Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

targets/hal/TARGET_Silicon_Labs/TARGET_EFM32/analogin_api.c@0:9b334a45a8ff, 2015-10-01 (annotated)

Committer:
bogdanm
Date:
Thu Oct 01 15:25:22 2015 +0300
Revision:
0:9b334a45a8ff
Child:
50:a417edff4437
Initial commit on mbed-dev



Replaces mbed-src (now inactive)

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 0:9b334a45a8ff 1 /***************************************************************************//**
bogdanm 0:9b334a45a8ff 2 * @file analogin_api.c
bogdanm 0:9b334a45a8ff 3 *******************************************************************************
bogdanm 0:9b334a45a8ff 4 * @section License
bogdanm 0:9b334a45a8ff 5 * <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b>
bogdanm 0:9b334a45a8ff 6 *******************************************************************************
bogdanm 0:9b334a45a8ff 7 *
bogdanm 0:9b334a45a8ff 8 * Permission is granted to anyone to use this software for any purpose,
bogdanm 0:9b334a45a8ff 9 * including commercial applications, and to alter it and redistribute it
bogdanm 0:9b334a45a8ff 10 * freely, subject to the following restrictions:
bogdanm 0:9b334a45a8ff 11 *
bogdanm 0:9b334a45a8ff 12 * 1. The origin of this software must not be misrepresented; you must not
bogdanm 0:9b334a45a8ff 13 * claim that you wrote the original software.
bogdanm 0:9b334a45a8ff 14 * 2. Altered source versions must be plainly marked as such, and must not be
bogdanm 0:9b334a45a8ff 15 * misrepresented as being the original software.
bogdanm 0:9b334a45a8ff 16 * 3. This notice may not be removed or altered from any source distribution.
bogdanm 0:9b334a45a8ff 17 *
bogdanm 0:9b334a45a8ff 18 * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no
bogdanm 0:9b334a45a8ff 19 * obligation to support this Software. Silicon Labs is providing the
bogdanm 0:9b334a45a8ff 20 * Software "AS IS", with no express or implied warranties of any kind,
bogdanm 0:9b334a45a8ff 21 * including, but not limited to, any implied warranties of merchantability
bogdanm 0:9b334a45a8ff 22 * or fitness for any particular purpose or warranties against infringement
bogdanm 0:9b334a45a8ff 23 * of any proprietary rights of a third party.
bogdanm 0:9b334a45a8ff 24 *
bogdanm 0:9b334a45a8ff 25 * Silicon Labs will not be liable for any consequential, incidental, or
bogdanm 0:9b334a45a8ff 26 * special damages, or any other relief, or for any claim by any third party,
bogdanm 0:9b334a45a8ff 27 * arising from your use of this Software.
bogdanm 0:9b334a45a8ff 28 *
bogdanm 0:9b334a45a8ff 29 ******************************************************************************/
bogdanm 0:9b334a45a8ff 30
bogdanm 0:9b334a45a8ff 31 #include "device.h"
bogdanm 0:9b334a45a8ff 32 #if DEVICE_ANALOGIN
