Diff: targets/TARGET_STM/TARGET_STM32F1/analogin_api.c

Revision:

149:156823d33999

Child:

150:02e0a0aed4ec

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_STM/TARGET_STM32F1/analogin_api.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,188 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2016, STMicroelectronics
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of STMicroelectronics nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "mbed_assert.h"
+#include "analogin_api.h"
+
+#if DEVICE_ANALOGIN
+
+#include "wait_api.h"
+#include "cmsis.h"
+#include "pinmap.h"
+#include "PeripheralPins.h"
+
+ADC_HandleTypeDef AdcHandle;
+
+int adc_inited = 0;
+
+void analogin_init(analogin_t *obj, PinName pin)
+{
+    RCC_PeriphCLKInitTypeDef  PeriphClkInit;
+
+    // Get the peripheral name from the pin and assign it to the object
+    obj->adc = (ADCName)pinmap_peripheral(pin, PinMap_ADC);
+    MBED_ASSERT(obj->adc != (ADCName)NC);
+    
+    // Get the functions (adc channel) from the pin and assign it to the object
+    uint32_t function = pinmap_function(pin, PinMap_ADC);
+    MBED_ASSERT(function != (uint32_t)NC);
+    obj->channel = STM_PIN_CHANNEL(function);
+
+    // Configure GPIO excepted for internal channels (Temperature, Vref)
+    if ((obj->channel != 16) && (obj->channel != 17)) {
+        pinmap_pinout(pin, PinMap_ADC);
+    }
+
+    // Save pin number for the read function
+    obj->pin = pin;
+
+    // The ADC initialization is done once
+    if (adc_inited == 0) {
+        adc_inited = 1;
+
+        // Enable ADC clock
+        __HAL_RCC_ADC1_CLK_ENABLE();
+
+        // Configure ADC clock prescaler
+        // Caution: On STM32F1, ADC clock frequency max is 14 MHz (refer to device datasheet).
+        // Therefore, ADC clock prescaler must be configured in function
+        // of ADC clock source frequency to remain below this maximum frequency.
+        // with 8 MHz external xtal: PCLK2 = 72 MHz --> ADC clock = 72/6 = 12 MHz
+        // with internal clock     : PCLK2 = 64 MHz --> ADC clock = 64/6 = 10.67 MHz
+        PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_ADC;
+        PeriphClkInit.AdcClockSelection = RCC_ADCPCLK2_DIV6;
+        HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);
+
+        // Configure ADC
+        AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);
+        AdcHandle.Init.DataAlign             = ADC_DATAALIGN_RIGHT;
+        AdcHandle.Init.ScanConvMode          = DISABLE;
+        AdcHandle.Init.ContinuousConvMode    = DISABLE;
+        AdcHandle.Init.NbrOfConversion       = 1;
+        AdcHandle.Init.DiscontinuousConvMode = DISABLE;
+        AdcHandle.Init.NbrOfDiscConversion   = 0;
+        AdcHandle.Init.ExternalTrigConv      = ADC_SOFTWARE_START;
+        HAL_ADC_Init(&AdcHandle);
+    }
+}
+
+static inline uint16_t adc_read(analogin_t *obj)
+{
+    ADC_ChannelConfTypeDef sConfig;
+
+    AdcHandle.Instance = (ADC_TypeDef *)(obj->adc);
+
+    // Configure ADC channel
+    sConfig.Rank         = 1;
+    sConfig.SamplingTime = ADC_SAMPLETIME_7CYCLES_5;
+
+    switch (obj->channel) {
+        case 0:
+            sConfig.Channel = ADC_CHANNEL_0;
+            break;
+        case 1:
+            sConfig.Channel = ADC_CHANNEL_1;
+            break;
+        case 2:
+            sConfig.Channel = ADC_CHANNEL_2;
+            break;
+        case 3:
+            sConfig.Channel = ADC_CHANNEL_3;
+            break;
+        case 4:
+            sConfig.Channel = ADC_CHANNEL_4;
+            break;
+        case 5:
+            sConfig.Channel = ADC_CHANNEL_5;
+            break;
+        case 6:
+            sConfig.Channel = ADC_CHANNEL_6;
+            break;
+        case 7:
+            sConfig.Channel = ADC_CHANNEL_7;
+            break;
+        case 8:
+            sConfig.Channel = ADC_CHANNEL_8;
+            break;
+        case 9:
+            sConfig.Channel = ADC_CHANNEL_9;
+            break;
+        case 10:
+            sConfig.Channel = ADC_CHANNEL_10;
+            break;
+        case 11:
+            sConfig.Channel = ADC_CHANNEL_11;
+            break;
+        case 12:
+            sConfig.Channel = ADC_CHANNEL_12;
+            break;
+        case 13:
+            sConfig.Channel = ADC_CHANNEL_13;
+            break;
+        case 14:
+            sConfig.Channel = ADC_CHANNEL_14;
+            break;
+        case 15:
+            sConfig.Channel = ADC_CHANNEL_15;
+            break;
+        case 16:
+            sConfig.Channel = ADC_CHANNEL_TEMPSENSOR;
+            break;
+        case 17:
+            sConfig.Channel = ADC_CHANNEL_VREFINT;
+            break;
+        default:
+            return 0;
+    }
+
+    HAL_ADC_ConfigChannel(&AdcHandle, &sConfig);
+
+    HAL_ADC_Start(&AdcHandle); // Start conversion
+
+    // Wait end of conversion and get value
+    if (HAL_ADC_PollForConversion(&AdcHandle, 10) == HAL_OK) {
+        return (HAL_ADC_GetValue(&AdcHandle));
+    } else {
+        return 0;
+    }
+}
+
+uint16_t analogin_read_u16(analogin_t *obj)
+{
+    uint16_t value = adc_read(obj);
+    // 12-bit to 16-bit conversion
+    value = ((value << 4) & (uint16_t)0xFFF0) | ((value >> 8) & (uint16_t)0x000F);
+    return value;
+}
+
+float analogin_read(analogin_t *obj)
+{
+    uint16_t value = adc_read(obj);
+    return (float)value * (1.0f / (float)0xFFF); // 12 bits range
+}
+
+#endif