tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32F1/analogin_api.c

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2014, STMicroelectronics
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright notice,
   9  *    this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright notice,
  11  *    this list of conditions and the following disclaimer in the documentation
  12  *    and/or other materials provided with the distribution.
  13  * 3. Neither the name of STMicroelectronics nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  24  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28 #include "mbed_assert.h"
  29 #include "analogin_api.h"
  30
  31 #if DEVICE_ANALOGIN
  32
  33 #include "wait_api.h"
  34 #include "cmsis.h"
  35 #include "pinmap.h"
  36 #include "PeripheralPins.h"
  37
  38 ADC_HandleTypeDef AdcHandle;
  39
  40 int adc_inited = 0;
  41
  42 void analogin_init(analogin_t *obj, PinName pin)
  43 {
  44     RCC_PeriphCLKInitTypeDef  PeriphClkInit;
  45
  46     // Get the peripheral name from the pin and assign it to the object
  47     obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
  48     MBED_ASSERT(obj->adc != (ADCName)NC);
  49
  50     // Configure GPIO
  51     pinmap_pinout(pin, PinMap_ADC);
  52
  53     // Save pin number for the read function
  54     obj->pin = pin;
  55
  56     // The ADC initialization is done once
  57     if (adc_inited == 0) {
  58         adc_inited = 1;
  59
  60         // Enable ADC clock
  61         __HAL_RCC_ADC1_CLK_ENABLE();
  62
  63         // Configure ADC clock prescaler
  64         // Caution: On STM32F1, ADC clock frequency max is 14 MHz (refer to device datasheet).
  65         // Therefore, ADC clock prescaler must be configured in function
  66         // of ADC clock source frequency to remain below this maximum frequency.
  67         // with 8 MHz external xtal: PCLK2 = 72 MHz --> ADC clock = 72/6 = 12 MHz
  68         // with internal clock     : PCLK2 = 64 MHz --> ADC clock = 64/6 = 10.67 MHz
  69         PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_ADC;
  70         PeriphClkInit.AdcClockSelection = RCC_ADCPCLK2_DIV6;
  71         HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);
  72
  73         // Configure ADC
  74         AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);
  75         AdcHandle.Init.DataAlign             = ADC_DATAALIGN_RIGHT;
  76         AdcHandle.Init.ScanConvMode          = DISABLE;
  77         AdcHandle.Init.ContinuousConvMode    = DISABLE;
  78         AdcHandle.Init.NbrOfConversion       = 1;
  79         AdcHandle.Init.DiscontinuousConvMode = DISABLE;
  80         AdcHandle.Init.NbrOfDiscConversion   = 0;
  81         AdcHandle.Init.ExternalTrigConv      = ADC_EXTERNALTRIGCONV_T1_CC1;
  82         HAL_ADC_Init(&AdcHandle);
  83     }
  84 }
  85
  86 static inline uint16_t adc_read(analogin_t *obj)
  87 {
  88     ADC_ChannelConfTypeDef sConfig;
  89
  90     AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);
  91
  92     // Configure ADC channel
  93     sConfig.Rank         = 1;
  94     sConfig.SamplingTime = ADC_SAMPLETIME_7CYCLES_5;
  95
  96     switch (obj->pin) {
  97         case PA_0:
  98             sConfig.Channel = ADC_CHANNEL_0;
  99             break;
 100         case PA_1:
 101             sConfig.Channel = ADC_CHANNEL_1;
 102             break;
 103         case PA_2:
 104             sConfig.Channel = ADC_CHANNEL_2;
 105             break;
 106         case PA_3:
 107             sConfig.Channel = ADC_CHANNEL_3;
 108             break;
 109         case PA_4:
 110             sConfig.Channel = ADC_CHANNEL_4;
 111             break;
 112         case PA_5:
 113             sConfig.Channel = ADC_CHANNEL_5;
 114             break;
 115         case PA_6:
 116             sConfig.Channel = ADC_CHANNEL_6;
 117             break;
 118         case PA_7:
 119             sConfig.Channel = ADC_CHANNEL_7;
 120             break;
 121         case PB_0:
 122             sConfig.Channel = ADC_CHANNEL_8;
 123             break;
 124         case PB_1:
 125             sConfig.Channel = ADC_CHANNEL_9;
 126             break;
 127         case PC_0:
 128             sConfig.Channel = ADC_CHANNEL_10;
 129             break;
 130         case PC_1:
 131             sConfig.Channel = ADC_CHANNEL_11;
 132             break;
 133         case PC_2:
 134             sConfig.Channel = ADC_CHANNEL_12;
 135             break;
 136         case PC_3:
 137             sConfig.Channel = ADC_CHANNEL_13;
 138             break;
 139         case PC_4:
 140             sConfig.Channel = ADC_CHANNEL_14;
 141             break;
 142         case PC_5:
 143             sConfig.Channel = ADC_CHANNEL_15;
 144             break;
 145         default:
 146             return 0;
 147     }
 148
 149     HAL_ADC_ConfigChannel(&AdcHandle, &sConfig);
 150
 151     HAL_ADC_Start(&AdcHandle); // Start conversion
 152
 153     // Wait end of conversion and get value
 154     if (HAL_ADC_PollForConversion(&AdcHandle, 10) == HAL_OK) {
 155         return (HAL_ADC_GetValue(&AdcHandle));
 156     } else {
 157         return 0;
 158     }
 159 }
 160
 161 uint16_t analogin_read_u16(analogin_t *obj)
 162 {
 163     uint16_t value = adc_read(obj);
 164     // 12-bit to 16-bit conversion
 165     value = ((value << 4) & (uint16_t)0xFFF0) | ((value >> 8) & (uint16_t)0x000F);
 166     return value;
 167 }
 168
 169 float analogin_read(analogin_t *obj)
 170 {
 171     uint16_t value = adc_read(obj);
 172     return (float)value * (1.0f / (float)0xFFF); // 12 bits range
 173 }
 174
 175 #endif