bogdanm 0:9b334a45a8ff 33
bogdanm 0:9b334a45a8ff 34 #include "mbed_assert.h"
bogdanm 0:9b334a45a8ff 35 #include "analogin_api.h"
bogdanm 0:9b334a45a8ff 36
bogdanm 0:9b334a45a8ff 37 #include "pinmap.h"
bogdanm 0:9b334a45a8ff 38 #include "pinmap_function.h"
bogdanm 0:9b334a45a8ff 39 #include "PeripheralPins.h"
bogdanm 0:9b334a45a8ff 40
bogdanm 0:9b334a45a8ff 41 #include "em_adc.h"
bogdanm 0:9b334a45a8ff 42 #include "em_cmu.h"
bogdanm 0:9b334a45a8ff 43
bogdanm 0:9b334a45a8ff 44 uint8_t analogin_get_index(analogin_t *obj)
bogdanm 0:9b334a45a8ff 45 {
bogdanm 0:9b334a45a8ff 46 return 0; //only one module availalbe
bogdanm 0:9b334a45a8ff 47 }
bogdanm 0:9b334a45a8ff 48
bogdanm 0:9b334a45a8ff 49 void analogin_preinit(analogin_t *obj, PinName pin)
bogdanm 0:9b334a45a8ff 50 {
bogdanm 0:9b334a45a8ff 51 obj->adc = (ADC_TypeDef *) pinmap_peripheral(pin, PinMap_ADC);
bogdanm 0:9b334a45a8ff 52 MBED_ASSERT((int) obj->adc != NC);
bogdanm 0:9b334a45a8ff 53
bogdanm 0:9b334a45a8ff 54 obj->channel = pin_location(pin, PinMap_ADC);
bogdanm 0:9b334a45a8ff 55 MBED_ASSERT((int) obj->channel != NC);
bogdanm 0:9b334a45a8ff 56 }
bogdanm 0:9b334a45a8ff 57
bogdanm 0:9b334a45a8ff 58 void analogin_init(analogin_t *obj, PinName pin)
bogdanm 0:9b334a45a8ff 59 {
bogdanm 0:9b334a45a8ff 60 static uint8_t adc_initialized = 0;
bogdanm 0:9b334a45a8ff 61
bogdanm 0:9b334a45a8ff 62 /* Init structure */
bogdanm 0:9b334a45a8ff 63 analogin_preinit(obj, pin);
bogdanm 0:9b334a45a8ff 64
bogdanm 0:9b334a45a8ff 65 /* Only initialize the ADC once */
bogdanm 0:9b334a45a8ff 66 if (!adc_initialized) {
bogdanm 0:9b334a45a8ff 67 /* Turn on the clock */
bogdanm 0:9b334a45a8ff 68 CMU_ClockEnable(cmuClock_ADC0, true);
bogdanm 0:9b334a45a8ff 69
bogdanm 0:9b334a45a8ff 70 /* Init with default settings */
bogdanm 0:9b334a45a8ff 71 ADC_Init_TypeDef init = ADC_INIT_DEFAULT;
bogdanm 0:9b334a45a8ff 72 init.prescale = 4;
bogdanm 0:9b334a45a8ff 73 ADC_Init(obj->adc, &init);
bogdanm 0:9b334a45a8ff 74
bogdanm 0:9b334a45a8ff 75 /* Init for single conversion use */
bogdanm 0:9b334a45a8ff 76 ADC_InitSingle_TypeDef singleInit = ADC_INITSINGLE_DEFAULT;
bogdanm 0:9b334a45a8ff 77
bogdanm 0:9b334a45a8ff 78 /* Measure input channel with Vdd reference. */
bogdanm 0:9b334a45a8ff 79 singleInit.reference = adcRefVDD;
bogdanm 0:9b334a45a8ff 80 singleInit.resolution = adcRes12Bit;
bogdanm 0:9b334a45a8ff 81 singleInit.acqTime = adcAcqTime32;
bogdanm 0:9b334a45a8ff 82
bogdanm 0:9b334a45a8ff 83 ADC_InitSingle(obj->adc, &singleInit);
bogdanm 0:9b334a45a8ff 84
bogdanm 0:9b334a45a8ff 85 adc_initialized = 1;
bogdanm 0:9b334a45a8ff 86 }
bogdanm 0:9b334a45a8ff 87 }
bogdanm 0:9b334a45a8ff 88
bogdanm 0:9b334a45a8ff 89 void analogin_enable(analogin_t *obj, uint8_t enable)
bogdanm 0:9b334a45a8ff 90 {
