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 "analogin_api.h"
36 #include "PeripheralPins.h"
38 ADC_HandleTypeDef AdcHandle
;
42 void analogin_init(analogin_t
*obj
, PinName pin
)
44 // Get the peripheral name from the pin and assign it to the object
45 obj
->adc
= (ADCName
)pinmap_peripheral(pin
, PinMap_ADC
);
46 MBED_ASSERT(obj
->adc
!= (ADCName
)NC
);
48 // Get the functions (adc channel) from the pin and assign it to the object
49 uint32_t function
= pinmap_function(pin
, PinMap_ADC
);
50 MBED_ASSERT(function
!= (uint32_t)NC
);
51 obj
->channel
= STM_PIN_CHANNEL(function
);
54 pinmap_pinout(pin
, PinMap_ADC
);
56 // Save pin number for the read function
59 // The ADC initialization is done once
60 if (adc_inited
== 0) {
67 AdcHandle
.Instance
= (ADC_TypeDef
*)(obj
->adc
);
68 AdcHandle
.Init
.ClockPrescaler
= ADC_CLOCKPRESCALER_PCLK_DIV2
;
69 AdcHandle
.Init
.Resolution
= ADC_RESOLUTION12b
;
70 AdcHandle
.Init
.ScanConvMode
= DISABLE
;
71 AdcHandle
.Init
.ContinuousConvMode
= DISABLE
;
72 AdcHandle
.Init
.DiscontinuousConvMode
= DISABLE
;
73 AdcHandle
.Init
.NbrOfDiscConversion
= 0;
74 AdcHandle
.Init
.ExternalTrigConvEdge
= ADC_EXTERNALTRIGCONVEDGE_NONE
;
75 AdcHandle
.Init
.ExternalTrigConv
= ADC_EXTERNALTRIGCONV_T1_CC1
;
76 AdcHandle
.Init
.DataAlign
= ADC_DATAALIGN_RIGHT
;
77 AdcHandle
.Init
.NbrOfConversion
= 1;
78 AdcHandle
.Init
.DMAContinuousRequests
= DISABLE
;
79 AdcHandle
.Init
.EOCSelection
= DISABLE
;
80 HAL_ADC_Init(&AdcHandle
);
84 static inline uint16_t adc_read(analogin_t
*obj
)
86 ADC_ChannelConfTypeDef sConfig
;
88 AdcHandle
.Instance
= (ADC_TypeDef
*)(obj
->adc
);
90 // Configure ADC channel
92 sConfig
.SamplingTime
= ADC_SAMPLETIME_3CYCLES
;
95 switch (obj
->channel
) {
97 sConfig
.Channel
= ADC_CHANNEL_0
;
100 sConfig
.Channel
= ADC_CHANNEL_1
;
103 sConfig
.Channel
= ADC_CHANNEL_2
;
106 sConfig
.Channel
= ADC_CHANNEL_3
;
109 sConfig
.Channel
= ADC_CHANNEL_4
;
112 sConfig
.Channel
= ADC_CHANNEL_5
;
115 sConfig
.Channel
= ADC_CHANNEL_6
;
118 sConfig
.Channel
= ADC_CHANNEL_7
;
121 sConfig
.Channel
= ADC_CHANNEL_8
;
124 sConfig
.Channel
= ADC_CHANNEL_9
;
127 sConfig
.Channel
= ADC_CHANNEL_10
;
130 sConfig
.Channel
= ADC_CHANNEL_11
;
133 sConfig
.Channel
= ADC_CHANNEL_12
;
136 sConfig
.Channel
= ADC_CHANNEL_13
;
139 sConfig
.Channel
= ADC_CHANNEL_14
;
142 sConfig
.Channel
= ADC_CHANNEL_15
;
148 HAL_ADC_ConfigChannel(&AdcHandle
, &sConfig
);
150 HAL_ADC_Start(&AdcHandle
); // Start conversion
152 // Wait end of conversion and get value
153 if (HAL_ADC_PollForConversion(&AdcHandle
, 10) == HAL_OK
) {
154 return (HAL_ADC_GetValue(&AdcHandle
));
160 uint16_t analogin_read_u16(analogin_t
*obj
)
162 uint16_t value
= adc_read(obj
);
163 // 12-bit to 16-bit conversion
164 value
= ((value
<< 4) & (uint16_t)0xFFF0) | ((value
>> 8) & (uint16_t)0x000F);
168 float analogin_read(analogin_t
*obj
)
170 uint16_t value
= adc_read(obj
);
171 return (float)value
* (1.0f
/ (float)0xFFF); // 12 bits range