/* 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" static const PinMap PinMap_ADC[] = { {PTE20, ADC0_SE0, 0}, {PTE21, ADC0_SE4a, 0}, {PTE22, ADC0_SE3, 0}, {PTE23, ADC0_SE7a, 0}, {PTE29, ADC0_SE4b, 0}, {PTE30, ADC0_SE23, 0}, {PTB0, ADC0_SE8, 0}, {PTB1, ADC0_SE9, 0}, {PTB2, ADC0_SE12, 0}, {PTB3, ADC0_SE13, 0}, {PTC0, ADC0_SE14, 0}, {PTC1, ADC0_SE15, 0}, {PTC2, ADC0_SE11, 0}, {PTD1, ADC0_SE5b, 0}, {PTD5, ADC0_SE6b, 0}, {PTD6, ADC0_SE7b, 0}, {NC, NC, 0} }; void analogin_init(analogin_t *obj, PinName pin) { obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC); if (obj->adc == (uint32_t)NC) { error("ADC pin mapping failed"); } SIM->SCGC6 |= SIM_SCGC6_ADC0_MASK; uint32_t port = (uint32_t)pin >> PORT_SHIFT; SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port); ADC0->SC1[1] = ADC_SC1_ADCH(obj->adc); ADC0->CFG1 = ADC_CFG1_ADLPC_MASK // Low-Power Configuration | ADC_CFG1_ADIV(3) // Clock Divide Select: (Input Clock)/8 | ADC_CFG1_ADLSMP_MASK // Long Sample Time | ADC_CFG1_MODE(3) // (16)bits Resolution | ADC_CFG1_ADICLK(1); // Input Clock: (Bus Clock)/2 ADC0->CFG2 = ADC_CFG2_MUXSEL_MASK // ADxxb channels are selected | ADC_CFG2_ADACKEN_MASK // Asynchronous Clock Output Enable | ADC_CFG2_ADHSC_MASK // High-Speed Configuration | ADC_CFG2_ADLSTS(0); // Long Sample Time Select ADC0->SC2 = ADC_SC2_REFSEL(0); // Default Voltage Reference ADC0->SC3 = ADC_SC3_AVGE_MASK // Hardware Average Enable | ADC_SC3_AVGS(0); // 4 Samples Averaged pinmap_pinout(pin, PinMap_ADC); } uint16_t analogin_read_u16(analogin_t *obj) { // start conversion ADC0->SC1[0] = ADC_SC1_ADCH(obj->adc); // Wait Conversion Complete while ((ADC0->SC1[0] & ADC_SC1_COCO_MASK) != ADC_SC1_COCO_MASK); // Return value return (uint16_t)ADC0->R[0]; } float analogin_read(analogin_t *obj) { uint16_t value = analogin_read_u16(obj); return (float)value * (1.0f / (float)0xFFFF); }