bogdanm 0:9b334a45a8ff 91 //not avail for EFM32
bogdanm 0:9b334a45a8ff 92 }
bogdanm 0:9b334a45a8ff 93
bogdanm 0:9b334a45a8ff 94 void analogin_enable_pins(analogin_t *obj, uint8_t enable)
bogdanm 0:9b334a45a8ff 95 {
bogdanm 0:9b334a45a8ff 96 //not avail for EFM32
bogdanm 0:9b334a45a8ff 97 }
bogdanm 0:9b334a45a8ff 98
bogdanm 0:9b334a45a8ff 99 void analogin_enable_interrupt(analogin_t *obj, uint32_t address, uint8_t enable)
bogdanm 0:9b334a45a8ff 100 {
bogdanm 0:9b334a45a8ff 101 NVIC_SetVector(ADC0_IRQn, address);
bogdanm 0:9b334a45a8ff 102 if (enable) {
bogdanm 0:9b334a45a8ff 103 // enable end of conversion interrupt
bogdanm 0:9b334a45a8ff 104 ADC_IntEnable(obj->adc, ADC_IEN_SCAN);
bogdanm 0:9b334a45a8ff 105 ADC_IntSet(obj->adc, ADC_IF_SCAN);
bogdanm 0:9b334a45a8ff 106 NVIC_EnableIRQ(ADC0_IRQn);
bogdanm 0:9b334a45a8ff 107 } else {
bogdanm 0:9b334a45a8ff 108 ADC_IntDisable(obj->adc, ADC_IEN_SCAN);
bogdanm 0:9b334a45a8ff 109 ADC_IntClear(obj->adc, ADC_IF_SCAN);
bogdanm 0:9b334a45a8ff 110 NVIC_DisableIRQ(ADC0_IRQn);
bogdanm 0:9b334a45a8ff 111 }
bogdanm 0:9b334a45a8ff 112 }
bogdanm 0:9b334a45a8ff 113
bogdanm 0:9b334a45a8ff 114 uint16_t analogin_read_u16(analogin_t *obj)
bogdanm 0:9b334a45a8ff 115 {
bogdanm 0:9b334a45a8ff 116 ADC_TypeDef *adc = obj->adc;
bogdanm 0:9b334a45a8ff 117 uint16_t sample = 0;
bogdanm 0:9b334a45a8ff 118
bogdanm 0:9b334a45a8ff 119 //Make sure a single conversion is not in progress
bogdanm 0:9b334a45a8ff 120 adc->CMD = ADC_CMD_SINGLESTOP;
bogdanm 0:9b334a45a8ff 121
bogdanm 0:9b334a45a8ff 122 // Make sure we are checking the correct channel
bogdanm 0:9b334a45a8ff 123 adc->SINGLECTRL = (adc->SINGLECTRL & ~_ADC_SINGLECTRL_INPUTSEL_MASK) | obj->channel;
bogdanm 0:9b334a45a8ff 124
bogdanm 0:9b334a45a8ff 125 ADC_Start(adc, adcStartSingle);
bogdanm 0:9b334a45a8ff 126
bogdanm 0:9b334a45a8ff 127 /* Wait while conversion is active */
bogdanm 0:9b334a45a8ff 128 while (adc->STATUS & ADC_STATUS_SINGLEACT);
bogdanm 0:9b334a45a8ff 129
bogdanm 0:9b334a45a8ff 130 /* Get ADC result */
bogdanm 0:9b334a45a8ff 131 sample = ADC_DataSingleGet(adc);
bogdanm 0:9b334a45a8ff 132
bogdanm 0:9b334a45a8ff 133 /* The ADC has 12 bit resolution. We shift in 4 0s */
bogdanm 0:9b334a45a8ff 134 /* from the right to make it a 16 bit number as expected */
bogdanm 0:9b334a45a8ff 135 return sample << 4;
bogdanm 0:9b334a45a8ff 136 }
bogdanm 0:9b334a45a8ff 137
bogdanm 0:9b334a45a8ff 138 float analogin_read(analogin_t *obj)
bogdanm 0:9b334a45a8ff 139 {
bogdanm 0:9b334a45a8ff 140 /* Convert from a uint16 to a float between 0 and 1 by division by 0xFFFF */
bogdanm 0:9b334a45a8ff 141 return analogin_read_u16(obj) / (float) 0xFFFF;
bogdanm 0:9b334a45a8ff 142 }
bogdanm 0:9b334a45a8ff 143
bogdanm 0:9b334a45a8ff 144 #endif