Diff: targets/hal/TARGET_STM/TARGET_STM32F4XX/analogin_api.c

Revision:

20:4263a77256ae

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_STM/TARGET_STM32F4XX/analogin_api.c	Tue Sep 10 15:14:19 2013 +0300
@@ -0,0 +1,97 @@
+/* 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"
+
+#if DEVICE_ANALOGIN
+
+#include "cmsis.h"
+#include "pinmap.h"
+#include "error.h"
+
+#define ADC_10BIT_RANGE             0x3FF
+#define ADC_12BIT_RANGE             0xFFF
+
+static const PinMap PinMap_ADC[] = {
+    {PA_0, ADC0_0,  STM_PIN_DATA(3, 0)},
+    {PA_1, ADC0_1,  STM_PIN_DATA(3, 0)},
+    {PA_2, ADC0_2,  STM_PIN_DATA(3, 0)},
+    {PA_3, ADC0_3,  STM_PIN_DATA(3, 0)},
+    {PA_4, ADC0_4,  STM_PIN_DATA(3, 0)},
+    {PA_5, ADC0_5,  STM_PIN_DATA(3, 0)},
+    {PA_6, ADC0_6,  STM_PIN_DATA(3, 0)},
+    {PA_7, ADC0_7,  STM_PIN_DATA(3, 0)},
+    {PB_0, ADC0_8,  STM_PIN_DATA(3, 0)},
+    {PB_1, ADC0_9,  STM_PIN_DATA(3, 0)},
+    {PC_0, ADC0_10, STM_PIN_DATA(3, 0)},
+    {PC_1, ADC0_11, STM_PIN_DATA(3, 0)},
+    {PC_2, ADC0_12, STM_PIN_DATA(3, 0)},
+    {PC_3, ADC0_13, STM_PIN_DATA(3, 0)},
+    {PC_4, ADC0_14, STM_PIN_DATA(3, 0)},
+    {PC_5, ADC0_15, STM_PIN_DATA(3, 0)},
+    {NC,   NC,      0}
+};
+
+#   define ADC_RANGE    ADC_12BIT_RANGE
+
+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");
+    }
+
+    // ensure power is turned on
+    RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN | RCC_AHB1ENR_GPIOBEN |
+                    RCC_AHB1ENR_GPIOCEN;
+    RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
+
+    // Enable the ADC
+    ADC1->CR2 |= ADC_CR2_ADON;
+
+    pinmap_pinout(pin, PinMap_ADC);
+}
+
+static inline uint32_t adc_read(analogin_t *obj) {
+    // Select the appropriate channel
+    ADC1->SQR3 = (int) obj->adc;
+
+    // Start conversion
+    ADC1->CR2 |= ADC_CR2_SWSTART;
+
+    // Wait for conversion to finish
+    while (!(ADC1->SR & ADC_SR_EOC));
+
+    uint32_t data = ADC1->DR;
+    return data; // 12 bit
+}
+
+static inline uint32_t adc_read_u32(analogin_t *obj) {
+    uint32_t value;
+    value = adc_read(obj);
+    return value;
+}
+
+uint16_t analogin_read_u16(analogin_t *obj) {
+    uint32_t value = adc_read_u32(obj);
+
+    return (value << 4) | ((value >> 8) & 0x000F); // 12 bit
+}
+
+float analogin_read(analogin_t *obj) {
+    uint32_t value = adc_read_u32(obj);
+    return (float)value * (1.0f / (float)ADC_RANGE);
+}
+
+#endif