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targets/TARGET_Silicon_Labs/TARGET_EFM32/analogin_api.c@178:c26431f84b0d, 2017-11-09 (annotated)
- Committer:
- amithy
- Date:
- Thu Nov 09 22:14:37 2017 +0000
- Revision:
- 178:c26431f84b0d
- Parent:
- 149:156823d33999
- Child:
- 176:447f873cad2f
test export
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
<> | 144:ef7eb2e8f9f7 | 1 | /***************************************************************************//** |
<> | 144:ef7eb2e8f9f7 | 2 | * @file analogin_api.c |
<> | 144:ef7eb2e8f9f7 | 3 | ******************************************************************************* |
<> | 144:ef7eb2e8f9f7 | 4 | * @section License |
<> | 144:ef7eb2e8f9f7 | 5 | * <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b> |
<> | 144:ef7eb2e8f9f7 | 6 | ******************************************************************************* |
<> | 144:ef7eb2e8f9f7 | 7 | * |
<> | 144:ef7eb2e8f9f7 | 8 | * SPDX-License-Identifier: Apache-2.0 |
<> | 144:ef7eb2e8f9f7 | 9 | * |
<> | 144:ef7eb2e8f9f7 | 10 | * Licensed under the Apache License, Version 2.0 (the "License"); you may |
<> | 144:ef7eb2e8f9f7 | 11 | * not use this file except in compliance with the License. |
<> | 144:ef7eb2e8f9f7 | 12 | * You may obtain a copy of the License at |
<> | 144:ef7eb2e8f9f7 | 13 | * |
<> | 144:ef7eb2e8f9f7 | 14 | * http://www.apache.org/licenses/LICENSE-2.0 |
<> | 144:ef7eb2e8f9f7 | 15 | * |
<> | 144:ef7eb2e8f9f7 | 16 | * Unless required by applicable law or agreed to in writing, software |
<> | 144:ef7eb2e8f9f7 | 17 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
<> | 144:ef7eb2e8f9f7 | 18 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
<> | 144:ef7eb2e8f9f7 | 19 | * See the License for the specific language governing permissions and |
<> | 144:ef7eb2e8f9f7 | 20 | * limitations under the License. |
<> | 144:ef7eb2e8f9f7 | 21 | * |
<> | 144:ef7eb2e8f9f7 | 22 | ******************************************************************************/ |
<> | 144:ef7eb2e8f9f7 | 23 | |
<> | 144:ef7eb2e8f9f7 | 24 | #include "device.h" |
<> | 144:ef7eb2e8f9f7 | 25 | #if DEVICE_ANALOGIN |
<> | 144:ef7eb2e8f9f7 | 26 | |
<> | 144:ef7eb2e8f9f7 | 27 | #include "mbed_assert.h" |
<> | 144:ef7eb2e8f9f7 | 28 | #include "analogin_api.h" |
<> | 144:ef7eb2e8f9f7 | 29 | |
<> | 144:ef7eb2e8f9f7 | 30 | #include "pinmap.h" |
<> | 144:ef7eb2e8f9f7 | 31 | #include "pinmap_function.h" |
<> | 144:ef7eb2e8f9f7 | 32 | #include "PeripheralPins.h" |
<> | 144:ef7eb2e8f9f7 | 33 | |
<> | 144:ef7eb2e8f9f7 | 34 | #include "em_adc.h" |
<> | 144:ef7eb2e8f9f7 | 35 | #include "em_cmu.h" |
<> | 144:ef7eb2e8f9f7 | 36 | |
<> | 144:ef7eb2e8f9f7 | 37 | void analogin_init(analogin_t *obj, PinName pin) |
<> | 144:ef7eb2e8f9f7 | 38 | { |
<> | 144:ef7eb2e8f9f7 | 39 | static uint8_t adc_initialized = 0; |
<> | 144:ef7eb2e8f9f7 | 40 | |
<> | 144:ef7eb2e8f9f7 | 41 | /* Init structure */ |
<> | 144:ef7eb2e8f9f7 | 42 | obj->adc = (ADC_TypeDef *) pinmap_peripheral(pin, PinMap_ADC); |
<> | 144:ef7eb2e8f9f7 | 43 | MBED_ASSERT((int) obj->adc != NC); |
<> | 144:ef7eb2e8f9f7 | 44 | |
<> | 144:ef7eb2e8f9f7 | 45 | obj->channel = pin_location(pin, PinMap_ADC); |
<> | 144:ef7eb2e8f9f7 | 46 | MBED_ASSERT((int) obj->channel != NC); |
<> | 144:ef7eb2e8f9f7 | 47 | |
<> | 144:ef7eb2e8f9f7 | 48 | /* Only initialize the ADC once */ |
