VALID_BITS); + tmp &= ~((1 << 4) & PDRUN_VALID_BITS); + LPC_SYSCON->PDRUNCFG = (tmp | PDRUN_RESERVED_ONE); + + // Enable clock for ADC + LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 13); + + // Start ADC self-calibration + LPC_ADC->CTRL = (1UL << 30) || (100); + do { + tmp = LPC_ADC->CTRL; + } while ((tmp & (1UL << 30)) != 0); + + LPC_ADC->CTRL = 100; +} + +static inline uint32_t adc_read(analogin_t *obj) { + + // select channel + LPC_ADC->SEQA_CTRL &= ~(0xFFF); + LPC_ADC->SEQA_CTRL |= (1UL << obj->adc); + + // start conversion, sequence enable with async mode + LPC_ADC->SEQA_CTRL |= ((1UL << 26) | (1UL << 31) | (1UL << 29) /*| (1UL << 19)*/); + + // Repeatedly get the sample data until DONE bit + volatile uint32_t data; + do { + data = LPC_ADC->SEQA_GDAT; + } while ((data & (1UL << 31)) == 0); + data = LPC_ADC->DAT[obj->adc]; + + // Stop conversion + LPC_ADC->SEQA_CTRL &= ~(1UL << 31); + + return ((data >> 4) & ADC_RANGE); +} + +static inline void order(uint32_t *a, uint32_t *b) { + if (*a > *b) { + uint32_t t = *a; + *a = *b; + *b = t; + } +} + +static inline uint32_t adc_read_u32(analogin_t *obj) { + uint32_t value; +#if ANALOGIN_MEDIAN_FILTER + uint32_t v1 = adc_read(obj); + uint32_t v2 = adc_read(obj); + uint32_t v3 = adc_read(obj); + order(&v1, &v2); + order(&v2, &v3); + order(&v1, &v2); + value = v2; +#else + value = adc_read(obj); +#endif + return value; +} + +uint16_t analogin_read_u16(analogin_t *obj) { + uint32_t value = adc_read_u32(obj); + return (value << 4) | ((value >> 8) & 0x000F); // 12 bit +} + +float analogin_read(analogin_t *obj) { + uint32_t value = adc_read_u32(obj); + return (float)value * (1.0f / (float)ADC_RANGE); +} + +#endif