1 /* mbed Microcontroller Library
2 * Copyright (c) 2014, STMicroelectronics
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
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.
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.
28 #include "mbed_assert.h"
29 #include "analogout_api.h"
35 #include "mbed_error.h"
36 #include "PeripheralPins.h"
38 #define DAC_RANGE (0xFFF) // 12 bits
40 static DAC_HandleTypeDef DacHandle;
42 // These variables are used for the "free" function
43 static int pa4_used = 0;
44 static int pa5_used = 0;
46 void analogout_init(dac_t *obj, PinName pin)
48 DAC_ChannelConfTypeDef sConfig;
50 DacHandle.Instance = DAC;
52 // Get the peripheral name (DAC_1, ...) from the pin and assign it to the object
53 obj->dac = (DACName)pinmap_peripheral(pin, PinMap_DAC);
54 MBED_ASSERT(obj->dac != (DACName)NC);
57 pinmap_pinout(pin, PinMap_DAC);
59 // Save the channel for future use
66 sConfig.DAC_Trigger = DAC_TRIGGER_NONE;
67 sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_DISABLE;
70 HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_1);
73 HAL_DAC_ConfigChannel(&DacHandle, &sConfig, DAC_CHANNEL_2);
77 analogout_write_u16(obj, 0);
80 void analogout_free(dac_t *obj)
82 // Reset DAC and disable clock
83 if (obj->pin == PA_4) pa4_used = 0;
84 if (obj->pin == PA_5) pa5_used = 0;
85 if ((pa4_used == 0) && (pa5_used == 0)) {
87 __DAC_RELEASE_RESET();
92 pin_function(obj->pin, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
95 static inline void dac_write(dac_t *obj, uint16_t value)
97 if (obj->pin == PA_4) {
98 HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_1, DAC_ALIGN_12B_R, value);
99 HAL_DAC_Start(&DacHandle, DAC_CHANNEL_1);
101 HAL_DAC_SetValue(&DacHandle, DAC_CHANNEL_2, DAC_ALIGN_12B_R, value);
102 HAL_DAC_Start(&DacHandle, DAC_CHANNEL_2);
106 static inline int dac_read(dac_t *obj)
108 if (obj->pin == PA_4) {
109 return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_1);
111 return (int)HAL_DAC_GetValue(&DacHandle, DAC_CHANNEL_2);
115 void analogout_write(dac_t *obj, float value)
118 dac_write(obj, 0); // Min value
119 } else if (value > 1.0f) {
120 dac_write(obj, (uint16_t)DAC_RANGE); // Max value
122 dac_write(obj, (uint16_t)(value * (float)DAC_RANGE));
126 void analogout_write_u16(dac_t *obj, uint16_t value)
128 if (value > (uint16_t)DAC_RANGE) {
129 dac_write(obj, (uint16_t)DAC_RANGE); // Max value
131 dac_write(obj, value);
135 float analogout_read(dac_t *obj)
137 uint32_t value = dac_read(obj);
138 return (float)((float)value * (1.0f / (float)DAC_RANGE));
141 uint16_t analogout_read_u16(dac_t *obj)
143 return (uint16_t)dac_read(obj);
146 #endif // DEVICE_ANALOGOUT