<> | 144:ef7eb2e8f9f7 | 49 | if (!adc_initialized) { |
<> | 144:ef7eb2e8f9f7 | 50 | /* Turn on the clock */ |
<> | 144:ef7eb2e8f9f7 | 51 | CMU_ClockEnable(cmuClock_ADC0, true); |
<> | 144:ef7eb2e8f9f7 | 52 | |
<> | 144:ef7eb2e8f9f7 | 53 | /* Init with default settings */ |
<> | 144:ef7eb2e8f9f7 | 54 | ADC_Init_TypeDef init = ADC_INIT_DEFAULT; |
<> | 144:ef7eb2e8f9f7 | 55 | init.prescale = 4; |
<> | 144:ef7eb2e8f9f7 | 56 | ADC_Init(obj->adc, &init); |
<> | 144:ef7eb2e8f9f7 | 57 | |
<> | 144:ef7eb2e8f9f7 | 58 | /* Init for single conversion use */ |
<> | 144:ef7eb2e8f9f7 | 59 | ADC_InitSingle_TypeDef singleInit = ADC_INITSINGLE_DEFAULT; |
<> | 144:ef7eb2e8f9f7 | 60 | |
<> | 144:ef7eb2e8f9f7 | 61 | /* Measure input channel with Vdd reference. */ |
<> | 144:ef7eb2e8f9f7 | 62 | singleInit.reference = adcRefVDD; |
<> | 144:ef7eb2e8f9f7 | 63 | singleInit.resolution = adcRes12Bit; |
<> | 144:ef7eb2e8f9f7 | 64 | singleInit.acqTime = adcAcqTime32; |
<> | 144:ef7eb2e8f9f7 | 65 | |
<> | 144:ef7eb2e8f9f7 | 66 | ADC_InitSingle(obj->adc, &singleInit); |
<> | 144:ef7eb2e8f9f7 | 67 | |
<> | 144:ef7eb2e8f9f7 | 68 | adc_initialized = 1; |
<> | 144:ef7eb2e8f9f7 | 69 | } |
<> | 144:ef7eb2e8f9f7 | 70 | } |
<> | 144:ef7eb2e8f9f7 | 71 | |
<> | 144:ef7eb2e8f9f7 | 72 | uint16_t analogin_read_u16(analogin_t *obj) |
<> | 144:ef7eb2e8f9f7 | 73 | { |
<> | 144:ef7eb2e8f9f7 | 74 | ADC_TypeDef *adc = obj->adc; |
<> | 144:ef7eb2e8f9f7 | 75 | uint16_t sample = 0; |
<> | 144:ef7eb2e8f9f7 | 76 | |
<> | 144:ef7eb2e8f9f7 | 77 | //Make sure a single conversion is not in progress |
<> | 144:ef7eb2e8f9f7 | 78 | adc->CMD = ADC_CMD_SINGLESTOP; |
<> | 144:ef7eb2e8f9f7 | 79 | |
<> | 144:ef7eb2e8f9f7 | 80 | // Make sure we are checking the correct channel |
<> | 144:ef7eb2e8f9f7 | 81 | #if defined _ADC_SINGLECTRL_INPUTSEL_MASK |
<> | 144:ef7eb2e8f9f7 | 82 | adc->SINGLECTRL = (adc->SINGLECTRL & ~_ADC_SINGLECTRL_INPUTSEL_MASK) | obj->channel; |
<> | 144:ef7eb2e8f9f7 | 83 | #elif _ADC_SINGLECTRL_POSSEL_MASK |
<> | 144:ef7eb2e8f9f7 | 84 | adc->SINGLECTRL = (adc->SINGLECTRL & ~_ADC_SINGLECTRL_POSSEL_MASK) | obj->channel << _ADC_SINGLECTRL_POSSEL_SHIFT; |
<> | 144:ef7eb2e8f9f7 | 85 | #endif |
<> | 144:ef7eb2e8f9f7 | 86 | |
<> | 144:ef7eb2e8f9f7 | 87 | ADC_Start(adc, adcStartSingle); |
<> | 144:ef7eb2e8f9f7 | 88 | |
<> | 144:ef7eb2e8f9f7 | 89 | /* Wait while conversion is active */ |
<> | 144:ef7eb2e8f9f7 | 90 | while (adc->STATUS & ADC_STATUS_SINGLEACT); |
<> | 144:ef7eb2e8f9f7 | 91 | |
<> | 144:ef7eb2e8f9f7 | 92 | /* Get ADC result */ |
<> | 144:ef7eb2e8f9f7 | 93 | sample = ADC_DataSingleGet(adc); |
<> | 144:ef7eb2e8f9f7 | 94 | |
<> | 144:ef7eb2e8f9f7 | 95 | /* The ADC has 12 bit resolution. We shift in 4 0s */ |
<> | 144:ef7eb2e8f9f7 | 96 | /* from the right to make it a 16 bit number as expected */ |
<> | 144:ef7eb2e8f9f7 | 97 | return sample << 4; |
<> | 144:ef7eb2e8f9f7 | 98 | } |
<> | 144:ef7eb2e8f9f7 | 99 | |
<> | 144:ef7eb2e8f9f7 | 100 | float analogin_read(analogin_t *obj) |
<> | 144:ef7eb2e8f9f7 | 101 | { |
<> | 144:ef7eb2e8f9f7 | 102 | /* Convert from a uint16 to a float between 0 and 1 by division by 0xFFFF */ |
<> | 144:ef7eb2e8f9f7 | 103 | return analogin_read_u16(obj) / (float) 0xFFFF; |
<> | 144:ef7eb2e8f9f7 | 104 | } |
<> | 144:ef7eb2e8f9f7 | 105 | |
<> | 144:ef7eb2e8f9f7 | 106 | #endif |