Diff: targets/TARGET_STM/TARGET_STM32L1/analogout_api.c

Revision:

149:156823d33999

Parent:

144:ef7eb2e8f9f7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_STM/TARGET_STM32L1/analogout_api.c	Fri Oct 28 11:17:30 2016 +0100
@@ -0,0 +1,136 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2014, 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 "analogout_api.h"
+
+#if DEVICE_ANALOGOUT
+
+#include "cmsis.h"
+#include "pinmap.h"
+#include "mbed_error.h"
+#include "PeripheralPins.h"
+
+#define DAC_RANGE (0xFFF) // 12 bits
+#define DAC_NB_BITS  (12)
+
+static DAC_HandleTypeDef DacHandle;
+
+// These variables are used for the "free" function
+static int pa4_used = 0;
+static int pa5_used = 0;
+
+void analogout_init(dac_t *obj, PinName pin) {
+    DAC_ChannelConfTypeDef sConfig;
+
+    DacHandle.Instance = DAC;
+
+    // Get the peripheral name (DAC_1, ...) from the pin and assign it to the object
+    obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
+    MBED_ASSERT(obj->dac != (DACName)NC);
+
+    // Configure GPIO
+    pinmap_pinout(pin, PinMap_DAC);
+
+    // Save the channel for future use
+    obj->pin = pin;
+
+    // Enable DAC clock
+    __DAC_CLK_ENABLE();
+
+    // Configure DAC
+    sConfig.DAC_Trigger      = DAC_TRIGGER_NONE;
+    sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
+
+    if (pin == PA_4) {
+        HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_1);
+        pa4_used = 1;
+    } else { // PA_5
+        HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_2);
+        pa5_used = 1;
+    }
+
+    analogout_write_u16(obj, 0);
+}
+
+void analogout_free(dac_t *obj) {
+    // Reset DAC and disable clock
+    if (obj->pin == PA_4) pa4_used = 0;
+    if (obj->pin == PA_5) pa5_used = 0;
+    if ((pa4_used == 0) && (pa5_used == 0)) {
+        __DAC_FORCE_RESET();
+        __DAC_RELEASE_RESET();
+        __DAC_CLK_DISABLE();
+    }
+
+    // Configure GPIO
+    pin_function(obj->pin, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
+}
+
+static inline void dac_write(dac_t *obj, int value) {
+    if (obj->pin == PA_4) {
+        HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_1, DAC_ALIGN_12B_R, (value & DAC_RANGE));
+        HAL_DAC_Start(&DacHandle, DAC_CHANNEL_1);
+    } else { // PA_5
+        HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_2, DAC_ALIGN_12B_R, (value & DAC_RANGE));
+        HAL_DAC_Start(&DacHandle, DAC_CHANNEL_2);
+    }
+}
+
+static inline int dac_read(dac_t *obj) {
+    if (obj->pin == PA_4) {
+        return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_1);
+    } else { // PA_5
+        return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_2);
+    }
+}
+
+void analogout_write(dac_t *obj, float value) {
+    if (value < 0.0f) {
+        dac_write(obj, 0); // Min value
+    } else if (value > 1.0f) {
+        dac_write(obj, (int)DAC_RANGE); // Max value
+    } else {
+        dac_write(obj, (int)(value * (float)DAC_RANGE));
+    }
+}
+
+void analogout_write_u16(dac_t *obj, uint16_t value) {
+    dac_write(obj, value >> (16 - DAC_NB_BITS));
+}
+
+float analogout_read(dac_t *obj) {
+    uint32_t value = dac_read(obj);
+    return (float)value * (1.0f / (float)DAC_RANGE);
+}
+
+uint16_t analogout_read_u16(dac_t *obj) {
+    uint32_t value = dac_read(obj);
+    return (value << 4) | ((value >> 8) & 0x000F); // Conversion from 12 to 16 bits
+}
+
+#endif // DEVICE_ANALOGOUT